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v3.15
 
   1/*
   2 *  linux/arch/x86_64/mm/init.c
   3 *
   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>
   7 */
   8
   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>
  17#include <linux/mm.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>
 
  36
  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>
  42#include <asm/dma.h>
  43#include <asm/fixmap.h>
  44#include <asm/e820.h>
  45#include <asm/apic.h>
  46#include <asm/tlb.h>
  47#include <asm/mmu_context.h>
  48#include <asm/proto.h>
  49#include <asm/smp.h>
  50#include <asm/sections.h>
  51#include <asm/kdebug.h>
  52#include <asm/numa.h>
  53#include <asm/cacheflush.h>
  54#include <asm/init.h>
  55#include <asm/uv/uv.h>
  56#include <asm/setup.h>
 
  57
  58#include "mm_internal.h"
  59
  60static void ident_pmd_init(unsigned long pmd_flag, pmd_t *pmd_page,
  61			   unsigned long addr, unsigned long end)
  62{
  63	addr &= PMD_MASK;
  64	for (; addr < end; addr += PMD_SIZE) {
  65		pmd_t *pmd = pmd_page + pmd_index(addr);
  66
  67		if (!pmd_present(*pmd))
  68			set_pmd(pmd, __pmd(addr | pmd_flag));
  69	}
  70}
  71static int ident_pud_init(struct x86_mapping_info *info, pud_t *pud_page,
  72			  unsigned long addr, unsigned long end)
  73{
  74	unsigned long next;
  75
  76	for (; addr < end; addr = next) {
  77		pud_t *pud = pud_page + pud_index(addr);
  78		pmd_t *pmd;
  79
  80		next = (addr & PUD_MASK) + PUD_SIZE;
  81		if (next > end)
  82			next = end;
  83
  84		if (pud_present(*pud)) {
  85			pmd = pmd_offset(pud, 0);
  86			ident_pmd_init(info->pmd_flag, pmd, addr, next);
  87			continue;
  88		}
  89		pmd = (pmd_t *)info->alloc_pgt_page(info->context);
  90		if (!pmd)
  91			return -ENOMEM;
  92		ident_pmd_init(info->pmd_flag, pmd, addr, next);
  93		set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
  94	}
  95
  96	return 0;
  97}
  98
  99int kernel_ident_mapping_init(struct x86_mapping_info *info, pgd_t *pgd_page,
 100			      unsigned long addr, unsigned long end)
 101{
 102	unsigned long next;
 103	int result;
 104	int off = info->kernel_mapping ? pgd_index(__PAGE_OFFSET) : 0;
 105
 106	for (; addr < end; addr = next) {
 107		pgd_t *pgd = pgd_page + pgd_index(addr) + off;
 108		pud_t *pud;
 109
 110		next = (addr & PGDIR_MASK) + PGDIR_SIZE;
 111		if (next > end)
 112			next = end;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 113
 114		if (pgd_present(*pgd)) {
 115			pud = pud_offset(pgd, 0);
 116			result = ident_pud_init(info, pud, addr, next);
 117			if (result)
 118				return result;
 119			continue;
 120		}
 121
 122		pud = (pud_t *)info->alloc_pgt_page(info->context);
 123		if (!pud)
 124			return -ENOMEM;
 125		result = ident_pud_init(info, pud, addr, next);
 126		if (result)
 127			return result;
 128		set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE));
 129	}
 130
 131	return 0;
 132}
 133
 134static int __init parse_direct_gbpages_off(char *arg)
 135{
 136	direct_gbpages = 0;
 137	return 0;
 138}
 139early_param("nogbpages", parse_direct_gbpages_off);
 140
 141static int __init parse_direct_gbpages_on(char *arg)
 142{
 143	direct_gbpages = 1;
 144	return 0;
 145}
 146early_param("gbpages", parse_direct_gbpages_on);
 147
 148/*
 149 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
 150 * physical space so we can cache the place of the first one and move
 151 * around without checking the pgd every time.
 152 */
 153
 154pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP;
 
 
 
 155EXPORT_SYMBOL_GPL(__supported_pte_mask);
 
 
 156
 157int force_personality32;
 158
 159/*
 160 * noexec32=on|off
 161 * Control non executable heap for 32bit processes.
 162 * To control the stack too use noexec=off
 163 *
 164 * on	PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
 165 * off	PROT_READ implies PROT_EXEC
 166 */
 167static int __init nonx32_setup(char *str)
 168{
 169	if (!strcmp(str, "on"))
 170		force_personality32 &= ~READ_IMPLIES_EXEC;
 171	else if (!strcmp(str, "off"))
 172		force_personality32 |= READ_IMPLIES_EXEC;
 173	return 1;
 174}
 175__setup("noexec32=", nonx32_setup);
 176
 177/*
 178 * When memory was added/removed make sure all the processes MM have
 179 * suitable PGD entries in the local PGD level page.
 180 */
 181void sync_global_pgds(unsigned long start, unsigned long end)
 182{
 183	unsigned long address;
 184
 185	for (address = start; address <= end; address += PGDIR_SIZE) {
 186		const pgd_t *pgd_ref = pgd_offset_k(address);
 187		struct page *page;
 188
 
 
 
 
 189		if (pgd_none(*pgd_ref))
 190			continue;
 191
 192		spin_lock(&pgd_lock);
 193		list_for_each_entry(page, &pgd_list, lru) {
 194			pgd_t *pgd;
 195			spinlock_t *pgt_lock;
 196
 197			pgd = (pgd_t *)page_address(page) + pgd_index(address);
 198			/* the pgt_lock only for Xen */
 199			pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
 200			spin_lock(pgt_lock);
 201
 
 
 
 202			if (pgd_none(*pgd))
 203				set_pgd(pgd, *pgd_ref);
 204			else
 205				BUG_ON(pgd_page_vaddr(*pgd)
 206				       != pgd_page_vaddr(*pgd_ref));
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 207
 208			spin_unlock(pgt_lock);
 209		}
 210		spin_unlock(&pgd_lock);
 211	}
 212}
 213
 214/*
 
 
 
 
 
 
 
 
 
 
 
 
 215 * NOTE: This function is marked __ref because it calls __init function
 216 * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
 217 */
 218static __ref void *spp_getpage(void)
 219{
 220	void *ptr;
 221
 222	if (after_bootmem)
 223		ptr = (void *) get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK);
 224	else
 225		ptr = alloc_bootmem_pages(PAGE_SIZE);
 226
 227	if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
 228		panic("set_pte_phys: cannot allocate page data %s\n",
 229			after_bootmem ? "after bootmem" : "");
 230	}
 231
 232	pr_debug("spp_getpage %p\n", ptr);
 233
 234	return ptr;
 235}
 236
 237static pud_t *fill_pud(pgd_t *pgd, unsigned long vaddr)
 238{
 239	if (pgd_none(*pgd)) {
 240		pud_t *pud = (pud_t *)spp_getpage();
 241		pgd_populate(&init_mm, pgd, pud);
 242		if (pud != pud_offset(pgd, 0))
 243			printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n",
 244			       pud, pud_offset(pgd, 0));
 
 
 
 
 
 
 
 
 
 
 
 
 245	}
 246	return pud_offset(pgd, vaddr);
 247}
 248
 249static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr)
 250{
 251	if (pud_none(*pud)) {
 252		pmd_t *pmd = (pmd_t *) spp_getpage();
 253		pud_populate(&init_mm, pud, pmd);
 254		if (pmd != pmd_offset(pud, 0))
 255			printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
 256			       pmd, pmd_offset(pud, 0));
 257	}
 258	return pmd_offset(pud, vaddr);
 259}
 260
 261static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr)
 262{
 263	if (pmd_none(*pmd)) {
 264		pte_t *pte = (pte_t *) spp_getpage();
 265		pmd_populate_kernel(&init_mm, pmd, pte);
 266		if (pte != pte_offset_kernel(pmd, 0))
 267			printk(KERN_ERR "PAGETABLE BUG #02!\n");
 268	}
 269	return pte_offset_kernel(pmd, vaddr);
 270}
 271
 272void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
 273{
 274	pud_t *pud;
 275	pmd_t *pmd;
 276	pte_t *pte;
 277
 278	pud = pud_page + pud_index(vaddr);
 279	pmd = fill_pmd(pud, vaddr);
 280	pte = fill_pte(pmd, vaddr);
 281
 282	set_pte(pte, new_pte);
 283
 284	/*
 285	 * It's enough to flush this one mapping.
 286	 * (PGE mappings get flushed as well)
 287	 */
 288	__flush_tlb_one(vaddr);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 289}
 290
 291void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
 292{
 293	pgd_t *pgd;
 294	pud_t *pud_page;
 295
 296	pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
 297
 298	pgd = pgd_offset_k(vaddr);
 299	if (pgd_none(*pgd)) {
 300		printk(KERN_ERR
 301			"PGD FIXMAP MISSING, it should be setup in head.S!\n");
 302		return;
 303	}
 304	pud_page = (pud_t*)pgd_page_vaddr(*pgd);
 305	set_pte_vaddr_pud(pud_page, vaddr, pteval);
 
 306}
 307
 308pmd_t * __init populate_extra_pmd(unsigned long vaddr)
 309{
 310	pgd_t *pgd;
 
 311	pud_t *pud;
 312
 313	pgd = pgd_offset_k(vaddr);
 314	pud = fill_pud(pgd, vaddr);
 
 315	return fill_pmd(pud, vaddr);
 316}
 317
 318pte_t * __init populate_extra_pte(unsigned long vaddr)
 319{
 320	pmd_t *pmd;
 321
 322	pmd = populate_extra_pmd(vaddr);
 323	return fill_pte(pmd, vaddr);
 324}
 325
 326/*
 327 * Create large page table mappings for a range of physical addresses.
 328 */
 329static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
 330						pgprot_t prot)
 331{
 332	pgd_t *pgd;
 
 333	pud_t *pud;
 334	pmd_t *pmd;
 
 335
 
 
 336	BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
 337	for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
 338		pgd = pgd_offset_k((unsigned long)__va(phys));
 339		if (pgd_none(*pgd)) {
 
 
 
 
 
 
 340			pud = (pud_t *) spp_getpage();
 341			set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE |
 342						_PAGE_USER));
 343		}
 344		pud = pud_offset(pgd, (unsigned long)__va(phys));
 345		if (pud_none(*pud)) {
 346			pmd = (pmd_t *) spp_getpage();
 347			set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
 348						_PAGE_USER));
 349		}
 350		pmd = pmd_offset(pud, phys);
 351		BUG_ON(!pmd_none(*pmd));
 352		set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
 353	}
 354}
 355
 356void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
 357{
 358	__init_extra_mapping(phys, size, PAGE_KERNEL_LARGE);
 359}
 360
 361void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
 362{
 363	__init_extra_mapping(phys, size, PAGE_KERNEL_LARGE_NOCACHE);
 364}
 365
 366/*
 367 * The head.S code sets up the kernel high mapping:
 368 *
 369 *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
 370 *
 371 * phys_base holds the negative offset to the kernel, which is added
 372 * to the compile time generated pmds. This results in invalid pmds up
 373 * to the point where we hit the physaddr 0 mapping.
 374 *
 375 * We limit the mappings to the region from _text to _brk_end.  _brk_end
 376 * is rounded up to the 2MB boundary. This catches the invalid pmds as
 377 * well, as they are located before _text:
 378 */
 379void __init cleanup_highmap(void)
 380{
 381	unsigned long vaddr = __START_KERNEL_map;
 382	unsigned long vaddr_end = __START_KERNEL_map + KERNEL_IMAGE_SIZE;
 383	unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1;
 384	pmd_t *pmd = level2_kernel_pgt;
 385
 386	/*
 387	 * Native path, max_pfn_mapped is not set yet.
 388	 * Xen has valid max_pfn_mapped set in
 389	 *	arch/x86/xen/mmu.c:xen_setup_kernel_pagetable().
 390	 */
 391	if (max_pfn_mapped)
 392		vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT);
 393
 394	for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) {
 395		if (pmd_none(*pmd))
 396			continue;
 397		if (vaddr < (unsigned long) _text || vaddr > end)
 398			set_pmd(pmd, __pmd(0));
 399	}
 400}
 401
 
 
 
 
 402static unsigned long __meminit
 403phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,
 404	      pgprot_t prot)
 405{
 406	unsigned long pages = 0, next;
 407	unsigned long last_map_addr = end;
 
 408	int i;
 409
 410	pte_t *pte = pte_page + pte_index(addr);
 
 411
 412	for (i = pte_index(addr); i < PTRS_PER_PTE; i++, addr = next, pte++) {
 413		next = (addr & PAGE_MASK) + PAGE_SIZE;
 414		if (addr >= end) {
 415			if (!after_bootmem &&
 416			    !e820_any_mapped(addr & PAGE_MASK, next, E820_RAM) &&
 417			    !e820_any_mapped(addr & PAGE_MASK, next, E820_RESERVED_KERN))
 418				set_pte(pte, __pte(0));
 
