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/memblock.h>
24 #include <linux/proc_fs.h>
25 #include <linux/pci.h>
26 #include <linux/pfn.h>
27 #include <linux/poison.h>
28 #include <linux/dma-mapping.h>
29 #include <linux/memory.h>
30 #include <linux/memory_hotplug.h>
31 #include <linux/memremap.h>
32 #include <linux/nmi.h>
33 #include <linux/gfp.h>
34 #include <linux/kcore.h>
36 #include <asm/processor.h>
37 #include <asm/bios_ebda.h>
38 #include <linux/uaccess.h>
39 #include <asm/pgtable.h>
40 #include <asm/pgalloc.h>
42 #include <asm/fixmap.h>
43 #include <asm/e820/api.h>
46 #include <asm/mmu_context.h>
47 #include <asm/proto.h>
49 #include <asm/sections.h>
50 #include <asm/kdebug.h>
52 #include <asm/set_memory.h>
54 #include <asm/uv/uv.h>
55 #include <asm/setup.h>
57 #include "mm_internal.h"
59 #include "ident_map.c"
62 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
63 * physical space so we can cache the place of the first one and move
64 * around without checking the pgd every time.
67 /* Bits supported by the hardware: */
68 pteval_t __supported_pte_mask __read_mostly = ~0;
69 /* Bits allowed in normal kernel mappings: */
70 pteval_t __default_kernel_pte_mask __read_mostly = ~0;
71 EXPORT_SYMBOL_GPL(__supported_pte_mask);
72 /* Used in PAGE_KERNEL_* macros which are reasonably used out-of-tree: */
73 EXPORT_SYMBOL(__default_kernel_pte_mask);
75 int force_personality32;
79 * Control non executable heap for 32bit processes.
80 * To control the stack too use noexec=off
82 * on PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
83 * off PROT_READ implies PROT_EXEC
85 static int __init nonx32_setup(char *str)
87 if (!strcmp(str, "on"))
88 force_personality32 &= ~READ_IMPLIES_EXEC;
89 else if (!strcmp(str, "off"))
90 force_personality32 |= READ_IMPLIES_EXEC;
93 __setup("noexec32=", nonx32_setup);
95 static void sync_global_pgds_l5(unsigned long start, unsigned long end)
99 for (addr = start; addr <= end; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
100 const pgd_t *pgd_ref = pgd_offset_k(addr);
103 /* Check for overflow */
107 if (pgd_none(*pgd_ref))
110 spin_lock(&pgd_lock);
111 list_for_each_entry(page, &pgd_list, lru) {
113 spinlock_t *pgt_lock;
115 pgd = (pgd_t *)page_address(page) + pgd_index(addr);
116 /* the pgt_lock only for Xen */
117 pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
120 if (!pgd_none(*pgd_ref) && !pgd_none(*pgd))
121 BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref));
124 set_pgd(pgd, *pgd_ref);
126 spin_unlock(pgt_lock);
128 spin_unlock(&pgd_lock);
132 static void sync_global_pgds_l4(unsigned long start, unsigned long end)
136 for (addr = start; addr <= end; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
137 pgd_t *pgd_ref = pgd_offset_k(addr);
138 const p4d_t *p4d_ref;
142 * With folded p4d, pgd_none() is always false, we need to
143 * handle synchonization on p4d level.
145 MAYBE_BUILD_BUG_ON(pgd_none(*pgd_ref));
146 p4d_ref = p4d_offset(pgd_ref, addr);
148 if (p4d_none(*p4d_ref))
151 spin_lock(&pgd_lock);
152 list_for_each_entry(page, &pgd_list, lru) {
155 spinlock_t *pgt_lock;
157 pgd = (pgd_t *)page_address(page) + pgd_index(addr);
158 p4d = p4d_offset(pgd, addr);
159 /* the pgt_lock only for Xen */
160 pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
163 if (!p4d_none(*p4d_ref) && !p4d_none(*p4d))
164 BUG_ON(p4d_page_vaddr(*p4d)
165 != p4d_page_vaddr(*p4d_ref));
168 set_p4d(p4d, *p4d_ref);
170 spin_unlock(pgt_lock);
172 spin_unlock(&pgd_lock);
177 * When memory was added 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)
182 if (pgtable_l5_enabled())
183 sync_global_pgds_l5(start, end);
185 sync_global_pgds_l4(start, end);
189 * NOTE: This function is marked __ref because it calls __init function
190 * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
192 static __ref void *spp_getpage(void)
197 ptr = (void *) get_zeroed_page(GFP_ATOMIC);
199 ptr = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
201 if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
202 panic("set_pte_phys: cannot allocate page data %s\n",
203 after_bootmem ? "after bootmem" : "");
206 pr_debug("spp_getpage %p\n", ptr);
211 static p4d_t *fill_p4d(pgd_t *pgd, unsigned long vaddr)
213 if (pgd_none(*pgd)) {
214 p4d_t *p4d = (p4d_t *)spp_getpage();
215 pgd_populate(&init_mm, pgd, p4d);
216 if (p4d != p4d_offset(pgd, 0))
217 printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n",
218 p4d, p4d_offset(pgd, 0));
