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   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			    !e820__mapped_any(paddr & PAGE_MASK, paddr_next,
 474					     E820_TYPE_ACPI))
 475				set_pte_init(pte, __pte(0), init);
 476			continue;
 477		}
 478
 479		/*
 480		 * We will re-use the existing mapping.
 481		 * Xen for example has some special requirements, like mapping
 482		 * pagetable pages as RO. So assume someone who pre-setup
 483		 * these mappings are more intelligent.
 484		 */
 485		if (!pte_none(*pte)) {
 486			if (!after_bootmem)
 487				pages++;
 488			continue;
 489		}
 490
 491		if (0)
 492			pr_info("   pte=%p addr=%lx pte=%016lx\n", pte, paddr,
 493				pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL).pte);
 494		pages++;
 495		set_pte_init(pte, pfn_pte(paddr >> PAGE_SHIFT, prot), init);
 496		paddr_last = (paddr & PAGE_MASK) + PAGE_SIZE;
 497	}
 498
 499	update_page_count(PG_LEVEL_4K, pages);
 500
 501	return paddr_last;
 502}
 503
 504/*
 505 * Create PMD level page table mapping for physical addresses. The virtual
 506 * and physical address have to be aligned at this level.
 507 * It returns the last physical address mapped.
 508 */
 509static unsigned long __meminit
 510phys_pmd_init(pmd_t *pmd_page, unsigned long paddr, unsigned long paddr_end,
 511	      unsigned long page_size_mask, pgprot_t prot, bool init)
 512{
 513	unsigned long pages = 0, paddr_next;
 514	unsigned long paddr_last = paddr_end;
 515
 516	int i = pmd_index(paddr);
 517
 518	for (; i < PTRS_PER_PMD; i++, paddr = paddr_next) {
 519		pmd_t *pmd = pmd_page + pmd_index(paddr);
 520		pte_t *pte;
 521		pgprot_t new_prot = prot;
 522
 523		paddr_next = (paddr & PMD_MASK) + PMD_SIZE;
 524		if (paddr >= paddr_end) {
 525			if (!after_bootmem &&
 526			    !e820__mapped_any(paddr & PMD_MASK, paddr_next,
 527					     E820_TYPE_RAM) &&
 528			    !e820__mapped_any(paddr & PMD_MASK, paddr_next,
 529					     E820_TYPE_RESERVED_KERN) &&
 530			    !e820__mapped_any(paddr & PMD_MASK, paddr_next,
 531					     E820_TYPE_ACPI))
 532				set_pmd_init(pmd, __pmd(0), init);
 533			continue;
 534		}
 535
 536		if (!pmd_none(*pmd)) {
 537			if (!pmd_leaf(*pmd)) {
 538				spin_lock(&init_mm.page_table_lock);
 539				pte = (pte_t *)pmd_page_vaddr(*pmd);
 540				paddr_last = phys_pte_init(pte, paddr,
 541							   paddr_end, prot,
 542							   init);
 543				spin_unlock(&init_mm.page_table_lock);
 544				continue;
 545			}
 546			/*
 547			 * If we are ok with PG_LEVEL_2M mapping, then we will
 548			 * use the existing mapping,
 549			 *
 550			 * Otherwise, we will split the large page mapping but
 551			 * use the same existing protection bits except for
 552			 * large page, so that we don't violate Intel's TLB
 553			 * Application note (317080) which says, while changing
 554			 * the page sizes, new and old translations should
 555			 * not differ with respect to page frame and
 556			 * attributes.
 557			 */
 558			if (page_size_mask & (1 << PG_LEVEL_2M)) {
 559				if (!after_bootmem)
 560					pages++;
 561				paddr_last = paddr_next;
 562				continue;
 563			}
 564			new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
 565		}
 566
 567		if (page_size_mask & (1<<PG_LEVEL_2M)) {
 568			pages++;
 569			spin_lock(&init_mm.page_table_lock);
 570			set_pmd_init(pmd,
 571				     pfn_pmd(paddr >> PAGE_SHIFT, prot_sethuge(prot)),
 572				     init);
 573			spin_unlock(&init_mm.page_table_lock);
 574			paddr_last = paddr_next;
 575			continue;
 576		}
 577
 578		pte = alloc_low_page();
 579		paddr_last = phys_pte_init(pte, paddr, paddr_end, new_prot, init);
 580
 581		spin_lock(&init_mm.page_table_lock);
 582		pmd_populate_kernel_init(&init_mm, pmd, pte, init);
 583		spin_unlock(&init_mm.page_table_lock);
 584	}
 585	update_page_count(PG_LEVEL_2M, pages);
 586	return paddr_last;
 587}
 588
 589/*
 590 * Create PUD level page table mapping for physical addresses. The virtual
 591 * and physical address do not have to be aligned at this level. KASLR can
 592 * randomize virtual addresses up to this level.
 593 * It returns the last physical address mapped.