 
 419			continue;
 420		}
 421
 422		/*
 423		 * We will re-use the existing mapping.
 424		 * Xen for example has some special requirements, like mapping
 425		 * pagetable pages as RO. So assume someone who pre-setup
 426		 * these mappings are more intelligent.
 427		 */
 428		if (pte_val(*pte)) {
 429			if (!after_bootmem)
 430				pages++;
 431			continue;
 432		}
 433
 434		if (0)
 435			printk("   pte=%p addr=%lx pte=%016lx\n",
 436			       pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
 437		pages++;
 438		set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot));
 439		last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
 440	}
 441
 442	update_page_count(PG_LEVEL_4K, pages);
 443
 444	return last_map_addr;
 445}
 446
 
 
 
 
 
 447static unsigned long __meminit
 448phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
 449	      unsigned long page_size_mask, pgprot_t prot)
 450{
 451	unsigned long pages = 0, next;
 452	unsigned long last_map_addr = end;
 453
 454	int i = pmd_index(address);
 455
 456	for (; i < PTRS_PER_PMD; i++, address = next) {
 457		pmd_t *pmd = pmd_page + pmd_index(address);
 458		pte_t *pte;
 459		pgprot_t new_prot = prot;
 460
 461		next = (address & PMD_MASK) + PMD_SIZE;
 462		if (address >= end) {
 463			if (!after_bootmem &&
 464			    !e820_any_mapped(address & PMD_MASK, next, E820_RAM) &&
 465			    !e820_any_mapped(address & PMD_MASK, next, E820_RESERVED_KERN))
 466				set_pmd(pmd, __pmd(0));
 
 
 467			continue;
 468		}
 469
 470		if (pmd_val(*pmd)) {
 471			if (!pmd_large(*pmd)) {
 472				spin_lock(&init_mm.page_table_lock);
 473				pte = (pte_t *)pmd_page_vaddr(*pmd);
 474				last_map_addr = phys_pte_init(pte, address,
 475								end, prot);
 
 476				spin_unlock(&init_mm.page_table_lock);
 477				continue;
 478			}
 479			/*
 480			 * If we are ok with PG_LEVEL_2M mapping, then we will
 481			 * use the existing mapping,
 482			 *
 483			 * Otherwise, we will split the large page mapping but
 484			 * use the same existing protection bits except for
 485			 * large page, so that we don't violate Intel's TLB
 486			 * Application note (317080) which says, while changing
 487			 * the page sizes, new and old translations should
 488			 * not differ with respect to page frame and
 489			 * attributes.
 490			 */
 491			if (page_size_mask & (1 << PG_LEVEL_2M)) {
 492				if (!after_bootmem)
 493					pages++;
 494				last_map_addr = next;
 495				continue;
 496			}
 497			new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
 498		}
 499
 500		if (page_size_mask & (1<<PG_LEVEL_2M)) {
 501			pages++;
 502			spin_lock(&init_mm.page_table_lock);
 503			set_pte((pte_t *)pmd,
 504				pfn_pte((address & PMD_MASK) >> PAGE_SHIFT,
 505					__pgprot(pgprot_val(prot) | _PAGE_PSE)));
 506			spin_unlock(&init_mm.page_table_lock);
 507			last_map_addr = next;
 508			continue;
 509		}
 510
 511		pte = alloc_low_page();
 512		last_map_addr = phys_pte_init(pte, address, end, new_prot);
 513
 514		spin_lock(&init_mm.page_table_lock);
 515		pmd_populate_kernel(&init_mm, pmd, pte);
 516		spin_unlock(&init_mm.page_table_lock);
 517	}
 518	update_page_count(PG_LEVEL_2M, pages);
 519	return last_map_addr;
 520}
 521
 
 
 
 
 
 
 522static unsigned long __meminit
 523phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
 524			 unsigned long page_size_mask)
 525{
 526	unsigned long pages = 0, next;
 527	unsigned long last_map_addr = end;
 528	int i = pud_index(addr);
 
 529
 530	for (; i < PTRS_PER_PUD; i++, addr = next) {
 531		pud_t *pud = pud_page + pud_index(addr);
 532		pmd_t *pmd;
 533		pgprot_t prot = PAGE_KERNEL;
 534
 535		next = (addr & PUD_MASK) + PUD_SIZE;
 536		if (addr >= end) {
 
 
 
 537			if (!after_bootmem &&
 538			    !e820_any_mapped(addr & PUD_MASK, next, E820_RAM) &&
 539			    !e820_any_mapped(addr & PUD_MASK, next, E820_RESERVED_KERN))
 540				set_pud(pud, __pud(0));
 
 
 541			continue;
 542		}
 543
 544		if (pud_val(*pud)) {
 545			if (!pud_large(*pud)) {
 546				pmd = pmd_offset(pud, 0);
 547				last_map_addr = phys_pmd_init(pmd, addr, end,
 548							 page_size_mask, prot);
 549				__flush_tlb_all();
 
 550				continue;
 551			}
 552			/*
 553			 * If we are ok with PG_LEVEL_1G mapping, then we will
 554			 * use the existing mapping.
 555			 *
 556			 * Otherwise, we will split the gbpage mapping but use
 557			 * the same existing protection  bits except for large
 558			 * page, so that we don't violate Intel's TLB
 559			 * Application note (317080) which says, while changing
 560			 * the page sizes, new and old translations should
 561			 * not differ with respect to page frame and
 562			 * attributes.
 563			 */
 564			if (page_size_mask & (1 << PG_LEVEL_1G)) {
 565				if (!after_bootmem)
 566					pages++;
 567				last_map_addr = next;
 568				continue;
 569			}
 570			prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
 571		}
 572
 573		if (page_size_mask & (1<<PG_LEVEL_1G)) {
 574			pages++;
 575			spin_lock(&init_mm.page_table_lock);
 576			set_pte((pte_t *)pud,
 577				pfn_pte((addr & PUD_MASK) >> PAGE_SHIFT,
 578					PAGE_KERNEL_LARGE));
 579			spin_unlock(&init_mm.page_table_lock);
 580			last_map_addr = next;
 581			continue;
 582		}
 583
 584		pmd = alloc_low_page();
 585		last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask,
 586					      prot);
 587
 588		spin_lock(&init_mm.page_table_lock);
 589		pud_populate(&init_mm, pud, pmd);
 590		spin_unlock(&init_mm.page_table_lock);
 591	}
 592	__flush_tlb_all();
 593
 594	update_page_count(PG_LEVEL_1G, pages);
 595
 596	return last_map_addr;
 597}
 598
 599unsigned long __meminit
 600kernel_physical_mapping_init(unsigned long start,
 601			     unsigned long end,
 602			     unsigned long page_size_mask)
 603{
 604	bool pgd_changed = false;
 605	unsigned long next, last_map_addr = end;
 606	unsigned long addr;
 607
 608	start = (unsigned long)__va(start);
 609	end = (unsigned long)__va(end);
 610	addr = start;
 
 
 
 
 611
 612	for (; start < end; start = next) {
 613		pgd_t *pgd = pgd_offset_k(start);
 614		pud_t *pud;
 615
 616		next = (start & PGDIR_MASK) + PGDIR_SIZE;
 
 617
 618		if (pgd_val(*pgd)) {
 619			pud = (pud_t *)pgd_page_vaddr(*pgd);
 620			last_map_addr = phys_pud_init(pud, __pa(start),
 621						 __pa(end), page_size_mask);
 
 
 
 
 
 
 
 
 
 
 
 622			continue;
 623		}
 624
 625		pud = alloc_low_page();
 626		last_map_addr = phys_pud_init(pud, __pa(start), __pa(end),
 627						 page_size_mask);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 628
 629		spin_lock(&init_mm.page_table_lock);
 630		pgd_populate(&init_mm, pgd, pud);
 
 
 
 
 
 631		spin_unlock(&init_mm.page_table_lock);
 632		pgd_changed = true;
 633	}
 634
 635	if (pgd_changed)
 636		sync_global_pgds(addr, end - 1);
 
 
 
 637
 638	__flush_tlb_all();
 639
 640	return last_map_addr;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 641}
 642
 643#ifndef CONFIG_NUMA
 644void __init initmem_init(void)
 645{
 646	memblock_set_node(0, (phys_addr_t)ULLONG_MAX, &memblock.memory, 0);
 647}
 648#endif
 649
 650void __init paging_init(void)
 651{
 652	sparse_memory_present_with_active_regions(MAX_NUMNODES);
 653	sparse_init();
 654
 655	/*
 656	 * clear the default setting with node 0
 657	 * note: don't use nodes_clear here, that is really clearing when
 658	 *	 numa support is not compiled in, and later node_set_state
 659	 *	 will not set it back.
 660	 */
 661	node_clear_state(0, N_MEMORY);
 662	if (N_MEMORY != N_NORMAL_MEMORY)
 663		node_clear_state(0, N_NORMAL_MEMORY);
 664
 665	zone_sizes_init();
 666}
 667
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 668/*
 669 * Memory hotplug specific functions
 670 */
 671#ifdef CONFIG_MEMORY_HOTPLUG
 672/*
 673 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
 674 * updating.
 675 */
 676static void  update_end_of_memory_vars(u64 start, u64 size)
 677{
 678	unsigned long end_pfn = PFN_UP(start + size);
 679
 680	if (end_pfn > max_pfn) {
 681		max_pfn = end_pfn;
 682		max_low_pfn = end_pfn;
 683		high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
 684	}
 685}
 686
 687/*
 688 * Memory is added always to NORMAL zone. This means you will never get
 689 * additional DMA/DMA32 memory.
 690 */
 691int arch_add_memory(int nid, u64 start, u64 size)
 692{
 693	struct pglist_data *pgdat = NODE_DATA(nid);
 694	struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
 695	unsigned long start_pfn = start >> PAGE_SHIFT;
 696	unsigned long nr_pages = size >> PAGE_SHIFT;
 697	int ret;
 698
 699	init_memory_mapping(start, start + size);
 700
 701	ret = __add_pages(nid, zone, start_pfn, nr_pages);
 702	WARN_ON_ONCE(ret);
 703
 704	/* update max_pfn, max_low_pfn and high_memory */
 705	update_end_of_memory_vars(start, size);
 
 706
 707	return ret;
 708}
 709EXPORT_SYMBOL_GPL(arch_add_memory);
 710
 711#define PAGE_INUSE 0xFD
 
 
 
 
 
 
 
 
 
 712
 713static void __meminit free_pagetable(struct page *page, int order)
 714{
 715	unsigned long magic;
 716	unsigned int nr_pages = 1 << order;
 717
 718	/* bootmem page has reserved flag */
 719	if (PageReserved(page)) {
 720		__ClearPageReserved(page);
 721
 722		magic = (unsigned long)page->lru.next;
 723		if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
 724			while (nr_pages--)
 725				put_page_bootmem(page++);
 726		} else
 727			while (nr_pages--)
 728				free_reserved_page(page++);
 729	} else
 730		free_pages((unsigned long)page_address(page), order);
 731}
 732
 
 
 
 
 
 
 
 
 