220 return p4d_offset(pgd, vaddr);
223 static pud_t *fill_pud(p4d_t *p4d, unsigned long vaddr)
225 if (p4d_none(*p4d)) {
226 pud_t *pud = (pud_t *)spp_getpage();
227 p4d_populate(&init_mm, p4d, pud);
228 if (pud != pud_offset(p4d, 0))
229 printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
230 pud, pud_offset(p4d, 0));
232 return pud_offset(p4d, vaddr);
235 static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr)
237 if (pud_none(*pud)) {
238 pmd_t *pmd = (pmd_t *) spp_getpage();
239 pud_populate(&init_mm, pud, pmd);
240 if (pmd != pmd_offset(pud, 0))
241 printk(KERN_ERR "PAGETABLE BUG #02! %p <-> %p\n",
242 pmd, pmd_offset(pud, 0));
244 return pmd_offset(pud, vaddr);
247 static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr)
249 if (pmd_none(*pmd)) {
250 pte_t *pte = (pte_t *) spp_getpage();
251 pmd_populate_kernel(&init_mm, pmd, pte);
252 if (pte != pte_offset_kernel(pmd, 0))
253 printk(KERN_ERR "PAGETABLE BUG #03!\n");
255 return pte_offset_kernel(pmd, vaddr);
258 static void __set_pte_vaddr(pud_t *pud, unsigned long vaddr, pte_t new_pte)
260 pmd_t *pmd = fill_pmd(pud, vaddr);
261 pte_t *pte = fill_pte(pmd, vaddr);
263 set_pte(pte, new_pte);
266 * It's enough to flush this one mapping.
267 * (PGE mappings get flushed as well)
269 __flush_tlb_one_kernel(vaddr);
272 void set_pte_vaddr_p4d(p4d_t *p4d_page, unsigned long vaddr, pte_t new_pte)
274 p4d_t *p4d = p4d_page + p4d_index(vaddr);
275 pud_t *pud = fill_pud(p4d, vaddr);
277 __set_pte_vaddr(pud, vaddr, new_pte);
280 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
282 pud_t *pud = pud_page + pud_index(vaddr);
284 __set_pte_vaddr(pud, vaddr, new_pte);
287 void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
292 pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
294 pgd = pgd_offset_k(vaddr);
295 if (pgd_none(*pgd)) {
297 "PGD FIXMAP MISSING, it should be setup in head.S!\n");
301 p4d_page = p4d_offset(pgd, 0);
302 set_pte_vaddr_p4d(p4d_page, vaddr, pteval);
305 pmd_t * __init populate_extra_pmd(unsigned long vaddr)
311 pgd = pgd_offset_k(vaddr);
312 p4d = fill_p4d(pgd, vaddr);
313 pud = fill_pud(p4d, vaddr);
314 return fill_pmd(pud, vaddr);
317 pte_t * __init populate_extra_pte(unsigned long vaddr)
321 pmd = populate_extra_pmd(vaddr);
322 return fill_pte(pmd, vaddr);
326 * Create large page table mappings for a range of physical addresses.
328 static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
329 enum page_cache_mode cache)
337 pgprot_val(prot) = pgprot_val(PAGE_KERNEL_LARGE) |
338 pgprot_val(pgprot_4k_2_large(cachemode2pgprot(cache)));
339 BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
340 for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
341 pgd = pgd_offset_k((unsigned long)__va(phys));
342 if (pgd_none(*pgd)) {
343 p4d = (p4d_t *) spp_getpage();
344 set_pgd(pgd, __pgd(__pa(p4d) | _KERNPG_TABLE |
347 p4d = p4d_offset(pgd, (unsigned long)__va(phys));
348 if (p4d_none(*p4d)) {
349 pud = (pud_t *) spp_getpage();
350 set_p4d(p4d, __p4d(__pa(pud) | _KERNPG_TABLE |
353 pud = pud_offset(p4d, (unsigned long)__va(phys));
354 if (pud_none(*pud)) {
355 pmd = (pmd_t *) spp_getpage();
356 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
359 pmd = pmd_offset(pud, phys);
360 BUG_ON(!pmd_none(*pmd));
361 set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
365 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
367 __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_WB);
370 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
372 __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_UC);
376 * The head.S code sets up the kernel high mapping:
378 * from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
380 * phys_base holds the negative offset to the kernel, which is added
381 * to the compile time generated pmds. This results in invalid pmds up
382 * to the point where we hit the physaddr 0 mapping.
384 * We limit the mappings to the region from _text to _brk_end. _brk_end
385 * is rounded up to the 2MB boundary. This catches the invalid pmds as
386 * well, as they are located before _text:
388 void __init cleanup_highmap(void)
390 unsigned long vaddr = __START_KERNEL_map;
391 unsigned long vaddr_end = __START_KERNEL_map + KERNEL_IMAGE_SIZE;
392 unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1;
393 pmd_t *pmd = level2_kernel_pgt;
396 * Native path, max_pfn_mapped is not set yet.
397 * Xen has valid max_pfn_mapped set in
398 * arch/x86/xen/mmu.c:xen_setup_kernel_pagetable().