 733static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
 734{
 735	pte_t *pte;
 736	int i;
 737
 738	for (i = 0; i < PTRS_PER_PTE; i++) {
 739		pte = pte_start + i;
 740		if (pte_val(*pte))
 741			return;
 742	}
 743
 744	/* free a pte talbe */
 745	free_pagetable(pmd_page(*pmd), 0);
 746	spin_lock(&init_mm.page_table_lock);
 747	pmd_clear(pmd);
 748	spin_unlock(&init_mm.page_table_lock);
 749}
 750
 751static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
 752{
 753	pmd_t *pmd;
 754	int i;
 755
 756	for (i = 0; i < PTRS_PER_PMD; i++) {
 757		pmd = pmd_start + i;
 758		if (pmd_val(*pmd))
 759			return;
 760	}
 761
 762	/* free a pmd talbe */
 763	free_pagetable(pud_page(*pud), 0);
 764	spin_lock(&init_mm.page_table_lock);
 765	pud_clear(pud);
 766	spin_unlock(&init_mm.page_table_lock);
 767}
 768
 769/* Return true if pgd is changed, otherwise return false. */
 770static bool __meminit free_pud_table(pud_t *pud_start, pgd_t *pgd)
 771{
 772	pud_t *pud;
 773	int i;
 774
 775	for (i = 0; i < PTRS_PER_PUD; i++) {
 776		pud = pud_start + i;
 777		if (pud_val(*pud))
 778			return false;
 779	}
 780
 781	/* free a pud table */
 782	free_pagetable(pgd_page(*pgd), 0);
 783	spin_lock(&init_mm.page_table_lock);
 784	pgd_clear(pgd);
 785	spin_unlock(&init_mm.page_table_lock);
 786
 787	return true;
 788}
 789
 790static void __meminit
 791remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
 792		 bool direct)
 793{
 794	unsigned long next, pages = 0;
 795	pte_t *pte;
 796	void *page_addr;
 797	phys_addr_t phys_addr;
 798
 799	pte = pte_start + pte_index(addr);
 800	for (; addr < end; addr = next, pte++) {
 801		next = (addr + PAGE_SIZE) & PAGE_MASK;
 802		if (next > end)
 803			next = end;
 804
 805		if (!pte_present(*pte))
 806			continue;
 807
 808		/*
 809		 * We mapped [0,1G) memory as identity mapping when
 810		 * initializing, in arch/x86/kernel/head_64.S. These
 811		 * pagetables cannot be removed.
 812		 */
 813		phys_addr = pte_val(*pte) + (addr & PAGE_MASK);
 814		if (phys_addr < (phys_addr_t)0x40000000)
 815			return;
 816
 817		if (IS_ALIGNED(addr, PAGE_SIZE) &&
 818		    IS_ALIGNED(next, PAGE_SIZE)) {
 819			/*
 820			 * Do not free direct mapping pages since they were
 821			 * freed when offlining, or simplely not in use.
 822			 */
 823			if (!direct)
 824				free_pagetable(pte_page(*pte), 0);
 825
 826			spin_lock(&init_mm.page_table_lock);
 827			pte_clear(&init_mm, addr, pte);
 828			spin_unlock(&init_mm.page_table_lock);
 829
 830			/* For non-direct mapping, pages means nothing. */
 831			pages++;
 832		} else {
 833			/*
 834			 * If we are here, we are freeing vmemmap pages since
 835			 * direct mapped memory ranges to be freed are aligned.
 836			 *
 837			 * If we are not removing the whole page, it means
 838			 * other page structs in this page are being used and
 839			 * we canot remove them. So fill the unused page_structs
 840			 * with 0xFD, and remove the page when it is wholly
 841			 * filled with 0xFD.
 842			 */
 843			memset((void *)addr, PAGE_INUSE, next - addr);
 844
 845			page_addr = page_address(pte_page(*pte));
 846			if (!memchr_inv(page_addr, PAGE_INUSE, PAGE_SIZE)) {
 847				free_pagetable(pte_page(*pte), 0);
 848
 849				spin_lock(&init_mm.page_table_lock);
 850				pte_clear(&init_mm, addr, pte);
 851				spin_unlock(&init_mm.page_table_lock);
 852			}
 853		}
 854	}
 855
 856	/* Call free_pte_table() in remove_pmd_table(). */
 857	flush_tlb_all();
 858	if (direct)
 859		update_page_count(PG_LEVEL_4K, -pages);
 860}
 861
 862static void __meminit
 863remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
 864		 bool direct)
 865{
 866	unsigned long next, pages = 0;
 867	pte_t *pte_base;
 868	pmd_t *pmd;
 869	void *page_addr;
 870
 871	pmd = pmd_start + pmd_index(addr);
 872	for (; addr < end; addr = next, pmd++) {
 873		next = pmd_addr_end(addr, end);
 874
 875		if (!pmd_present(*pmd))
 876			continue;
 877
 878		if (pmd_large(*pmd)) {
 879			if (IS_ALIGNED(addr, PMD_SIZE) &&
 880			    IS_ALIGNED(next, PMD_SIZE)) {
 881				if (!direct)
 882					free_pagetable(pmd_page(*pmd),
 883						       get_order(PMD_SIZE));
 884
 885				spin_lock(&init_mm.page_table_lock);
 886				pmd_clear(pmd);
 887				spin_unlock(&init_mm.page_table_lock);
 888				pages++;
 889			} else {
 890				/* If here, we are freeing vmemmap pages. */
 891				memset((void *)addr, PAGE_INUSE, next - addr);
 892
 893				page_addr = page_address(pmd_page(*pmd));
 894				if (!memchr_inv(page_addr, PAGE_INUSE,
 895						PMD_SIZE)) {
 896					free_pagetable(pmd_page(*pmd),
 897						       get_order(PMD_SIZE));
 898
 899					spin_lock(&init_mm.page_table_lock);
 900					pmd_clear(pmd);
 901					spin_unlock(&init_mm.page_table_lock);
 902				}
 903			}
 904
 905			continue;
 906		}
 907
 908		pte_base = (pte_t *)pmd_page_vaddr(*pmd);
 909		remove_pte_table(pte_base, addr, next, direct);
 910		free_pte_table(pte_base, pmd);
 911	}
 912
 913	/* Call free_pmd_table() in remove_pud_table(). */
 914	if (direct)
 915		update_page_count(PG_LEVEL_2M, -pages);
 916}
 917
 918static void __meminit
 919remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
 920		 bool direct)
 921{
 922	unsigned long next, pages = 0;
 923	pmd_t *pmd_base;
 924	pud_t *pud;
 925	void *page_addr;
 926
 927	pud = pud_start + pud_index(addr);
 928	for (; addr < end; addr = next, pud++) {
 929		next = pud_addr_end(addr, end);
 930
 931		if (!pud_present(*pud))
 932			continue;
 933
 934		if (pud_large(*pud)) {
 935			if (IS_ALIGNED(addr, PUD_SIZE) &&
 936			    IS_ALIGNED(next, PUD_SIZE)) {
 937				if (!direct)
 938					free_pagetable(pud_page(*pud),
 939						       get_order(PUD_SIZE));
 940
 941				spin_lock(&init_mm.page_table_lock);
 942				pud_clear(pud);
 943				spin_unlock(&init_mm.page_table_lock);
 944				pages++;
 945			} else {
 946				/* If here, we are freeing vmemmap pages. */
 947				memset((void *)addr, PAGE_INUSE, next - addr);
 948
 949				page_addr = page_address(pud_page(*pud));
 950				if (!memchr_inv(page_addr, PAGE_INUSE,
 951						PUD_SIZE)) {
 952					free_pagetable(pud_page(*pud),
 953						       get_order(PUD_SIZE));
 954
 955					spin_lock(&init_mm.page_table_lock);
 956					pud_clear(pud);
 957					spin_unlock(&init_mm.page_table_lock);
 958				}
 959			}
 960
 961			continue;
 962		}
 963
 964		pmd_base = (pmd_t *)pud_page_vaddr(*pud);
 965		remove_pmd_table(pmd_base, addr, next, direct);
 966		free_pmd_table(pmd_base, pud);
 967	}
 968
 969	if (direct)
 970		update_page_count(PG_LEVEL_1G, -pages);
 971}
 972
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 973/* start and end are both virtual address. */
 974static void __meminit
 975remove_pagetable(unsigned long start, unsigned long end, bool direct)
 
 976{
 977	unsigned long next;
 
 978	pgd_t *pgd;
 979	pud_t *pud;
 980	bool pgd_changed = false;
 981
 982	for (; start < end; start = next) {
 983		next = pgd_addr_end(start, end);
 984
 985		pgd = pgd_offset_k(start);
 986		if (!pgd_present(*pgd))
 987			continue;
 988
 989		pud = (pud_t *)pgd_page_vaddr(*pgd);
 990		remove_pud_table(pud, start, next, direct);
 991		if (free_pud_table(pud, pgd))
 992			pgd_changed = true;
 993	}
 994
 995	if (pgd_changed)
 996		sync_global_pgds(start, end - 1);
 997
 998	flush_tlb_all();
 999}
1000
1001void __ref vmemmap_free(unsigned long start, unsigned long end)
 
1002{
1003	remove_pagetable(start, end, false);
 
 
 
1004}
1005
1006#ifdef CONFIG_MEMORY_HOTREMOVE
1007static void __meminit
1008kernel_physical_mapping_remove(unsigned long start, unsigned long end)
1009{
1010	start = (unsigned long)__va(start);
1011	end = (unsigned long)__va(end);
1012
1013	remove_pagetable(start, end, true);
1014}
1015
1016int __ref arch_remove_memory(u64 start, u64 size)
1017{
1018	unsigned long start_pfn = start >> PAGE_SHIFT;
1019	unsigned long nr_pages = size >> PAGE_SHIFT;
1020	struct zone *zone;
1021	int ret;
1022
1023	zone = page_zone(pfn_to_page(start_pfn));
1024	kernel_physical_mapping_remove(start, start + size);
1025	ret = __remove_pages(zone, start_pfn, nr_pages);
1026	WARN_ON_ONCE(ret);
1027
1028	return ret;
1029}
1030#endif
1031#endif /* CONFIG_MEMORY_HOTPLUG */
1032
1033static struct kcore_list kcore_vsyscall;
1034
1035static void __init register_page_bootmem_info(void)
1036{
1037#ifdef CONFIG_NUMA
1038	int i;
1039
1040	for_each_online_node(i)
1041		register_page_bootmem_info_node(NODE_DATA(i));
1042#endif
1043}
1044
1045void __init mem_init(void)
 
 
 
 
 
1046{
1047	pci_iommu_alloc();
 
1048
1049	/* clear_bss() already clear the empty_zero_page */
 
 
 
1050
1051	register_page_bootmem_info();
 
 
 
1052
1053	/* this will put all memory onto the freelists */
1054	free_all_bootmem();
1055	after_bootmem = 1;
1056
1057	/* Register memory areas for /proc/kcore */
1058	kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
1059			 VSYSCALL_END - VSYSCALL_START, KCORE_OTHER);
 
 
 
 
 
 
 
 
 
 
 
 
1060
1061	mem_init_print_info(NULL);
1062}
1063
1064#ifdef CONFIG_DEBUG_RODATA
1065const int rodata_test_data = 0xC3;
1066EXPORT_SYMBOL_GPL(rodata_test_data);
1067
1068int kernel_set_to_readonly;
 
 
 
 
 
1069
1070void set_kernel_text_rw(void)
1071{
1072	unsigned long start = PFN_ALIGN(_text);
1073	unsigned long end = PFN_ALIGN(__stop___ex_table);
1074
1075	if (!kernel_set_to_readonly)
1076		return;
1077
1078	pr_debug("Set kernel text: %lx - %lx for read write\n",
1079		 start, end);
 
 
1080
1081	/*
1082	 * Make the kernel identity mapping for text RW. Kernel text
1083	 * mapping will always be RO. Refer to the comment in
1084	 * static_protections() in pageattr.c
 
1085	 */
1086	set_memory_rw(start, (end - start) >> PAGE_SHIFT);
1087}
1088
1089void set_kernel_text_ro(void)
1090{
1091	unsigned long start = PFN_ALIGN(_text);
1092	unsigned long end = PFN_ALIGN(__stop___ex_table);
1093
1094	if (!kernel_set_to_readonly)
1095		return;
 
1096
1097	pr_debug("Set kernel text: %lx - %lx for read only\n",
1098		 start, end);
1099
 
 
 
1100	/*
1101	 * Set the kernel identity mapping for text RO.
 
 
1102	 */
1103	set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1104}
 
 
 
1105
1106void mark_rodata_ro(void)
1107{
1108	unsigned long start = PFN_ALIGN(_text);
1109	unsigned long rodata_start = PFN_ALIGN(__start_rodata);
1110	unsigned long end = (unsigned long) &__end_rodata_hpage_align;
1111	unsigned long text_end = PFN_ALIGN(&__stop___ex_table);
1112	unsigned long rodata_end = PFN_ALIGN(&__end_rodata);
1113	unsigned long all_end = PFN_ALIGN(&_end);
1114
1115	printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
1116	       (end - start) >> 10);
1117	set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1118
1119	kernel_set_to_readonly = 1;
1120
1121	/*
1122	 * The rodata/data/bss/brk section (but not the kernel text!)
1123	 * should also be not-executable.
 
 
 
 
 
 
 
 
1124	 */
1125	set_memory_nx(rodata_start, (all_end - rodata_start) >> PAGE_SHIFT);
 
1126
1127	rodata_test();
1128
1129#ifdef CONFIG_CPA_DEBUG
1130	printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
1131	set_memory_rw(start, (end-start) >> PAGE_SHIFT);
1132
1133	printk(KERN_INFO "Testing CPA: again\n");
1134	set_memory_ro(start, (end-start) >> PAGE_SHIFT);
1135#endif
1136
1137	free_init_pages("unused kernel",
1138			(unsigned long) __va(__pa_symbol(text_end)),
1139			(unsigned long) __va(__pa_symbol(rodata_start)));
1140	free_init_pages("unused kernel",
1141			(unsigned long) __va(__pa_symbol(rodata_end)),
1142			(unsigned long) __va(__pa_symbol(_sdata)));
1143}
1144
1145#endif
1146
1147int kern_addr_valid(unsigned long addr)
1148{
1149	unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
1150	pgd_t *pgd;
1151	pud_t *pud;
1152	pmd_t *pmd;
1153	pte_t *pte;
1154
1155	if (above != 0 && above != -1UL)
1156		return 0;
1157
1158	pgd = pgd_offset_k(addr);
1159	if (pgd_none(*pgd))
1160		return 0;
1161
1162	pud = pud_offset(pgd, addr);
1163	if (pud_none(*pud))
1164		return 0;
1165
1166	if (pud_large(*pud))
1167		return pfn_valid(pud_pfn(*pud));
1168
1169	pmd = pmd_offset(pud, addr);
1170	if (pmd_none(*pmd))
1171		return 0;
1172
1173	if (pmd_large(*pmd))
1174		return pfn_valid(pmd_pfn(*pmd));
1175
1176	pte = pte_offset_kernel(pmd, addr);
1177	if (pte_none(*pte))
1178		return 0;
1179
1180	return pfn_valid(pte_pfn(*pte));
1181}
1182
1183/*
1184 * A pseudo VMA to allow ptrace access for the vsyscall page.  This only
1185 * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
1186 * not need special handling anymore:
1187 */
1188static struct vm_area_struct gate_vma = {
1189	.vm_start	= VSYSCALL_START,
1190	.vm_end		= VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
1191	.vm_page_prot	= PAGE_READONLY_EXEC,
1192	.vm_flags	= VM_READ | VM_EXEC
1193};
1194
1195struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
1196{
1197#ifdef CONFIG_IA32_EMULATION
1198	if (!mm || mm->context.ia32_compat)
1199		return NULL;
1200#endif
1201	return &gate_vma;
1202}
1203
1204int in_gate_area(struct mm_struct *mm, unsigned long addr)
 
 
1205{
1206	struct vm_area_struct *vma = get_gate_vma(mm);
1207
1208	if (!vma)
1209		return 0;
1210
1211	return (addr >= vma->vm_start) && (addr < vma->vm_end);
 
1212}
1213
1214/*
1215 * Use this when you have no reliable mm, typically from interrupt
1216 * context. It is less reliable than using a task's mm and may give
1217 * false positives.
1218 */
1219int in_gate_area_no_mm(unsigned long addr)
1220{
1221	return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
1222}
1223
1224const char *arch_vma_name(struct vm_area_struct *vma)
1225{
1226	if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
1227		return "[vdso]";
1228	if (vma == &gate_vma)
1229		return "[vsyscall]";
1230	return NULL;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1231}
1232
1233#ifdef CONFIG_X86_UV
1234unsigned long memory_block_size_bytes(void)
1235{
1236	if (is_uv_system()) {
1237		printk(KERN_INFO "UV: memory block size 2GB\n");
1238		return 2UL * 1024 * 1024 * 1024;
1239	}
1240	return MIN_MEMORY_BLOCK_SIZE;
1241}
1242#endif
1243
1244#ifdef CONFIG_SPARSEMEM_VMEMMAP
1245/*
1246 * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1247 */
1248static long __meminitdata addr_start, addr_end;
1249static void __meminitdata *p_start, *p_end;
1250static int __meminitdata node_start;
1251
1252static int __meminit vmemmap_populate_hugepages(unsigned long start,
1253						unsigned long end, int node)
1254{
1255	unsigned long addr;
1256	unsigned long next;
1257	pgd_t *pgd;
1258	pud_t *pud;
1259	pmd_t *pmd;
1260
1261	for (addr = start; addr < end; addr = next) {
1262		next = pmd_addr_end(addr, end);
 
1263
1264		pgd = vmemmap_pgd_populate(addr, node);
1265		if (!pgd)
1266			return -ENOMEM;
 
 
 
 
 
 
1267
1268		pud = vmemmap_pud_populate(pgd, addr, node);
1269		if (!pud)
1270			return -ENOMEM;
1271
1272		pmd = pmd_offset(pud, addr);
1273		if (pmd_none(*pmd)) {
1274			void *p;
1275
1276			p = vmemmap_alloc_block_buf(PMD_SIZE, node);
1277			if (p) {
1278				pte_t entry;
1279
1280				entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1281						PAGE_KERNEL_LARGE);
1282				set_pmd(pmd, __pmd(pte_val(entry)));
1283
1284				/* check to see if we have contiguous blocks */
1285				if (p_end != p || node_start != node) {
1286					if (p_start)
1287						printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1288						       addr_start, addr_end-1, p_start, p_end-1, node_start);
1289					addr_start = addr;
1290					node_start = node;
1291					p_start = p;
1292				}
1293
1294				addr_end = addr + PMD_SIZE;
1295				p_end = p + PMD_SIZE;
1296				continue;
1297			}
1298		} else if (pmd_large(*pmd)) {
1299			vmemmap_verify((pte_t *)pmd, node, addr, next);
1300			continue;
1301		}
1302		pr_warn_once("vmemmap: falling back to regular page backing\n");
1303		if (vmemmap_populate_basepages(addr, next, node))
1304			return -ENOMEM;
1305	}
1306	return 0;
 
1307}
1308
1309int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
 
1310{
1311	int err;
1312
1313	if (cpu_has_pse)
1314		err = vmemmap_populate_hugepages(start, end, node);
1315	else
1316		err = vmemmap_populate_basepages(start, end, node);
 
 
 
 
 
 
 
 
 
1317	if (!err)
1318		sync_global_pgds(start, end - 1);
1319	return err;
1320}
1321
1322#if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HAVE_BOOTMEM_INFO_NODE)
1323void register_page_bootmem_memmap(unsigned long section_nr,
1324				  struct page *start_page, unsigned long size)
1325{
1326	unsigned long addr = (unsigned long)start_page;
1327	unsigned long end = (unsigned long)(start_page + size);
1328	unsigned long next;
1329	pgd_t *pgd;
 
1330	pud_t *pud;
1331	pmd_t *pmd;
1332	unsigned int nr_pages;
1333	struct page *page;
1334
1335	for (; addr < end; addr = next) {
1336		pte_t *pte = NULL;
1337
1338		pgd = pgd_offset_k(addr);
1339		if (pgd_none(*pgd)) {
1340			next = (addr + PAGE_SIZE) & PAGE_MASK;
1341			continue;
1342		}
1343		get_page_bootmem(section_nr, pgd_page(*pgd), MIX_SECTION_INFO);
1344
1345		pud = pud_offset(pgd, addr);
 
 
 
 
 
 
 
1346		if (pud_none(*pud)) {
1347			next = (addr + PAGE_SIZE) & PAGE_MASK;
1348			continue;
1349		}
1350		get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO);
1351
1352		if (!cpu_has_pse) {
1353			next = (addr + PAGE_SIZE) & PAGE_MASK;
1354			pmd = pmd_offset(pud, addr);
1355			if (pmd_none(*pmd))
1356				continue;
1357			get_page_bootmem(section_nr, pmd_page(*pmd),
1358					 MIX_SECTION_INFO);
1359
1360			pte = pte_offset_kernel(pmd, addr);
1361			if (pte_none(*pte))
1362				continue;
1363			get_page_bootmem(section_nr, pte_page(*pte),
1364					 SECTION_INFO);
1365		} else {
1366			next = pmd_addr_end(addr, end);
1367
1368			pmd = pmd_offset(pud, addr);
1369			if (pmd_none(*pmd))
1370				continue;
1371
1372			nr_pages = 1 << (get_order(PMD_SIZE));
1373			page = pmd_page(*pmd);
1374			while (nr_pages--)
1375				get_page_bootmem(section_nr, page++,
1376						 SECTION_INFO);
1377		}
1378	}
1379}
1380#endif
1381
1382void __meminit vmemmap_populate_print_last(void)
1383{
1384	if (p_start) {
1385		printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1386			addr_start, addr_end-1, p_start, p_end-1, node_start);
1387		p_start = NULL;
1388		p_end = NULL;
1389		node_start = 0;
1390	}
1391}
1392#endif
v6.8
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  linux/arch/x86_64/mm/init.c
   4 *
   5 *  Copyright (C) 1995  Linus Torvalds
   6 *  Copyright (C) 2000  Pavel Machek <pavel@ucw.cz>
   7 *  Copyright (C) 2002,2003 Andi Kleen <ak@suse.de>
   8 */
   9
  10#include <linux/signal.h>
  11#include <linux/sched.h>
  12#include <linux/kernel.h>
  13#include <linux/errno.h>
  14#include <linux/string.h>
  15#include <linux/types.h>
  16#include <linux/ptrace.h>
  17#include <linux/mman.h>
  18#include <linux/mm.h>
  19#include <linux/swap.h>
  20#include <linux/smp.h>
  21#include <linux/init.h>
  22#include <linux/initrd.h>
  23#include <linux/pagemap.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>
  36#include <linux/bootmem_info.h>
  37
  38#include <asm/processor.h>
  39#include <asm/bios_ebda.h>
  40#include <linux/uaccess.h>
 
  41#include <asm/pgalloc.h>
  42#include <asm/dma.h>
  43#include <asm/fixmap.h>
  44#include <asm/e820/api.h>
  45#include <asm/apic.h>
  46#include <asm/tlb.h>
  47#include <asm/mmu_context.h>
  48#include <asm/proto.h>
  49#include <asm/smp.h>
  50#include <asm/sections.h>
  51#include <asm/kdebug.h>
  52#include <asm/numa.h>
  53#include <asm/set_memory.h>
  54#include <asm/init.h>
  55#include <asm/uv/uv.h>
  56#include <asm/setup.h>
  57#include <asm/ftrace.h>
  58
  59#include "mm_internal.h"
  60
  61#include "ident_map.c"
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  62
  63#define DEFINE_POPULATE(fname, type1, type2, init)		\
  64static inline void fname##_init(struct mm_struct *mm,		\
  65		type1##_t *arg1, type2##_t *arg2, bool init)	\
  66{								\
  67	if (init)						\
  68		fname##_safe(mm, arg1, arg2);			\
  69	else							\
  70		fname(mm, arg1, arg2);				\
  71}
  72
  73DEFINE_POPULATE(p4d_populate, p4d, pud, init)
  74DEFINE_POPULATE(pgd_populate, pgd, p4d, init)
  75DEFINE_POPULATE(pud_populate, pud, pmd, init)
  76DEFINE_POPULATE(pmd_populate_kernel, pmd, pte, init)
  77
  78#define DEFINE_ENTRY(type1, type2, init)			\
  79static inline void set_##type1##_init(type1##_t *arg1,		\
  80			type2##_t arg2, bool init)		\
  81{								\
  82	if (init)						\
  83		set_##type1##_safe(arg1, arg2);			\
  84	else							\
  85		set_##type1(arg1, arg2);			\
  86}
  87
  88DEFINE_ENTRY(p4d, p4d, init)
  89DEFINE_ENTRY(pud, pud, init)
  90DEFINE_ENTRY(pmd, pmd, init)
  91DEFINE_ENTRY(pte, pte, init)
  92
  93static inline pgprot_t prot_sethuge(pgprot_t prot)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  94{
  95	WARN_ON_ONCE(pgprot_val(prot) & _PAGE_PAT);
 
 
 
  96
  97	return __pgprot(pgprot_val(prot) | _PAGE_PSE);
 
 
 
  98}
 
  99
 100/*
 101 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
 102 * physical space so we can cache the place of the first one and move
 103 * around without checking the pgd every time.
 104 */
 105
 106/* Bits supported by the hardware: */
 107pteval_t __supported_pte_mask __read_mostly = ~0;
 108/* Bits allowed in normal kernel mappings: */
 109pteval_t __default_kernel_pte_mask __read_mostly = ~0;
 110EXPORT_SYMBOL_GPL(__supported_pte_mask);
 111/* Used in PAGE_KERNEL_* macros which are reasonably used out-of-tree: */
 112EXPORT_SYMBOL(__default_kernel_pte_mask);
 113
 114int force_personality32;
 115
 116/*
 117 * noexec32=on|off
 118 * Control non executable heap for 32bit processes.
 
 119 *
 120 * on	PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
 121 * off	PROT_READ implies PROT_EXEC
 122 */
 123static int __init nonx32_setup(char *str)
 124{
 125	if (!strcmp(str, "on"))
 126		force_personality32 &= ~READ_IMPLIES_EXEC;
 127	else if (!strcmp(str, "off"))
 128		force_personality32 |= READ_IMPLIES_EXEC;
 129	return 1;
 130}
 131__setup("noexec32=", nonx32_setup);
 132
 133static void sync_global_pgds_l5(unsigned long start, unsigned long end)
 
 
 