401 vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT);
403 for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) {
406 if (vaddr < (unsigned long) _text || vaddr > end)
407 set_pmd(pmd, __pmd(0));
412 * Create PTE level page table mapping for physical addresses.
413 * It returns the last physical address mapped.
415 static unsigned long __meminit
416 phys_pte_init(pte_t *pte_page, unsigned long paddr, unsigned long paddr_end,
419 unsigned long pages = 0, paddr_next;
420 unsigned long paddr_last = paddr_end;
424 pte = pte_page + pte_index(paddr);
425 i = pte_index(paddr);
427 for (; i < PTRS_PER_PTE; i++, paddr = paddr_next, pte++) {
428 paddr_next = (paddr & PAGE_MASK) + PAGE_SIZE;
429 if (paddr >= paddr_end) {
430 if (!after_bootmem &&
431 !e820__mapped_any(paddr & PAGE_MASK, paddr_next,
433 !e820__mapped_any(paddr & PAGE_MASK, paddr_next,
434 E820_TYPE_RESERVED_KERN))
435 set_pte_safe(pte, __pte(0));
440 * We will re-use the existing mapping.
441 * Xen for example has some special requirements, like mapping
442 * pagetable pages as RO. So assume someone who pre-setup
443 * these mappings are more intelligent.
445 if (!pte_none(*pte)) {
452 pr_info(" pte=%p addr=%lx pte=%016lx\n", pte, paddr,
453 pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL).pte);
455 set_pte_safe(pte, pfn_pte(paddr >> PAGE_SHIFT, prot));
456 paddr_last = (paddr & PAGE_MASK) + PAGE_SIZE;
459 update_page_count(PG_LEVEL_4K, pages);
465 * Create PMD level page table mapping for physical addresses. The virtual
466 * and physical address have to be aligned at this level.
467 * It returns the last physical address mapped.
469 static unsigned long __meminit
470 phys_pmd_init(pmd_t *pmd_page, unsigned long paddr, unsigned long paddr_end,
471 unsigned long page_size_mask, pgprot_t prot)
473 unsigned long pages = 0, paddr_next;
474 unsigned long paddr_last = paddr_end;
476 int i = pmd_index(paddr);
478 for (; i < PTRS_PER_PMD; i++, paddr = paddr_next) {
479 pmd_t *pmd = pmd_page + pmd_index(paddr);
481 pgprot_t new_prot = prot;
483 paddr_next = (paddr & PMD_MASK) + PMD_SIZE;
484 if (paddr >= paddr_end) {
485 if (!after_bootmem &&
486 !e820__mapped_any(paddr & PMD_MASK, paddr_next,
488 !e820__mapped_any(paddr & PMD_MASK, paddr_next,
489 E820_TYPE_RESERVED_KERN))
490 set_pmd_safe(pmd, __pmd(0));
494 if (!pmd_none(*pmd)) {
495 if (!pmd_large(*pmd)) {
496 spin_lock(&init_mm.page_table_lock);
497 pte = (pte_t *)pmd_page_vaddr(*pmd);
498 paddr_last = phys_pte_init(pte, paddr,
500 spin_unlock(&init_mm.page_table_lock);
504 * If we are ok with PG_LEVEL_2M mapping, then we will
505 * use the existing mapping,
507 * Otherwise, we will split the large page mapping but
508 * use the same existing protection bits except for
509 * large page, so that we don't violate Intel's TLB
510 * Application note (317080) which says, while changing
511 * the page sizes, new and old translations should
512 * not differ with respect to page frame and
515 if (page_size_mask & (1 << PG_LEVEL_2M)) {
518 paddr_last = paddr_next;
521 new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
524 if (page_size_mask & (1<<PG_LEVEL_2M)) {
526 spin_lock(&init_mm.page_table_lock);
527 set_pte_safe((pte_t *)pmd,
528 pfn_pte((paddr & PMD_MASK) >> PAGE_SHIFT,
529 __pgprot(pgprot_val(prot) | _PAGE_PSE)));
530 spin_unlock(&init_mm.page_table_lock);
531 paddr_last = paddr_next;
535 pte = alloc_low_page();
536 paddr_last = phys_pte_init(pte, paddr, paddr_end, new_prot);
538 spin_lock(&init_mm.page_table_lock);
539 pmd_populate_kernel_safe(&init_mm, pmd, pte);
540 spin_unlock(&init_mm.page_table_lock);
542 update_page_count(PG_LEVEL_2M, pages);
547 * Create PUD level page table mapping for physical addresses. The virtual
548 * and physical address do not have to be aligned at this level. KASLR can
549 * randomize virtual addresses up to this level.
550 * It returns the last physical address mapped.