 
 134{
 135	unsigned long addr;
 136
 137	for (addr = start; addr <= end; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
 138		const pgd_t *pgd_ref = pgd_offset_k(addr);
 139		struct page *page;
 140
 141		/* Check for overflow */
 142		if (addr < start)
 143			break;
 144
 145		if (pgd_none(*pgd_ref))
 146			continue;
 147
 148		spin_lock(&pgd_lock);
 149		list_for_each_entry(page, &pgd_list, lru) {
 150			pgd_t *pgd;
 151			spinlock_t *pgt_lock;
 152
 153			pgd = (pgd_t *)page_address(page) + pgd_index(addr);
 154			/* the pgt_lock only for Xen */
 155			pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
 156			spin_lock(pgt_lock);
 157
 158			if (!pgd_none(*pgd_ref) && !pgd_none(*pgd))
 159				BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref));
 160
 161			if (pgd_none(*pgd))
 162				set_pgd(pgd, *pgd_ref);
 163
 164			spin_unlock(pgt_lock);
 165		}
 166		spin_unlock(&pgd_lock);
 167	}
 168}
 169
 170static void sync_global_pgds_l4(unsigned long start, unsigned long end)
 171{
 172	unsigned long addr;
 173
 174	for (addr = start; addr <= end; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
 175		pgd_t *pgd_ref = pgd_offset_k(addr);
 176		const p4d_t *p4d_ref;
 177		struct page *page;
 178
 179		/*
 180		 * With folded p4d, pgd_none() is always false, we need to
 181		 * handle synchronization on p4d level.
 182		 */
 183		MAYBE_BUILD_BUG_ON(pgd_none(*pgd_ref));
 184		p4d_ref = p4d_offset(pgd_ref, addr);
 185
 186		if (p4d_none(*p4d_ref))
 187			continue;
 188
 189		spin_lock(&pgd_lock);
 190		list_for_each_entry(page, &pgd_list, lru) {
 191			pgd_t *pgd;
 192			p4d_t *p4d;
 193			spinlock_t *pgt_lock;
 194
 195			pgd = (pgd_t *)page_address(page) + pgd_index(addr);
 196			p4d = p4d_offset(pgd, addr);
 197			/* the pgt_lock only for Xen */
 198			pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
 199			spin_lock(pgt_lock);
 200
 201			if (!p4d_none(*p4d_ref) && !p4d_none(*p4d))
 202				BUG_ON(p4d_pgtable(*p4d)
 203				       != p4d_pgtable(*p4d_ref));
 204
 205			if (p4d_none(*p4d))
 206				set_p4d(p4d, *p4d_ref);
 207
 208			spin_unlock(pgt_lock);
 209		}
 210		spin_unlock(&pgd_lock);
 211	}
 212}
 213
 214/*
 215 * When memory was added make sure all the processes MM have
 216 * suitable PGD entries in the local PGD level page.
 217 */
 218static void sync_global_pgds(unsigned long start, unsigned long end)
 219{
 220	if (pgtable_l5_enabled())
 221		sync_global_pgds_l5(start, end);
 222	else
 223		sync_global_pgds_l4(start, end);
 224}
 225
 226/*
 227 * NOTE: This function is marked __ref because it calls __init function
 228 * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
 229 */
 230static __ref void *spp_getpage(void)
 231{
 232	void *ptr;
 233
 234	if (after_bootmem)
 235		ptr = (void *) get_zeroed_page(GFP_ATOMIC);
 236	else
 237		ptr = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
 238
 239	if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
 240		panic("set_pte_phys: cannot allocate page data %s\n",
 241			after_bootmem ? "after bootmem" : "");
 242	}
 243
 244	pr_debug("spp_getpage %p\n", ptr);
 245
 246	return ptr;
 247}
 248
 249static p4d_t *fill_p4d(pgd_t *pgd, unsigned long vaddr)
 250{
 251	if (pgd_none(*pgd)) {
 252		p4d_t *p4d = (p4d_t *)spp_getpage();
 253		pgd_populate(&init_mm, pgd, p4d);
 254		if (p4d != p4d_offset(pgd, 0))
 255			printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n",
 256			       p4d, p4d_offset(pgd, 0));
 257	}
 258	return p4d_offset(pgd, vaddr);
 259}
 260
 261static pud_t *fill_pud(p4d_t *p4d, unsigned long vaddr)
 262{
 263	if (p4d_none(*p4d)) {
 264		pud_t *pud = (pud_t *)spp_getpage();
 265		p4d_populate(&init_mm, p4d, pud);
 266		if (pud != pud_offset(p4d, 0))
 267			printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
 268			       pud, pud_offset(p4d, 0));
 269	}
 270	return pud_offset(p4d, vaddr);
 271}
 272
 273static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr)
 274{
 275	if (pud_none(*pud)) {
 276		pmd_t *pmd = (pmd_t *) spp_getpage();
 277		pud_populate(&init_mm, pud, pmd);
 278		if (pmd != pmd_offset(pud, 0))
 279			printk(KERN_ERR "PAGETABLE BUG #02! %p <-> %p\n",
 280			       pmd, pmd_offset(pud, 0));
 281	}
 282	return pmd_offset(pud, vaddr);
 283}
 284
 285static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr)
 286{
 287	if (pmd_none(*pmd)) {
 288		pte_t *pte = (pte_t *) spp_getpage();
 289		pmd_populate_kernel(&init_mm, pmd, pte);
 290		if (pte != pte_offset_kernel(pmd, 0))
 291			printk(KERN_ERR "PAGETABLE BUG #03!\n");
 292	}
 293	return pte_offset_kernel(pmd, vaddr);
 294}
 295
 296static void __set_pte_vaddr(pud_t *pud, unsigned long vaddr, pte_t new_pte)
 297{
 298	pmd_t *pmd = fill_pmd(pud, vaddr);
 299	pte_t *pte = fill_pte(pmd, vaddr);
 
 
 
 
 
 300
 301	set_pte(pte, new_pte);
 302
 303	/*
 304	 * It's enough to flush this one mapping.
 305	 * (PGE mappings get flushed as well)
 306	 */
 307	flush_tlb_one_kernel(vaddr);
 308}
 309
 310void set_pte_vaddr_p4d(p4d_t *p4d_page, unsigned long vaddr, pte_t new_pte)
 311{
 312	p4d_t *p4d = p4d_page + p4d_index(vaddr);
 313	pud_t *pud = fill_pud(p4d, vaddr);
 314
 315	__set_pte_vaddr(pud, vaddr, new_pte);
 316}
 317
 318void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
 319{
 320	pud_t *pud = pud_page + pud_index(vaddr);
 321
 322	__set_pte_vaddr(pud, vaddr, new_pte);
 323}
 324
 325void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
 326{
 327	pgd_t *pgd;
 328	p4d_t *p4d_page;
 329
 330	pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
 331
 332	pgd = pgd_offset_k(vaddr);
 333	if (pgd_none(*pgd)) {
 334		printk(KERN_ERR
 335			"PGD FIXMAP MISSING, it should be setup in head.S!\n");
 336		return;
 337	}
 338
 339	p4d_page = p4d_offset(pgd, 0);
 340	set_pte_vaddr_p4d(p4d_page, vaddr, pteval);
 341}
 342
 343pmd_t * __init populate_extra_pmd(unsigned long vaddr)
 344{
 345	pgd_t *pgd;
 346	p4d_t *p4d;
 347	pud_t *pud;
 348
 349	pgd = pgd_offset_k(vaddr);
 350	p4d = fill_p4d(pgd, vaddr);
 351	pud = fill_pud(p4d, vaddr);
 352	return fill_pmd(pud, vaddr);
 353}
 354
 355pte_t * __init populate_extra_pte(unsigned long vaddr)
 356{
 357	pmd_t *pmd;
 358
 359	pmd = populate_extra_pmd(vaddr);
 360	return fill_pte(pmd, vaddr);
 361}
 362
 363/*
 364 * Create large page table mappings for a range of physical addresses.
 365 */
 366static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
 367					enum page_cache_mode cache)
 368{
 369	pgd_t *pgd;
 370	p4d_t *p4d;
 371	pud_t *pud;
 372	pmd_t *pmd;
 373	pgprot_t prot;
 374
 375	pgprot_val(prot) = pgprot_val(PAGE_KERNEL_LARGE) |
 376		protval_4k_2_large(cachemode2protval(cache));
 377	BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
 378	for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
 379		pgd = pgd_offset_k((unsigned long)__va(phys));
 380		if (pgd_none(*pgd)) {
 381			p4d = (p4d_t *) spp_getpage();
 382			set_pgd(pgd, __pgd(__pa(p4d) | _KERNPG_TABLE |
 383						_PAGE_USER));
 384		}
 385		p4d = p4d_offset(pgd, (unsigned long)__va(phys));
 386		if (p4d_none(*p4d)) {
 387			pud = (pud_t *) spp_getpage();
 388			set_p4d(p4d, __p4d(__pa(pud) | _KERNPG_TABLE |
 389						_PAGE_USER));
 390		}
 391		pud = pud_offset(p4d, (unsigned long)__va(phys));
 392		if (pud_none(*pud)) {
 393			pmd = (pmd_t *) spp_getpage();
 394			set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
 395						_PAGE_USER));
 396		}
 397		pmd = pmd_offset(pud, phys);
 398		BUG_ON(!pmd_none(*pmd));
 399		set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
 400	}
 401}
 402
 403void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
 404{
 405	__init_extra_mapping(phys, size, _PAGE_CACHE_MODE_WB);
 406}
 407
 408void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
 409{
 410	__init_extra_mapping(phys, size, _PAGE_CACHE_MODE_UC);
 411}
 412
 413/*
 414 * The head.S code sets up the kernel high mapping:
 415 *
 416 *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
 417 *
 418 * phys_base holds the negative offset to the kernel, which is added
 419 * to the compile time generated pmds. This results in invalid pmds up
 420 * to the point where we hit the physaddr 0 mapping.
 421 *
 422 * We limit the mappings to the region from _text to _brk_end.  _brk_end
 423 * is rounded up to the 2MB boundary. This catches the invalid pmds as
 424 * well, as they are located before _text:
 425 */
 426void __init cleanup_highmap(void)
 427{
 428	unsigned long vaddr = __START_KERNEL_map;
 429	unsigned long vaddr_end = __START_KERNEL_map + KERNEL_IMAGE_SIZE;
 430	unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1;
 431	pmd_t *pmd = level2_kernel_pgt;
 432
 433	/*
 434	 * Native path, max_pfn_mapped is not set yet.
 435	 * Xen has valid max_pfn_mapped set in
 436	 *	arch/x86/xen/mmu.c:xen_setup_kernel_pagetable().
 437	 */
 438	if (max_pfn_mapped)
 439		vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT);
 440
 441	for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) {
 442		if (pmd_none(*pmd))
 443			continue;
 444		if (vaddr < (unsigned long) _text || vaddr > end)
 445			set_pmd(pmd, __pmd(0));
 446	}
 447}
 448
 449/*
 450 * Create PTE level page table mapping for physical addresses.
 451 * It returns the last physical address mapped.
 452 */
 453static unsigned long __meminit
 454phys_pte_init(pte_t *pte_page, unsigned long paddr, unsigned long paddr_end,
 455	      pgprot_t prot, bool init)
 456{
 457	unsigned long pages = 0, paddr_next;
 458	unsigned long paddr_last = paddr_end;
 459	pte_t *pte;
 460	int i;
 461
 462	pte = pte_page + pte_index(paddr);
 463	i = pte_index(paddr);
 464
 465	for (; i < PTRS_PER_PTE; i++, paddr = paddr_next, pte++) {
 466		paddr_next = (paddr & PAGE_MASK) + PAGE_SIZE;
 467		if (paddr >= paddr_end) {
 468			if (!after_bootmem &&
 469			    !e820__mapped_any(paddr & PAGE_MASK, paddr_next,
 470					     E820_TYPE_RAM) &&
 471			    !e820__mapped_any(paddr & PAGE_MASK, paddr_next,
 472					     E820_TYPE_RESERVED_KERN))
 473				set_pte_init(pte, __pte(0), init);
 474			continue;
 475		}
 476
 477		/*
 478		 * We will re-use the existing mapping.
 479		 * Xen for example has some special requirements, like mapping
 480		 * pagetable pages as RO. So assume someone who pre-setup
 481		 * these mappings are more intelligent.
 482		 */
 483		if (!pte_none(*pte)) {
 484			if (!after_bootmem)
 485				pages++;
 486			continue;
 487		}
 488
 489		if (0)
 490			pr_info("   pte=%p addr=%lx pte=%016lx\n", pte, paddr,
 491				pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL).pte);
 492		pages++;
 493		set_pte_init(pte, pfn_pte(paddr >> PAGE_SHIFT, prot), init);
 494		paddr_last = (paddr & PAGE_MASK) + PAGE_SIZE;
 495	}
 496
 497	update_page_count(PG_LEVEL_4K, pages);
 498
 499	return paddr_last;
 500}
 501
 502/*
 503 * Create PMD level page table mapping for physical addresses. The virtual
 504 * and physical address have to be aligned at this level.
 505 * It returns the last physical address mapped.
 506 */
 507static unsigned long __meminit
 508phys_pmd_init(pmd_t *pmd_page, unsigned long paddr, unsigned long paddr_end,
 509	      unsigned long page_size_mask, pgprot_t prot, bool init)
 510{
 511	unsigned long pages = 0, paddr_next;
 512	unsigned long paddr_last = paddr_end;
 513
 514	int i = pmd_index(paddr);
 515
 516	for (; i < PTRS_PER_PMD; i++, paddr = paddr_next) {
 517		pmd_t *pmd = pmd_page + pmd_index(paddr);
 518		pte_t *pte;
 519		pgprot_t new_prot = prot;
 520
 521		paddr_next = (paddr & PMD_MASK) + PMD_SIZE;
 522		if (paddr >= paddr_end) {
 523			if (!after_bootmem &&
 524			    !e820__mapped_any(paddr & PMD_MASK, paddr_next,
 525					     E820_TYPE_RAM) &&
 526			    !e820__mapped_any(paddr & PMD_MASK, paddr_next,
 527					     E820_TYPE_RESERVED_KERN))
 528				set_pmd_init(pmd, __pmd(0), init);
 529			continue;
 530		}
 531
 532		if (!pmd_none(*pmd)) {
 533			if (!pmd_large(*pmd)) {
 534				spin_lock(&init_mm.page_table_lock);
 535				pte = (pte_t *)pmd_page_vaddr(*pmd);
 536				paddr_last = phys_pte_init(pte, paddr,
 537							   paddr_end, prot,
 538							   init);
 539				spin_unlock(&init_mm.page_table_lock);
 540				continue;
 541			}
 542			/*
 543			 * If we are ok with PG_LEVEL_2M mapping, then we will
 544			 * use the existing mapping,
 545			 *
 546			 * Otherwise, we will split the large page mapping but
 547			 * use the same existing protection bits except for
 548			 * large page, so that we don't violate Intel's TLB
 549			 * Application note (317080) which says, while changing
 550			 * the page sizes, new and old translations should
 551			 * not differ with respect to page frame and
 552			 * attributes.
 553			 */
 554			if (page_size_mask & (1 << PG_LEVEL_2M)) {
 555				if (!after_bootmem)
 556					pages++;
 557				paddr_last = paddr_next;
 558				continue;
 559			}
 560			new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
 561		}
 562
 563		if (page_size_mask & (1<<PG_LEVEL_2M)) {
 564			pages++;
 565			spin_lock(&init_mm.page_table_lock);
 566			set_pmd_init(pmd,
 567				     pfn_pmd(paddr >> PAGE_SHIFT, prot_sethuge(prot)),
 568				     init);
 569			spin_unlock(&init_mm.page_table_lock);
 570			paddr_last = paddr_next;
 571			continue;
 572		}
 573
 574		pte = alloc_low_page();
 575		paddr_last = phys_pte_init(pte, paddr, paddr_end, new_prot, init);
 576
 577		spin_lock(&init_mm.page_table_lock);
 578		pmd_populate_kernel_init(&init_mm, pmd, pte, init);
 579		spin_unlock(&init_mm.page_table_lock);
 580	}
 581	update_page_count(PG_LEVEL_2M, pages);
 582	return paddr_last;
 583}
 584
 585/*
 586 * Create PUD level page table mapping for physical addresses. The virtual
 587 * and physical address do not have to be aligned at this level. KASLR can
 588 * randomize virtual addresses up to this level.
 589 * It returns the last physical address mapped.
 590 */
 591static unsigned long __meminit
 592phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end,
 593	      unsigned long page_size_mask, pgprot_t _prot, bool init)
 594{
 595	unsigned long pages = 0, paddr_next;
 596	unsigned long paddr_last = paddr_end;
 597	unsigned long vaddr = (unsigned long)__va(paddr);
 598	int i = pud_index(vaddr);
 599
 600	for (; i < PTRS_PER_PUD; i++, paddr = paddr_next) {
 601		pud_t *pud;
 602		pmd_t *pmd;
 603		pgprot_t prot = _prot;
 604
 605		vaddr = (unsigned long)__va(paddr);
 606		pud = pud_page + pud_index(vaddr);
 607		paddr_next = (paddr & PUD_MASK) + PUD_SIZE;
 608
 609		if (paddr >= paddr_end) {
 610			if (!after_bootmem &&
 611			    !e820__mapped_any(paddr & PUD_MASK, paddr_next,
 612					     E820_TYPE_RAM) &&
 613			    !e820__mapped_any(paddr & PUD_MASK, paddr_next,
 614					     E820_TYPE_RESERVED_KERN))
 615				set_pud_init(pud, __pud(0), init);
 616			continue;
 617		}
 618
 619		if (!pud_none(*pud)) {
 620			if (!pud_large(*pud)) {
 621				pmd = pmd_offset(pud, 0);
 622				paddr_last = phys_pmd_init(pmd, paddr,
 623							   paddr_end,
 624							   page_size_mask,
 625							   prot, init);
 626				continue;
 627			}
 628			/*
 629			 * If we are ok with PG_LEVEL_1G mapping, then we will
 630			 * use the existing mapping.
 631			 *
 632			 * Otherwise, we will split the gbpage mapping but use
 633			 * the same existing protection  bits except for large
 634			 * page, so that we don't violate Intel's TLB
 635			 * Application note (317080) which says, while changing
 636			 * the page sizes, new and old translations should
 637			 * not differ with respect to page frame and
 638			 * attributes.
 639			 */
 640			if (page_size_mask & (1 << PG_LEVEL_1G)) {
 641				if (!after_bootmem)
 642					pages++;
 643				paddr_last = paddr_next;
 644				continue;
 645			}
 646			prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
 647		}
 648
 649		if (page_size_mask & (1<<PG_LEVEL_1G)) {
 650			pages++;
 651			spin_lock(&init_mm.page_table_lock);
 652			set_pud_init(pud,
 653				     pfn_pud(paddr >> PAGE_SHIFT, prot_sethuge(prot)),
 654				     init);
 655			spin_unlock(&init_mm.page_table_lock);
 656			paddr_last = paddr_next;
 657			continue;
 658		}
 659
 660		pmd = alloc_low_page();
 661		paddr_last = phys_pmd_init(pmd, paddr, paddr_end,
 662					   page_size_mask, prot, init);
 663
 664		spin_lock(&init_mm.page_table_lock);
 665		pud_populate_init(&init_mm, pud, pmd, init);
 666		spin_unlock(&init_mm.page_table_lock);
 667	}
 
 668
 669	update_page_count(PG_LEVEL_1G, pages);
 670
 671	return paddr_last;
 672}
 673
 674static unsigned long __meminit
 675phys_p4d_init(p4d_t *p4d_page, unsigned long paddr, unsigned long paddr_end,
 676	      unsigned long page_size_mask, pgprot_t prot, bool init)
 
 677{
 678	unsigned long vaddr, vaddr_end, vaddr_next, paddr_next, paddr_last;
 
 
 679
 680	paddr_last = paddr_end;
 681	vaddr = (unsigned long)__va(paddr);
 682	vaddr_end = (unsigned long)__va(paddr_end);
 683
 684	if (!pgtable_l5_enabled())
 685		return phys_pud_init((pud_t *) p4d_page, paddr, paddr_end,
 686				     page_size_mask, prot, init);
 687
 688	for (; vaddr < vaddr_end; vaddr = vaddr_next) {
 689		p4d_t *p4d = p4d_page + p4d_index(vaddr);
 690		pud_t *pud;
 691
 692		vaddr_next = (vaddr & P4D_MASK) + P4D_SIZE;
 693		paddr = __pa(vaddr);
 694
 695		if (paddr >= paddr_end) {
 696			paddr_next = __pa(vaddr_next);
 697			if (!after_bootmem &&
 698			    !e820__mapped_any(paddr & P4D_MASK, paddr_next,
 699					     E820_TYPE_RAM) &&
 700			    !e820__mapped_any(paddr & P4D_MASK, paddr_next,
 701					     E820_TYPE_RESERVED_KERN))
 702				set_p4d_init(p4d, __p4d(0), init);
 703			continue;
 704		}
 705
 706		if (!p4d_none(*p4d)) {
 707			pud = pud_offset(p4d, 0);
 708			paddr_last = phys_pud_init(pud, paddr, __pa(vaddr_end),
 709					page_size_mask, prot, init);
 710			continue;
 711		}
 712
 713		pud = alloc_low_page();
 714		paddr_last = phys_pud_init(pud, paddr, __pa(vaddr_end),
 715					   page_size_mask, prot, init);
 716
 717		spin_lock(&init_mm.page_table_lock);
 718		p4d_populate_init(&init_mm, p4d, pud, init);
 719		spin_unlock(&init_mm.page_table_lock);
 720	}
 721
 722	return paddr_last;
 723}
 724
 725static unsigned long __meminit
 726__kernel_physical_mapping_init(unsigned long paddr_start,
 727			       unsigned long paddr_end,
 728			       unsigned long page_size_mask,
 729			       pgprot_t prot, bool init)
 730{
 731	bool pgd_changed = false;
 732	unsigned long vaddr, vaddr_start, vaddr_end, vaddr_next, paddr_last;
 733
 734	paddr_last = paddr_end;
 735	vaddr = (unsigned long)__va(paddr_start);
 736	vaddr_end = (unsigned long)__va(paddr_end);
 737	vaddr_start = vaddr;
 738
 739	for (; vaddr < vaddr_end; vaddr = vaddr_next) {
 740		pgd_t *pgd = pgd_offset_k(vaddr);
 741		p4d_t *p4d;
 742
 743		vaddr_next = (vaddr & PGDIR_MASK) + PGDIR_SIZE;
 744
 745		if (pgd_val(*pgd)) {
 746			p4d = (p4d_t *)pgd_page_vaddr(*pgd);
 747			paddr_last = phys_p4d_init(p4d, __pa(vaddr),
 748						   __pa(vaddr_end),
 749						   page_size_mask,
 750						   prot, init);
 751			continue;
 752		}
 753
 754		p4d = alloc_low_page();
 755		paddr_last = phys_p4d_init(p4d, __pa(vaddr), __pa(vaddr_end),
 756					   page_size_mask, prot, init);
 757
 758		spin_lock(&init_mm.page_table_lock);
 759		if (pgtable_l5_enabled())
 760			pgd_populate_init(&init_mm, pgd, p4d, init);
 761		else
 762			p4d_populate_init(&init_mm, p4d_offset(pgd, vaddr),
 763					  (pud_t *) p4d, init);
 764
 765		spin_unlock(&init_mm.page_table_lock);
 766		pgd_changed = true;
 767	}
 768
 769	if (pgd_changed)
 770		sync_global_pgds(vaddr_start, vaddr_end - 1);
 771
 772	return paddr_last;
 773}
 774
 
 775
 776/*
 777 * Create page table mapping for the physical memory for specific physical
 778 * addresses. Note that it can only be used to populate non-present entries.
 779 * The virtual and physical addresses have to be aligned on PMD level
 780 * down. It returns the last physical address mapped.
 781 */
 782unsigned long __meminit
 783kernel_physical_mapping_init(unsigned long paddr_start,
 784			     unsigned long paddr_end,
 785			     unsigned long page_size_mask, pgprot_t prot)
 786{
 787	return __kernel_physical_mapping_init(paddr_start, paddr_end,
 788					      page_size_mask, prot, true);
 789}
 790
 791/*
 792 * This function is similar to kernel_physical_mapping_init() above with the
 793 * exception that it uses set_{pud,pmd}() instead of the set_{pud,pte}_safe()
 794 * when updating the mapping. The caller is responsible to flush the TLBs after
 795 * the function returns.
 796 */
 797unsigned long __meminit
 798kernel_physical_mapping_change(unsigned long paddr_start,
 799			       unsigned long paddr_end,
 800			       unsigned long page_size_mask)
 801{
 802	return __kernel_physical_mapping_init(paddr_start, paddr_end,
 803					      page_size_mask, PAGE_KERNEL,
 804					      false);
 805}
 806
 807#ifndef CONFIG_NUMA
 808void __init initmem_init(void)
 809{
 810	memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
 811}
 812#endif
 813
 814void __init paging_init(void)
 815{
 
 816	sparse_init();
 817
 818	/*
 819	 * clear the default setting with node 0
 820	 * note: don't use nodes_clear here, that is really clearing when
 821	 *	 numa support is not compiled in, and later node_set_state
 822	 *	 will not set it back.
 823	 */
 824	node_clear_state(0, N_MEMORY);
 825	node_clear_state(0, N_NORMAL_MEMORY);
 
 826
 827	zone_sizes_init();
 828}
 829
 830#ifdef CONFIG_SPARSEMEM_VMEMMAP
 831#define PAGE_UNUSED 0xFD
 832
 833/*
 834 * The unused vmemmap range, which was not yet memset(PAGE_UNUSED), ranges
 835 * from unused_pmd_start to next PMD_SIZE boundary.
 836 */
 837static unsigned long unused_pmd_start __meminitdata;
 838
 839static void __meminit vmemmap_flush_unused_pmd(void)
 840{
 841	if (!unused_pmd_start)
 842		return;
 843	/*
 844	 * Clears (unused_pmd_start, PMD_END]
 845	 */
 846	memset((void *)unused_pmd_start, PAGE_UNUSED,
 847	       ALIGN(unused_pmd_start, PMD_SIZE) - unused_pmd_start);
 848	unused_pmd_start = 0;
 849}
 850
 851#ifdef CONFIG_MEMORY_HOTPLUG
 852/* Returns true if the PMD is completely unused and thus it can be freed */
 853static bool __meminit vmemmap_pmd_is_unused(unsigned long addr, unsigned long end)
 854{
 855	unsigned long start = ALIGN_DOWN(addr, PMD_SIZE);
 856
 857	/*
 858	 * Flush the unused range cache to ensure that memchr_inv() will work
 859	 * for the whole range.
 860	 */
 861	vmemmap_flush_unused_pmd();
 862	memset((void *)addr, PAGE_UNUSED, end - addr);
 863
 864	return !memchr_inv((void *)start, PAGE_UNUSED, PMD_SIZE);
 865}
 866#endif
 867
 868static void __meminit __vmemmap_use_sub_pmd(unsigned long start)
 869{
 870	/*
 871	 * As we expect to add in the same granularity as we remove, it's
 872	 * sufficient to mark only some piece used to block the memmap page from
 873	 * getting removed when removing some other adjacent memmap (just in
 874	 * case the first memmap never gets initialized e.g., because the memory
 875	 * block never gets onlined).
 876	 */
 877	memset((void *)start, 0, sizeof(struct page));
 878}
 879
 880static void __meminit vmemmap_use_sub_pmd(unsigned long start, unsigned long end)
 881{
 882	/*
 883	 * We only optimize if the new used range directly follows the
 884	 * previously unused range (esp., when populating consecutive sections).
 885	 */
 886	if (unused_pmd_start == start) {
 887		if (likely(IS_ALIGNED(end, PMD_SIZE)))
 888			unused_pmd_start = 0;
 889		else
 890			unused_pmd_start = end;
 891		return;
 892	}
 893
 894	/*
 895	 * If the range does not contiguously follows previous one, make sure
 896	 * to mark the unused range of the previous one so it can be removed.
 897	 */
 898	vmemmap_flush_unused_pmd();
 899	__vmemmap_use_sub_pmd(start);
 900}
 901
 902
 903static void __meminit vmemmap_use_new_sub_pmd(unsigned long start, unsigned long end)
 904{
 905	const unsigned long page = ALIGN_DOWN(start, PMD_SIZE);
 906
 907	vmemmap_flush_unused_pmd();
 908
 909	/*
 910	 * Could be our memmap page is filled with PAGE_UNUSED already from a
 911	 * previous remove. Make sure to reset it.
 912	 */
 913	__vmemmap_use_sub_pmd(start);
 914
 915	/*
 916	 * Mark with PAGE_UNUSED the unused parts of the new memmap range
 917	 */
 918	if (!IS_ALIGNED(start, PMD_SIZE))
 919		memset((void *)page, PAGE_UNUSED, start - page);
 920
 921	/*
 922	 * We want to avoid memset(PAGE_UNUSED) when populating the vmemmap of
 923	 * consecutive sections. Remember for the last added PMD where the
 924	 * unused range begins.
 925	 */
 926	if (!IS_ALIGNED(end, PMD_SIZE))
 927		unused_pmd_start = end;
 928}
 929#endif
 930
 931/*
 932 * Memory hotplug specific functions
 933 */
 934#ifdef CONFIG_MEMORY_HOTPLUG
 935/*
 936 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
 937 * updating.
 938 */
 939static void update_end_of_memory_vars(u64 start, u64 size)
 940{
 941	unsigned long end_pfn = PFN_UP(start + size);
 942
 943	if (end_pfn > max_pfn) {
 944		max_pfn = end_pfn;
 945		max_low_pfn = end_pfn;
 946		high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
 947	}
 948}
 949
 950int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
 951	      struct mhp_params *params)
 