552 static unsigned long __meminit
553 phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end,
554 unsigned long page_size_mask)
556 unsigned long pages = 0, paddr_next;
557 unsigned long paddr_last = paddr_end;
558 unsigned long vaddr = (unsigned long)__va(paddr);
559 int i = pud_index(vaddr);
561 for (; i < PTRS_PER_PUD; i++, paddr = paddr_next) {
564 pgprot_t prot = PAGE_KERNEL;
566 vaddr = (unsigned long)__va(paddr);
567 pud = pud_page + pud_index(vaddr);
568 paddr_next = (paddr & PUD_MASK) + PUD_SIZE;
570 if (paddr >= paddr_end) {
571 if (!after_bootmem &&
572 !e820__mapped_any(paddr & PUD_MASK, paddr_next,
574 !e820__mapped_any(paddr & PUD_MASK, paddr_next,
575 E820_TYPE_RESERVED_KERN))
576 set_pud_safe(pud, __pud(0));
580 if (!pud_none(*pud)) {
581 if (!pud_large(*pud)) {
582 pmd = pmd_offset(pud, 0);
583 paddr_last = phys_pmd_init(pmd, paddr,
590 * If we are ok with PG_LEVEL_1G mapping, then we will
591 * use the existing mapping.
593 * Otherwise, we will split the gbpage mapping but use
594 * the same existing protection bits except for large
595 * page, so that we don't violate Intel's TLB
596 * Application note (317080) which says, while changing
597 * the page sizes, new and old translations should
598 * not differ with respect to page frame and
601 if (page_size_mask & (1 << PG_LEVEL_1G)) {
604 paddr_last = paddr_next;
607 prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
610 if (page_size_mask & (1<<PG_LEVEL_1G)) {
612 spin_lock(&init_mm.page_table_lock);
613 set_pte_safe((pte_t *)pud,
614 pfn_pte((paddr & PUD_MASK) >> PAGE_SHIFT,
616 spin_unlock(&init_mm.page_table_lock);
617 paddr_last = paddr_next;
621 pmd = alloc_low_page();
622 paddr_last = phys_pmd_init(pmd, paddr, paddr_end,
623 page_size_mask, prot);
625 spin_lock(&init_mm.page_table_lock);
626 pud_populate_safe(&init_mm, pud, pmd);
627 spin_unlock(&init_mm.page_table_lock);
630 update_page_count(PG_LEVEL_1G, pages);
635 static unsigned long __meminit
636 phys_p4d_init(p4d_t *p4d_page, unsigned long paddr, unsigned long paddr_end,
637 unsigned long page_size_mask)
639 unsigned long paddr_next, paddr_last = paddr_end;
640 unsigned long vaddr = (unsigned long)__va(paddr);
641 int i = p4d_index(vaddr);
643 if (!pgtable_l5_enabled())
644 return phys_pud_init((pud_t *) p4d_page, paddr, paddr_end, page_size_mask);
646 for (; i < PTRS_PER_P4D; i++, paddr = paddr_next) {
650 vaddr = (unsigned long)__va(paddr);
651 p4d = p4d_page + p4d_index(vaddr);
652 paddr_next = (paddr & P4D_MASK) + P4D_SIZE;
654 if (paddr >= paddr_end) {
655 if (!after_bootmem &&
656 !e820__mapped_any(paddr & P4D_MASK, paddr_next,
658 !e820__mapped_any(paddr & P4D_MASK, paddr_next,
659 E820_TYPE_RESERVED_KERN))
660 set_p4d_safe(p4d, __p4d(0));
664 if (!p4d_none(*p4d)) {
665 pud = pud_offset(p4d, 0);
666 paddr_last = phys_pud_init(pud, paddr,
672 pud = alloc_low_page();
673 paddr_last = phys_pud_init(pud, paddr, paddr_end,
676 spin_lock(&init_mm.page_table_lock);
677 p4d_populate_safe(&init_mm, p4d, pud);
678 spin_unlock(&init_mm.page_table_lock);
685 * Create page table mapping for the physical memory for specific physical
686 * addresses. The virtual and physical addresses have to be aligned on PMD level
687 * down. It returns the last physical address mapped.
689 unsigned long __meminit
690 kernel_physical_mapping_init(unsigned long paddr_start,
691 unsigned long paddr_end,
692 unsigned long page_size_mask)
694 bool pgd_changed = false;
695 unsigned long vaddr, vaddr_start, vaddr_end, vaddr_next, paddr_last;
697 paddr_last = paddr_end;
698 vaddr = (unsigned long)__va(paddr_start);
699 vaddr_end = (unsigned long)__va(paddr_end);
702 for (; vaddr < vaddr_end; vaddr = vaddr_next) {
703 pgd_t *pgd = pgd_offset_k(vaddr);
706 vaddr_next = (vaddr & PGDIR_MASK) + PGDIR_SIZE;
709 p4d = (p4d_t *)pgd_page_vaddr(*pgd);
710 paddr_last = phys_p4d_init(p4d, __pa(vaddr),
716 p4d = alloc_low_page();
717 paddr_last = phys_p4d_init(p4d, __pa(vaddr), __pa(vaddr_end),
720 spin_lock(&init_mm.page_table_lock);
721 if (pgtable_l5_enabled())
722 pgd_populate_safe(&init_mm, pgd, p4d);
724 p4d_populate_safe(&init_mm, p4d_offset(pgd, vaddr), (pud_t *) p4d);
725 spin_unlock(&init_mm.page_table_lock);
730 sync_global_pgds(vaddr_start, vaddr_end - 1);
736 void __init initmem_init(void)
738 memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
742 void __init paging_init(void)
744 sparse_memory_present_with_active_regions(MAX_NUMNODES);
748 * clear the default setting with node 0
749 * note: don't use nodes_clear here, that is really clearing when
750 * numa support is not compiled in, and later node_set_state
751 * will not set it back.
753 node_clear_state(0, N_MEMORY);
754 if (N_MEMORY != N_NORMAL_MEMORY)
755 node_clear_state(0, N_NORMAL_MEMORY);
761 * Memory hotplug specific functions
763 #ifdef CONFIG_MEMORY_HOTPLUG
765 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
768 static void update_end_of_memory_vars(u64 start, u64 size)
770 unsigned long end_pfn = PFN_UP(start + size);
772 if (end_pfn > max_pfn) {
774 max_low_pfn = end_pfn;
775 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
779 int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
780 struct vmem_altmap *altmap, bool want_memblock)
784 ret = __add_pages(nid, start_pfn, nr_pages, altmap, want_memblock);
787 /* update max_pfn, max_low_pfn and high_memory */
788 update_end_of_memory_vars(start_pfn << PAGE_SHIFT,
789 nr_pages << PAGE_SHIFT);
794 int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
797 unsigned long start_pfn = start >> PAGE_SHIFT;
798 unsigned long nr_pages = size >> PAGE_SHIFT;
800 init_memory_mapping(start, start + size);
802 return add_pages(nid, start_pfn, nr_pages, altmap, want_memblock);
805 #define PAGE_INUSE 0xFD
807 static void __meminit free_pagetable(struct page *page, int order)
810 unsigned int nr_pages = 1 << order;
812 /* bootmem page has reserved flag */
813 if (PageReserved(page)) {
814 __ClearPageReserved(page);
816 magic = (unsigned long)page->freelist;
817 if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
819 put_page_bootmem(page++);
822 free_reserved_page(page++);
824 free_pages((unsigned long)page_address(page), order);
827 static void __meminit free_hugepage_table(struct page *page,
828 struct vmem_altmap *altmap)
831 vmem_altmap_free(altmap, PMD_SIZE / PAGE_SIZE);
833 free_pagetable(page, get_order(PMD_SIZE));
836 static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
841 for (i = 0; i < PTRS_PER_PTE; i++) {
847 /* free a pte talbe */
848 free_pagetable(pmd_page(*pmd), 0);
849 spin_lock(&init_mm.page_table_lock);
851 spin_unlock(&init_mm.page_table_lock);
854 static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
859 for (i = 0; i < PTRS_PER_PMD; i++) {
865 /* free a pmd talbe */
866 free_pagetable(pud_page(*pud), 0);
867 spin_lock(&init_mm.page_table_lock);
869 spin_unlock(&init_mm.page_table_lock);
872 static void __meminit free_pud_table(pud_t *pud_start, p4d_t *p4d)
877 for (i = 0; i < PTRS_PER_PUD; i++) {
883 /* free a pud talbe */
884 free_pagetable(p4d_page(*p4d), 0);
885 spin_lock(&init_mm.page_table_lock);
887 spin_unlock(&init_mm.page_table_lock);
890 static void __meminit
891 remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
894 unsigned long next, pages = 0;
897 phys_addr_t phys_addr;
899 pte = pte_start + pte_index(addr);
900 for (; addr < end; addr = next, pte++) {
901 next = (addr + PAGE_SIZE) & PAGE_MASK;
905 if (!pte_present(*pte))
909 * We mapped [0,1G) memory as identity mapping when
910 * initializing, in arch/x86/kernel/head_64.S. These
911 * pagetables cannot be removed.
913 phys_addr = pte_val(*pte) + (addr & PAGE_MASK);
914 if (phys_addr < (phys_addr_t)0x40000000)
917 if (PAGE_ALIGNED(addr) && PAGE_ALIGNED(next)) {
919 * Do not free direct mapping pages since they were
920 * freed when offlining, or simplely not in use.
923 free_pagetable(pte_page(*pte), 0);
925 spin_lock(&init_mm.page_table_lock);
926 pte_clear(&init_mm, addr, pte);
927 spin_unlock(&init_mm.page_table_lock);
929 /* For non-direct mapping, pages means nothing. */
933 * If we are here, we are freeing vmemmap pages since
934 * direct mapped memory ranges to be freed are aligned.