 
 
 952{
 
 
 
 
 953	int ret;
 954
 955	ret = __add_pages(nid, start_pfn, nr_pages, params);
 
 
 956	WARN_ON_ONCE(ret);
 957
 958	/* update max_pfn, max_low_pfn and high_memory */
 959	update_end_of_memory_vars(start_pfn << PAGE_SHIFT,
 960				  nr_pages << PAGE_SHIFT);
 961
 962	return ret;
 963}
 
 964
 965int arch_add_memory(int nid, u64 start, u64 size,
 966		    struct mhp_params *params)
 967{
 968	unsigned long start_pfn = start >> PAGE_SHIFT;
 969	unsigned long nr_pages = size >> PAGE_SHIFT;
 970
 971	init_memory_mapping(start, start + size, params->pgprot);
 972
 973	return add_pages(nid, start_pfn, nr_pages, params);
 974}
 975
 976static void __meminit free_pagetable(struct page *page, int order)
 977{
 978	unsigned long magic;
 979	unsigned int nr_pages = 1 << order;
 980
 981	/* bootmem page has reserved flag */
 982	if (PageReserved(page)) {
 983		__ClearPageReserved(page);
 984
 985		magic = page->index;
 986		if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
 987			while (nr_pages--)
 988				put_page_bootmem(page++);
 989		} else
 990			while (nr_pages--)
 991				free_reserved_page(page++);
 992	} else
 993		free_pages((unsigned long)page_address(page), order);
 994}
 995
 996static void __meminit free_hugepage_table(struct page *page,
 997		struct vmem_altmap *altmap)
 998{
 999	if (altmap)
1000		vmem_altmap_free(altmap, PMD_SIZE / PAGE_SIZE);
1001	else
1002		free_pagetable(page, get_order(PMD_SIZE));
1003}
1004
1005static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
1006{
1007	pte_t *pte;
1008	int i;
1009
1010	for (i = 0; i < PTRS_PER_PTE; i++) {
1011		pte = pte_start + i;
1012		if (!pte_none(*pte))
1013			return;
1014	}
1015
1016	/* free a pte table */
1017	free_pagetable(pmd_page(*pmd), 0);
1018	spin_lock(&init_mm.page_table_lock);
1019	pmd_clear(pmd);
1020	spin_unlock(&init_mm.page_table_lock);
1021}
1022
1023static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
1024{
1025	pmd_t *pmd;
1026	int i;
1027
1028	for (i = 0; i < PTRS_PER_PMD; i++) {
1029		pmd = pmd_start + i;
1030		if (!pmd_none(*pmd))
1031			return;
1032	}
1033
1034	/* free a pmd table */
1035	free_pagetable(pud_page(*pud), 0);
1036	spin_lock(&init_mm.page_table_lock);
1037	pud_clear(pud);
1038	spin_unlock(&init_mm.page_table_lock);
1039}
1040
1041static void __meminit free_pud_table(pud_t *pud_start, p4d_t *p4d)
 
1042{
1043	pud_t *pud;
1044	int i;
1045
1046	for (i = 0; i < PTRS_PER_PUD; i++) {
1047		pud = pud_start + i;
1048		if (!pud_none(*pud))
1049			return;
1050	}
1051
1052	/* free a pud table */
1053	free_pagetable(p4d_page(*p4d), 0);
1054	spin_lock(&init_mm.page_table_lock);
1055	p4d_clear(p4d);
1056	spin_unlock(&init_mm.page_table_lock);
 
 
1057}
1058
1059static void __meminit
1060remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
1061		 bool direct)
1062{
1063	unsigned long next, pages = 0;
1064	pte_t *pte;
 
1065	phys_addr_t phys_addr;
1066
1067	pte = pte_start + pte_index(addr);
1068	for (; addr < end; addr = next, pte++) {
1069		next = (addr + PAGE_SIZE) & PAGE_MASK;
1070		if (next > end)
1071			next = end;
1072
1073		if (!pte_present(*pte))
1074			continue;
1075
1076		/*
1077		 * We mapped [0,1G) memory as identity mapping when
1078		 * initializing, in arch/x86/kernel/head_64.S. These
1079		 * pagetables cannot be removed.
1080		 */
1081		phys_addr = pte_val(*pte) + (addr & PAGE_MASK);
1082		if (phys_addr < (phys_addr_t)0x40000000)
1083			return;
1084
1085		if (!direct)
1086			free_pagetable(pte_page(*pte), 0);
 
 
 
 
 
 
1087
1088		spin_lock(&init_mm.page_table_lock);
1089		pte_clear(&init_mm, addr, pte);
1090		spin_unlock(&init_mm.page_table_lock);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1091
1092		/* For non-direct mapping, pages means nothing. */
1093		pages++;
 
 
 
1094	}
1095
1096	/* Call free_pte_table() in remove_pmd_table(). */
1097	flush_tlb_all();
1098	if (direct)
1099		update_page_count(PG_LEVEL_4K, -pages);
1100}
1101
1102static void __meminit
1103remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
1104		 bool direct, struct vmem_altmap *altmap)
1105{
1106	unsigned long next, pages = 0;
1107	pte_t *pte_base;
1108	pmd_t *pmd;
 
1109
1110	pmd = pmd_start + pmd_index(addr);
1111	for (; addr < end; addr = next, pmd++) {
1112		next = pmd_addr_end(addr, end);
1113
1114		if (!pmd_present(*pmd))
1115			continue;
1116
1117		if (pmd_large(*pmd)) {
1118			if (IS_ALIGNED(addr, PMD_SIZE) &&
1119			    IS_ALIGNED(next, PMD_SIZE)) {
1120				if (!direct)
1121					free_hugepage_table(pmd_page(*pmd),
1122							    altmap);
1123
1124				spin_lock(&init_mm.page_table_lock);
1125				pmd_clear(pmd);
1126				spin_unlock(&init_mm.page_table_lock);
1127				pages++;
1128			}
1129#ifdef CONFIG_SPARSEMEM_VMEMMAP
1130			else if (vmemmap_pmd_is_unused(addr, next)) {
1131					free_hugepage_table(pmd_page(*pmd),
1132							    altmap);
 
 
 
 
 
1133					spin_lock(&init_mm.page_table_lock);
1134					pmd_clear(pmd);
1135					spin_unlock(&init_mm.page_table_lock);
 
1136			}
1137#endif
1138			continue;
1139		}
1140
1141		pte_base = (pte_t *)pmd_page_vaddr(*pmd);
1142		remove_pte_table(pte_base, addr, next, direct);
1143		free_pte_table(pte_base, pmd);
1144	}
1145
1146	/* Call free_pmd_table() in remove_pud_table(). */
1147	if (direct)
1148		update_page_count(PG_LEVEL_2M, -pages);
1149}
1150
1151static void __meminit
1152remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
1153		 struct vmem_altmap *altmap, bool direct)
1154{
1155	unsigned long next, pages = 0;
1156	pmd_t *pmd_base;
1157	pud_t *pud;
 
1158
1159	pud = pud_start + pud_index(addr);
1160	for (; addr < end; addr = next, pud++) {
1161		next = pud_addr_end(addr, end);
1162
1163		if (!pud_present(*pud))
1164			continue;
1165
1166		if (pud_large(*pud) &&
1167		    IS_ALIGNED(addr, PUD_SIZE) &&
1168		    IS_ALIGNED(next, PUD_SIZE)) {
1169			spin_lock(&init_mm.page_table_lock);
1170			pud_clear(pud);
1171			spin_unlock(&init_mm.page_table_lock);
1172			pages++;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1173			continue;
1174		}
1175
1176		pmd_base = pmd_offset(pud, 0);
1177		remove_pmd_table(pmd_base, addr, next, direct, altmap);
1178		free_pmd_table(pmd_base, pud);
1179	}
1180
1181	if (direct)
1182		update_page_count(PG_LEVEL_1G, -pages);
1183}
1184
1185static void __meminit
1186remove_p4d_table(p4d_t *p4d_start, unsigned long addr, unsigned long end,
1187		 struct vmem_altmap *altmap, bool direct)
1188{
1189	unsigned long next, pages = 0;
1190	pud_t *pud_base;
1191	p4d_t *p4d;
1192
1193	p4d = p4d_start + p4d_index(addr);
1194	for (; addr < end; addr = next, p4d++) {
1195		next = p4d_addr_end(addr, end);
1196
1197		if (!p4d_present(*p4d))
1198			continue;
1199
1200		BUILD_BUG_ON(p4d_large(*p4d));
1201
1202		pud_base = pud_offset(p4d, 0);
1203		remove_pud_table(pud_base, addr, next, altmap, direct);
1204		/*
1205		 * For 4-level page tables we do not want to free PUDs, but in the
1206		 * 5-level case we should free them. This code will have to change
1207		 * to adapt for boot-time switching between 4 and 5 level page tables.
1208		 */
1209		if (pgtable_l5_enabled())
1210			free_pud_table(pud_base, p4d);
1211	}
1212
1213	if (direct)
1214		update_page_count(PG_LEVEL_512G, -pages);
1215}
1216
1217/* start and end are both virtual address. */
1218static void __meminit
1219remove_pagetable(unsigned long start, unsigned long end, bool direct,
1220		struct vmem_altmap *altmap)
1221{
1222	unsigned long next;
1223	unsigned long addr;
1224	pgd_t *pgd;
1225	p4d_t *p4d;
 
1226
1227	for (addr = start; addr < end; addr = next) {
1228		next = pgd_addr_end(addr, end);
1229
1230		pgd = pgd_offset_k(addr);
1231		if (!pgd_present(*pgd))
1232			continue;
1233
1234		p4d = p4d_offset(pgd, 0);
1235		remove_p4d_table(p4d, addr, next, altmap, direct);
 
 
1236	}
1237
 
 
 
1238	flush_tlb_all();
1239}
1240
1241void __ref vmemmap_free(unsigned long start, unsigned long end,
1242		struct vmem_altmap *altmap)
1243{
1244	VM_BUG_ON(!PAGE_ALIGNED(start));
1245	VM_BUG_ON(!PAGE_ALIGNED(end));
1246
1247	remove_pagetable(start, end, false, altmap);
1248}
1249
 
1250static void __meminit
1251kernel_physical_mapping_remove(unsigned long start, unsigned long end)
1252{
1253	start = (unsigned long)__va(start);
1254	end = (unsigned long)__va(end);
1255
1256	remove_pagetable(start, end, true, NULL);
1257}
1258
1259void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
1260{
1261	unsigned long start_pfn = start >> PAGE_SHIFT;
1262	unsigned long nr_pages = size >> PAGE_SHIFT;
 
 
1263
1264	__remove_pages(start_pfn, nr_pages, altmap);
1265	kernel_physical_mapping_remove(start, start + size);
 
 
 