936 * If we are not removing the whole page, it means
937 * other page structs in this page are being used and
938 * we canot remove them. So fill the unused page_structs
939 * with 0xFD, and remove the page when it is wholly
942 memset((void *)addr, PAGE_INUSE, next - addr);
944 page_addr = page_address(pte_page(*pte));
945 if (!memchr_inv(page_addr, PAGE_INUSE, PAGE_SIZE)) {
946 free_pagetable(pte_page(*pte), 0);
948 spin_lock(&init_mm.page_table_lock);
949 pte_clear(&init_mm, addr, pte);
950 spin_unlock(&init_mm.page_table_lock);
955 /* Call free_pte_table() in remove_pmd_table(). */
958 update_page_count(PG_LEVEL_4K, -pages);
961 static void __meminit
962 remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
963 bool direct, struct vmem_altmap *altmap)
965 unsigned long next, pages = 0;
970 pmd = pmd_start + pmd_index(addr);
971 for (; addr < end; addr = next, pmd++) {
972 next = pmd_addr_end(addr, end);
974 if (!pmd_present(*pmd))
977 if (pmd_large(*pmd)) {
978 if (IS_ALIGNED(addr, PMD_SIZE) &&
979 IS_ALIGNED(next, PMD_SIZE)) {
981 free_hugepage_table(pmd_page(*pmd),
984 spin_lock(&init_mm.page_table_lock);
986 spin_unlock(&init_mm.page_table_lock);
989 /* If here, we are freeing vmemmap pages. */
990 memset((void *)addr, PAGE_INUSE, next - addr);
992 page_addr = page_address(pmd_page(*pmd));
993 if (!memchr_inv(page_addr, PAGE_INUSE,
995 free_hugepage_table(pmd_page(*pmd),
998 spin_lock(&init_mm.page_table_lock);
1000 spin_unlock(&init_mm.page_table_lock);
1007 pte_base = (pte_t *)pmd_page_vaddr(*pmd);
1008 remove_pte_table(pte_base, addr, next, direct);
1009 free_pte_table(pte_base, pmd);
1012 /* Call free_pmd_table() in remove_pud_table(). */
1014 update_page_count(PG_LEVEL_2M, -pages);
1017 static void __meminit
1018 remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
1019 struct vmem_altmap *altmap, bool direct)
1021 unsigned long next, pages = 0;
1026 pud = pud_start + pud_index(addr);
1027 for (; addr < end; addr = next, pud++) {
1028 next = pud_addr_end(addr, end);
1030 if (!pud_present(*pud))
1033 if (pud_large(*pud)) {
1034 if (IS_ALIGNED(addr, PUD_SIZE) &&
1035 IS_ALIGNED(next, PUD_SIZE)) {
1037 free_pagetable(pud_page(*pud),
1038 get_order(PUD_SIZE));
1040 spin_lock(&init_mm.page_table_lock);
1042 spin_unlock(&init_mm.page_table_lock);
1045 /* If here, we are freeing vmemmap pages. */
1046 memset((void *)addr, PAGE_INUSE, next - addr);
1048 page_addr = page_address(pud_page(*pud));
1049 if (!memchr_inv(page_addr, PAGE_INUSE,
1051 free_pagetable(pud_page(*pud),
1052 get_order(PUD_SIZE));
1054 spin_lock(&init_mm.page_table_lock);
1056 spin_unlock(&init_mm.page_table_lock);
1063 pmd_base = pmd_offset(pud, 0);
1064 remove_pmd_table(pmd_base, addr, next, direct, altmap);
1065 free_pmd_table(pmd_base, pud);
1069 update_page_count(PG_LEVEL_1G, -pages);
1072 static void __meminit
1073 remove_p4d_table(p4d_t *p4d_start, unsigned long addr, unsigned long end,
1074 struct vmem_altmap *altmap, bool direct)
1076 unsigned long next, pages = 0;
1080 p4d = p4d_start + p4d_index(addr);
1081 for (; addr < end; addr = next, p4d++) {
1082 next = p4d_addr_end(addr, end);
1084 if (!p4d_present(*p4d))
1087 BUILD_BUG_ON(p4d_large(*p4d));
1089 pud_base = pud_offset(p4d, 0);
1090 remove_pud_table(pud_base, addr, next, altmap, direct);
1092 * For 4-level page tables we do not want to free PUDs, but in the
1093 * 5-level case we should free them. This code will have to change
1094 * to adapt for boot-time switching between 4 and 5 level page tables.
1096 if (pgtable_l5_enabled())
1097 free_pud_table(pud_base, p4d);
1101 update_page_count(PG_LEVEL_512G, -pages);
1104 /* start and end are both virtual address. */
1105 static void __meminit
1106 remove_pagetable(unsigned long start, unsigned long end, bool direct,
1107 struct vmem_altmap *altmap)
1114 for (addr = start; addr < end; addr = next) {
1115 next = pgd_addr_end(addr, end);
1117 pgd = pgd_offset_k(addr);
1118 if (!pgd_present(*pgd))
1121 p4d = p4d_offset(pgd, 0);
1122 remove_p4d_table(p4d, addr, next, altmap, direct);
1128 void __ref vmemmap_free(unsigned long start, unsigned long end,
1129 struct vmem_altmap *altmap)
1131 remove_pagetable(start, end, false, altmap);
1134 #ifdef CONFIG_MEMORY_HOTREMOVE
1135 static void __meminit
1136 kernel_physical_mapping_remove(unsigned long start, unsigned long end)
1138 start = (unsigned long)__va(start);
1139 end = (unsigned long)__va(end);
1141 remove_pagetable(start, end, true, NULL);
1144 int __ref arch_remove_memory(int nid, u64 start, u64 size,
1145 struct vmem_altmap *altmap)
1147 unsigned long start_pfn = start >> PAGE_SHIFT;
1148 unsigned long nr_pages = size >> PAGE_SHIFT;
1149 struct page *page = pfn_to_page(start_pfn);
1153 /* With altmap the first mapped page is offset from @start */
1155 page += vmem_altmap_offset(altmap);
1156 zone = page_zone(page);
1157 ret = __remove_pages(zone, start_pfn, nr_pages, altmap);
1159 kernel_physical_mapping_remove(start, start + size);
1164 #endif /* CONFIG_MEMORY_HOTPLUG */
1166 static struct kcore_list kcore_vsyscall;
1168 static void __init register_page_bootmem_info(void)
1173 for_each_online_node(i)
1174 register_page_bootmem_info_node(NODE_DATA(i));
1178 void __init mem_init(void)
1182 /* clear_bss() already clear the empty_zero_page */
1184 /* this will put all memory onto the freelists */
1185 memblock_free_all();
1187 x86_init.hyper.init_after_bootmem();
1190 * Must be done after boot memory is put on freelist, because here we
1191 * might set fields in deferred struct pages that have not yet been
1192 * initialized, and memblock_free_all() initializes all the reserved
1193 * deferred pages for us.
1195 register_page_bootmem_info();
1197 /* Register memory areas for /proc/kcore */
1198 if (get_gate_vma(&init_mm))
1199 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR, PAGE_SIZE, KCORE_USER);
1201 mem_init_print_info(NULL);
1204 int kernel_set_to_readonly;
1206 void set_kernel_text_rw(void)
1208 unsigned long start = PFN_ALIGN(_text);
1209 unsigned long end = PFN_ALIGN(__stop___ex_table);
1211 if (!kernel_set_to_readonly)
1214 pr_debug("Set kernel text: %lx - %lx for read write\n",
1218 * Make the kernel identity mapping for text RW. Kernel text
1219 * mapping will always be RO. Refer to the comment in
1220 * static_protections() in pageattr.c
1222 set_memory_rw(start, (end - start) >> PAGE_SHIFT);
1225 void set_kernel_text_ro(void)
1227 unsigned long start = PFN_ALIGN(_text);
1228 unsigned long end = PFN_ALIGN(__stop___ex_table);
1230 if (!kernel_set_to_readonly)
1233 pr_debug("Set kernel text: %lx - %lx for read only\n",
1237 * Set the kernel identity mapping for text RO.
1239 set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1242 void mark_rodata_ro(void)
1244 unsigned long start = PFN_ALIGN(_text);
1245 unsigned long rodata_start = PFN_ALIGN(__start_rodata);
1246 unsigned long end = (unsigned long) &__end_rodata_hpage_align;
1247 unsigned long text_end = PFN_ALIGN(&__stop___ex_table);
1248 unsigned long rodata_end = PFN_ALIGN(&__end_rodata);
1249 unsigned long all_end;
1251 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
1252 (end - start) >> 10);
1253 set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1255 kernel_set_to_readonly = 1;
1258 * The rodata/data/bss/brk section (but not the kernel text!)
1259 * should also be not-executable.
1261 * We align all_end to PMD_SIZE because the existing mapping
1262 * is a full PMD. If we would align _brk_end to PAGE_SIZE we
1263 * split the PMD and the reminder between _brk_end and the end
1264 * of the PMD will remain mapped executable.
1266 * Any PMD which was setup after the one which covers _brk_end
1267 * has been zapped already via cleanup_highmem().
1269 all_end = roundup((unsigned long)_brk_end, PMD_SIZE);
1270 set_memory_nx(text_end, (all_end - text_end) >> PAGE_SHIFT);
1272 #ifdef CONFIG_CPA_DEBUG
1273 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
1274 set_memory_rw(start, (end-start) >> PAGE_SHIFT);
1276 printk(KERN_INFO "Testing CPA: again\n");
1277 set_memory_ro(start, (end-start) >> PAGE_SHIFT);
1280 free_kernel_image_pages((void *)text_end, (void *)rodata_start);
1281 free_kernel_image_pages((void *)rodata_end, (void *)_sdata);
1286 int kern_addr_valid(unsigned long addr)
1288 unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
1295 if (above != 0 && above != -1UL)
1298 pgd = pgd_offset_k(addr);
1302 p4d = p4d_offset(pgd, addr);
1306 pud = pud_offset(p4d, addr);
1310 if (pud_large(*pud))
1311 return pfn_valid(pud_pfn(*pud));
1313 pmd = pmd_offset(pud, addr);
1317 if (pmd_large(*pmd))
1318 return pfn_valid(pmd_pfn(*pmd));
1320 pte = pte_offset_kernel(pmd, addr);
1324 return pfn_valid(pte_pfn(*pte));
1328 * Block size is the minimum amount of memory which can be hotplugged or
1329 * hotremoved. It must be power of two and must be equal or larger than
1330 * MIN_MEMORY_BLOCK_SIZE.