 
1266}
 
1267#endif /* CONFIG_MEMORY_HOTPLUG */
1268
1269static struct kcore_list kcore_vsyscall;
1270
1271static void __init register_page_bootmem_info(void)
1272{
1273#if defined(CONFIG_NUMA) || defined(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP)
1274	int i;
1275
1276	for_each_online_node(i)
1277		register_page_bootmem_info_node(NODE_DATA(i));
1278#endif
1279}
1280
1281/*
1282 * Pre-allocates page-table pages for the vmalloc area in the kernel page-table.
1283 * Only the level which needs to be synchronized between all page-tables is
1284 * allocated because the synchronization can be expensive.
1285 */
1286static void __init preallocate_vmalloc_pages(void)
1287{
1288	unsigned long addr;
1289	const char *lvl;
1290
1291	for (addr = VMALLOC_START; addr <= VMEMORY_END; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
1292		pgd_t *pgd = pgd_offset_k(addr);
1293		p4d_t *p4d;
1294		pud_t *pud;
1295
1296		lvl = "p4d";
1297		p4d = p4d_alloc(&init_mm, pgd, addr);
1298		if (!p4d)
1299			goto failed;
1300
1301		if (pgtable_l5_enabled())
1302			continue;
 
1303
1304		/*
1305		 * The goal here is to allocate all possibly required
1306		 * hardware page tables pointed to by the top hardware
1307		 * level.
1308		 *
1309		 * On 4-level systems, the P4D layer is folded away and
1310		 * the above code does no preallocation.  Below, go down
1311		 * to the pud _software_ level to ensure the second
1312		 * hardware level is allocated on 4-level systems too.
1313		 */
1314		lvl = "pud";
1315		pud = pud_alloc(&init_mm, p4d, addr);
1316		if (!pud)
1317			goto failed;
1318	}
1319
1320	return;
 
1321
1322failed:
 
 
1323
1324	/*
1325	 * The pages have to be there now or they will be missing in
1326	 * process page-tables later.
1327	 */
1328	panic("Failed to pre-allocate %s pages for vmalloc area\n", lvl);
1329}
1330
1331void __init mem_init(void)
1332{
1333	pci_iommu_alloc();
 
1334
1335	/* clear_bss() already clear the empty_zero_page */
 
1336
1337	/* this will put all memory onto the freelists */
1338	memblock_free_all();
1339	after_bootmem = 1;
1340	x86_init.hyper.init_after_bootmem();
1341
1342	/*
1343	 * Must be done after boot memory is put on freelist, because here we
1344	 * might set fields in deferred struct pages that have not yet been
1345	 * initialized, and memblock_free_all() initializes all the reserved
1346	 * deferred pages for us.
1347	 */
1348	register_page_bootmem_info();
 
 
 
 
 
 
1349
1350	/* Register memory areas for /proc/kcore */
1351	if (get_gate_vma(&init_mm))
1352		kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR, PAGE_SIZE, KCORE_USER);
1353
1354	preallocate_vmalloc_pages();
1355}
1356
1357#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1358int __init deferred_page_init_max_threads(const struct cpumask *node_cpumask)
1359{
1360	/*
1361	 * More CPUs always led to greater speedups on tested systems, up to
1362	 * all the nodes' CPUs.  Use all since the system is otherwise idle
1363	 * now.
1364	 */
1365	return max_t(int, cpumask_weight(node_cpumask), 1);
1366}
1367#endif
1368
1369int kernel_set_to_readonly;
1370
1371void mark_rodata_ro(void)
1372{
1373	unsigned long start = PFN_ALIGN(_text);
1374	unsigned long rodata_start = PFN_ALIGN(__start_rodata);
1375	unsigned long end = (unsigned long)__end_rodata_hpage_align;
1376	unsigned long text_end = PFN_ALIGN(_etext);
1377	unsigned long rodata_end = PFN_ALIGN(__end_rodata);
1378	unsigned long all_end;
1379
1380	printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
1381	       (end - start) >> 10);
1382	set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1383
1384	kernel_set_to_readonly = 1;
1385
1386	/*
1387	 * The rodata/data/bss/brk section (but not the kernel text!)
1388	 * should also be not-executable.
1389	 *
1390	 * We align all_end to PMD_SIZE because the existing mapping
1391	 * is a full PMD. If we would align _brk_end to PAGE_SIZE we
1392	 * split the PMD and the reminder between _brk_end and the end
1393	 * of the PMD will remain mapped executable.
1394	 *
1395	 * Any PMD which was setup after the one which covers _brk_end
1396	 * has been zapped already via cleanup_highmem().
1397	 */
1398	all_end = roundup((unsigned long)_brk_end, PMD_SIZE);
1399	set_memory_nx(text_end, (all_end - text_end) >> PAGE_SHIFT);
1400
1401	set_ftrace_ops_ro();
1402
1403#ifdef CONFIG_CPA_DEBUG
1404	printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
1405	set_memory_rw(start, (end-start) >> PAGE_SHIFT);
1406
1407	printk(KERN_INFO "Testing CPA: again\n");
1408	set_memory_ro(start, (end-start) >> PAGE_SHIFT);
1409#endif
1410
1411	free_kernel_image_pages("unused kernel image (text/rodata gap)",
1412				(void *)text_end, (void *)rodata_start);
1413	free_kernel_image_pages("unused kernel image (rodata/data gap)",
1414				(void *)rodata_end, (void *)_sdata);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1415
1416	debug_checkwx();
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1417}
1418
1419/*
1420 * Block size is the minimum amount of memory which can be hotplugged or
1421 * hotremoved. It must be power of two and must be equal or larger than
1422 * MIN_MEMORY_BLOCK_SIZE.
1423 */
1424#define MAX_BLOCK_SIZE (2UL << 30)
1425
1426/* Amount of ram needed to start using large blocks */
1427#define MEM_SIZE_FOR_LARGE_BLOCK (64UL << 30)
 
 
 
 
 
 
 
 
 
 
 
1428
1429/* Adjustable memory block size */
1430static unsigned long set_memory_block_size;
1431int __init set_memory_block_size_order(unsigned int order)
1432{
1433	unsigned long size = 1UL << order;
1434
1435	if (size > MEM_SIZE_FOR_LARGE_BLOCK || size < MIN_MEMORY_BLOCK_SIZE)
1436		return -EINVAL;
1437
1438	set_memory_block_size = size;
1439	return 0;
1440}
1441
1442static unsigned long probe_memory_block_size(void)
 
 
 
 
 
1443{
1444	unsigned long boot_mem_end = max_pfn << PAGE_SHIFT;
1445	unsigned long bz;
1446
1447	/* If memory block size has been set, then use it */
1448	bz = set_memory_block_size;
1449	if (bz)
1450		goto done;
1451
1452	/* Use regular block if RAM is smaller than MEM_SIZE_FOR_LARGE_BLOCK */
1453	if (boot_mem_end < MEM_SIZE_FOR_LARGE_BLOCK) {
1454		bz = MIN_MEMORY_BLOCK_SIZE;
1455		goto done;
1456	}
1457
1458	/*
1459	 * Use max block size to minimize overhead on bare metal, where
1460	 * alignment for memory hotplug isn't a concern.
1461	 */
1462	if (!boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
1463		bz = MAX_BLOCK_SIZE;
1464		goto done;
1465	}
1466
1467	/* Find the largest allowed block size that aligns to memory end */
1468	for (bz = MAX_BLOCK_SIZE; bz > MIN_MEMORY_BLOCK_SIZE; bz >>= 1) {
1469		if (IS_ALIGNED(boot_mem_end, bz))
1470			break;
1471	}
1472done:
1473	pr_info("x86/mm: Memory block size: %ldMB\n", bz >> 20);
1474
1475	return bz;
1476}
1477
1478static unsigned long memory_block_size_probed;
1479unsigned long memory_block_size_bytes(void)
1480{
1481	if (!memory_block_size_probed)
1482		memory_block_size_probed = probe_memory_block_size();
1483
1484	return memory_block_size_probed;
 
1485}
 
1486
1487#ifdef CONFIG_SPARSEMEM_VMEMMAP
1488/*
1489 * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1490 */
1491static long __meminitdata addr_start, addr_end;
1492static void __meminitdata *p_start, *p_end;
1493static int __meminitdata node_start;
1494
1495void __meminit vmemmap_set_pmd(pmd_t *pmd, void *p, int node,
1496			       unsigned long addr, unsigned long next)
1497{
1498	pte_t entry;
 
 
 
 
1499
1500	entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1501			PAGE_KERNEL_LARGE);
1502	set_pmd(pmd, __pmd(pte_val(entry)));
1503
1504	/* check to see if we have contiguous blocks */
1505	if (p_end != p || node_start != node) {
1506		if (p_start)
1507			pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1508				addr_start, addr_end-1, p_start, p_end-1, node_start);
1509		addr_start = addr;
1510		node_start = node;
1511		p_start = p;
1512	}
1513
1514	addr_end = addr + PMD_SIZE;
1515	p_end = p + PMD_SIZE;
 
1516
1517	if (!IS_ALIGNED(addr, PMD_SIZE) ||
1518		!IS_ALIGNED(next, PMD_SIZE))
1519		vmemmap_use_new_sub_pmd(addr, next);
1520}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1521
1522int __meminit vmemmap_check_pmd(pmd_t *pmd, int node,
1523				unsigned long addr, unsigned long next)
1524{
1525	int large = pmd_large(*pmd);
1526
1527	if (pmd_large(*pmd)) {
1528		vmemmap_verify((pte_t *)pmd, node, addr, next);
1529		vmemmap_use_sub_pmd(addr, next);
 
 
 
1530	}
1531
1532	return large;
1533}
1534
1535int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
1536		struct vmem_altmap *altmap)
1537{
1538	int err;
1539
1540	VM_BUG_ON(!PAGE_ALIGNED(start));
1541	VM_BUG_ON(!PAGE_ALIGNED(end));
1542
1543	if (end - start < PAGES_PER_SECTION * sizeof(struct page))
1544		err = vmemmap_populate_basepages(start, end, node, NULL);
1545	else if (boot_cpu_has(X86_FEATURE_PSE))
1546		err = vmemmap_populate_hugepages(start, end, node, altmap);
1547	else if (altmap) {
1548		pr_err_once("%s: no cpu support for altmap allocations\n",
1549				__func__);
1550		err = -ENOMEM;
1551	} else
1552		err = vmemmap_populate_basepages(start, end, node, NULL);
1553	if (!err)
1554		sync_global_pgds(start, end - 1);
1555	return err;
1556}
1557
1558#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
1559void register_page_bootmem_memmap(unsigned long section_nr,
1560				  struct page *start_page, unsigned long nr_pages)
1561{
1562	unsigned long addr = (unsigned long)start_page;
1563	unsigned long end = (unsigned long)(start_page + nr_pages);
1564	unsigned long next;
1565	pgd_t *pgd;
1566	p4d_t *p4d;
1567	pud_t *pud;
1568	pmd_t *pmd;
1569	unsigned int nr_pmd_pages;
1570	struct page *page;
1571
1572	for (; addr < end; addr = next) {
1573		pte_t *pte = NULL;
1574
1575		pgd = pgd_offset_k(addr);
1576		if (pgd_none(*pgd)) {
1577			next = (addr + PAGE_SIZE) & PAGE_MASK;
1578			continue;
1579		}
1580		get_page_bootmem(section_nr, pgd_page(*pgd), MIX_SECTION_INFO);
1581
1582		p4d = p4d_offset(pgd, addr);
1583		if (p4d_none(*p4d)) {
1584			next = (addr + PAGE_SIZE) & PAGE_MASK;
1585			continue;
1586		}
1587		get_page_bootmem(section_nr, p4d_page(*p4d), MIX_SECTION_INFO);
1588
1589		pud = pud_offset(p4d, addr);
1590		if (pud_none(*pud)) {
1591			next = (addr + PAGE_SIZE) & PAGE_MASK;
1592			continue;
1593		}
1594		get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO);
1595
1596		if (!boot_cpu_has(X86_FEATURE_PSE)) {
1597			next = (addr + PAGE_SIZE) & PAGE_MASK;
1598			pmd = pmd_offset(pud, addr);
1599			if (pmd_none(*pmd))
1600				continue;
1601			get_page_bootmem(section_nr, pmd_page(*pmd),
1602					 MIX_SECTION_INFO);
1603
1604			pte = pte_offset_kernel(pmd, addr);
1605			if (pte_none(*pte))
1606				continue;
1607			get_page_bootmem(section_nr, pte_page(*pte),
1608					 SECTION_INFO);
1609		} else {
1610			next = pmd_addr_end(addr, end);
1611
1612			pmd = pmd_offset(pud, addr);
1613			if (pmd_none(*pmd))
1614				continue;
1615
1616			nr_pmd_pages = 1 << get_order(PMD_SIZE);
1617			page = pmd_page(*pmd);
1618			while (nr_pmd_pages--)
1619				get_page_bootmem(section_nr, page++,
1620						 SECTION_INFO);
1621		}
1622	}
1623}
1624#endif
1625
1626void __meminit vmemmap_populate_print_last(void)
1627{
1628	if (p_start) {
1629		pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1630			addr_start, addr_end-1, p_start, p_end-1, node_start);
1631		p_start = NULL;
1632		p_end = NULL;
1633		node_start = 0;
1634	}
1635}
1636#endif