1332 #define MAX_BLOCK_SIZE (2UL << 30)
1334 /* Amount of ram needed to start using large blocks */
1335 #define MEM_SIZE_FOR_LARGE_BLOCK (64UL << 30)
1337 /* Adjustable memory block size */
1338 static unsigned long set_memory_block_size;
1339 int __init set_memory_block_size_order(unsigned int order)
1341 unsigned long size = 1UL << order;
1343 if (size > MEM_SIZE_FOR_LARGE_BLOCK || size < MIN_MEMORY_BLOCK_SIZE)
1346 set_memory_block_size = size;
1350 static unsigned long probe_memory_block_size(void)
1352 unsigned long boot_mem_end = max_pfn << PAGE_SHIFT;
1355 /* If memory block size has been set, then use it */
1356 bz = set_memory_block_size;
1360 /* Use regular block if RAM is smaller than MEM_SIZE_FOR_LARGE_BLOCK */
1361 if (boot_mem_end < MEM_SIZE_FOR_LARGE_BLOCK) {
1362 bz = MIN_MEMORY_BLOCK_SIZE;
1366 /* Find the largest allowed block size that aligns to memory end */
1367 for (bz = MAX_BLOCK_SIZE; bz > MIN_MEMORY_BLOCK_SIZE; bz >>= 1) {
1368 if (IS_ALIGNED(boot_mem_end, bz))
1372 pr_info("x86/mm: Memory block size: %ldMB\n", bz >> 20);
1377 static unsigned long memory_block_size_probed;
1378 unsigned long memory_block_size_bytes(void)
1380 if (!memory_block_size_probed)
1381 memory_block_size_probed = probe_memory_block_size();
1383 return memory_block_size_probed;
1386 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1388 * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1390 static long __meminitdata addr_start, addr_end;
1391 static void __meminitdata *p_start, *p_end;
1392 static int __meminitdata node_start;
1394 static int __meminit vmemmap_populate_hugepages(unsigned long start,
1395 unsigned long end, int node, struct vmem_altmap *altmap)
1404 for (addr = start; addr < end; addr = next) {
1405 next = pmd_addr_end(addr, end);
1407 pgd = vmemmap_pgd_populate(addr, node);
1411 p4d = vmemmap_p4d_populate(pgd, addr, node);
1415 pud = vmemmap_pud_populate(p4d, addr, node);
1419 pmd = pmd_offset(pud, addr);
1420 if (pmd_none(*pmd)) {
1424 p = altmap_alloc_block_buf(PMD_SIZE, altmap);
1426 p = vmemmap_alloc_block_buf(PMD_SIZE, node);
1430 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1432 set_pmd(pmd, __pmd(pte_val(entry)));
1434 /* check to see if we have contiguous blocks */
1435 if (p_end != p || node_start != node) {
1437 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1438 addr_start, addr_end-1, p_start, p_end-1, node_start);
1444 addr_end = addr + PMD_SIZE;
1445 p_end = p + PMD_SIZE;
1448 return -ENOMEM; /* no fallback */
1449 } else if (pmd_large(*pmd)) {
1450 vmemmap_verify((pte_t *)pmd, node, addr, next);
1453 if (vmemmap_populate_basepages(addr, next, node))
1459 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
1460 struct vmem_altmap *altmap)
1464 if (boot_cpu_has(X86_FEATURE_PSE))
1465 err = vmemmap_populate_hugepages(start, end, node, altmap);
1467 pr_err_once("%s: no cpu support for altmap allocations\n",
1471 err = vmemmap_populate_basepages(start, end, node);
1473 sync_global_pgds(start, end - 1);
1477 #if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HAVE_BOOTMEM_INFO_NODE)
1478 void register_page_bootmem_memmap(unsigned long section_nr,
1479 struct page *start_page, unsigned long nr_pages)
1481 unsigned long addr = (unsigned long)start_page;
1482 unsigned long end = (unsigned long)(start_page + nr_pages);
1488 unsigned int nr_pmd_pages;
1491 for (; addr < end; addr = next) {
1494 pgd = pgd_offset_k(addr);
1495 if (pgd_none(*pgd)) {
1496 next = (addr + PAGE_SIZE) & PAGE_MASK;
1499 get_page_bootmem(section_nr, pgd_page(*pgd), MIX_SECTION_INFO);
1501 p4d = p4d_offset(pgd, addr);
1502 if (p4d_none(*p4d)) {
1503 next = (addr + PAGE_SIZE) & PAGE_MASK;
1506 get_page_bootmem(section_nr, p4d_page(*p4d), MIX_SECTION_INFO);
1508 pud = pud_offset(p4d, addr);
1509 if (pud_none(*pud)) {
1510 next = (addr + PAGE_SIZE) & PAGE_MASK;
1513 get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO);
1515 if (!boot_cpu_has(X86_FEATURE_PSE)) {
1516 next = (addr + PAGE_SIZE) & PAGE_MASK;
1517 pmd = pmd_offset(pud, addr);
1520 get_page_bootmem(section_nr, pmd_page(*pmd),
1523 pte = pte_offset_kernel(pmd, addr);
1526 get_page_bootmem(section_nr, pte_page(*pte),
1529 next = pmd_addr_end(addr, end);
1531 pmd = pmd_offset(pud, addr);
1535 nr_pmd_pages = 1 << get_order(PMD_SIZE);
1536 page = pmd_page(*pmd);
1537 while (nr_pmd_pages--)
1538 get_page_bootmem(section_nr, page++,
1545 void __meminit vmemmap_populate_print_last(void)
1548 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1549 addr_start, addr_end-1, p_start, p_end-1, node_start);