 594 */
 595static unsigned long __meminit
 596phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end,
 597	      unsigned long page_size_mask, pgprot_t _prot, bool init)
 598{
 599	unsigned long pages = 0, paddr_next;
 600	unsigned long paddr_last = paddr_end;
 601	unsigned long vaddr = (unsigned long)__va(paddr);
 602	int i = pud_index(vaddr);
 603
 604	for (; i < PTRS_PER_PUD; i++, paddr = paddr_next) {
 605		pud_t *pud;
 606		pmd_t *pmd;
 607		pgprot_t prot = _prot;
 608
 609		vaddr = (unsigned long)__va(paddr);
 610		pud = pud_page + pud_index(vaddr);
 611		paddr_next = (paddr & PUD_MASK) + PUD_SIZE;
 612
 613		if (paddr >= paddr_end) {
 614			if (!after_bootmem &&
 615			    !e820__mapped_any(paddr & PUD_MASK, paddr_next,
 616					     E820_TYPE_RAM) &&
 617			    !e820__mapped_any(paddr & PUD_MASK, paddr_next,
 618					     E820_TYPE_RESERVED_KERN) &&
 619			    !e820__mapped_any(paddr & PUD_MASK, paddr_next,
 620					     E820_TYPE_ACPI))
 621				set_pud_init(pud, __pud(0), init);
 622			continue;
 623		}
 624
 625		if (!pud_none(*pud)) {
 626			if (!pud_leaf(*pud)) {
 627				pmd = pmd_offset(pud, 0);
 628				paddr_last = phys_pmd_init(pmd, paddr,
 629							   paddr_end,
 630							   page_size_mask,
 631							   prot, init);
 632				continue;
 633			}
 634			/*
 635			 * If we are ok with PG_LEVEL_1G mapping, then we will
 636			 * use the existing mapping.
 637			 *
 638			 * Otherwise, we will split the gbpage mapping but use
 639			 * the same existing protection  bits except for large
 640			 * page, so that we don't violate Intel's TLB
 641			 * Application note (317080) which says, while changing
 642			 * the page sizes, new and old translations should
 643			 * not differ with respect to page frame and
 644			 * attributes.
 645			 */
 646			if (page_size_mask & (1 << PG_LEVEL_1G)) {
 647				if (!after_bootmem)
 648					pages++;
 649				paddr_last = paddr_next;
 650				continue;
 651			}
 652			prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
 653		}
 654
 655		if (page_size_mask & (1<<PG_LEVEL_1G)) {
 656			pages++;
 657			spin_lock(&init_mm.page_table_lock);
 658			set_pud_init(pud,
 659				     pfn_pud(paddr >> PAGE_SHIFT, prot_sethuge(prot)),
 660				     init);
 661			spin_unlock(&init_mm.page_table_lock);
 662			paddr_last = paddr_next;
 663			continue;
 664		}
 665
 666		pmd = alloc_low_page();
 667		paddr_last = phys_pmd_init(pmd, paddr, paddr_end,
 668					   page_size_mask, prot, init);
 669
 670		spin_lock(&init_mm.page_table_lock);
 671		pud_populate_init(&init_mm, pud, pmd, init);
 672		spin_unlock(&init_mm.page_table_lock);
 673	}
 674
 675	update_page_count(PG_LEVEL_1G, pages);
 676
 677	return paddr_last;
 678}
 679
 680static unsigned long __meminit
 681phys_p4d_init(p4d_t *p4d_page, unsigned long paddr, unsigned long paddr_end,
 682	      unsigned long page_size_mask, pgprot_t prot, bool init)
 683{
 684	unsigned long vaddr, vaddr_end, vaddr_next, paddr_next, paddr_last;
 685
 686	paddr_last = paddr_end;
 687	vaddr = (unsigned long)__va(paddr);
 688	vaddr_end = (unsigned long)__va(paddr_end);
 689
 690	if (!pgtable_l5_enabled())
 691		return phys_pud_init((pud_t *) p4d_page, paddr, paddr_end,
 692				     page_size_mask, prot, init);
 693
 694	for (; vaddr < vaddr_end; vaddr = vaddr_next) {
 695		p4d_t *p4d = p4d_page + p4d_index(vaddr);
 696		pud_t *pud;
 697
 698		vaddr_next = (vaddr & P4D_MASK) + P4D_SIZE;
 699		paddr = __pa(vaddr);
 700
 701		if (paddr >= paddr_end) {
 702			paddr_next = __pa(vaddr_next);
 703			if (!after_bootmem &&
 704			    !e820__mapped_any(paddr & P4D_MASK, paddr_next,
 705					     E820_TYPE_RAM) &&
 706			    !e820__mapped_any(paddr & P4D_MASK, paddr_next,
 707					     E820_TYPE_RESERVED_KERN) &&
 708			    !e820__mapped_any(paddr & P4D_MASK, paddr_next,
 709					     E820_TYPE_ACPI))
 710				set_p4d_init(p4d, __p4d(0), init);
 711			continue;
 712		}
 713
 714		if (!p4d_none(*p4d)) {
 715			pud = pud_offset(p4d, 0);
 716			paddr_last = phys_pud_init(pud, paddr, __pa(vaddr_end),
 717					page_size_mask, prot, init);
 718			continue;
 719		}
 720
 721		pud = alloc_low_page();
 722		paddr_last = phys_pud_init(pud, paddr, __pa(vaddr_end),
 723					   page_size_mask, prot, init);
 724
 725		spin_lock(&init_mm.page_table_lock);
 726		p4d_populate_init(&init_mm, p4d, pud, init);
 727		spin_unlock(&init_mm.page_table_lock);
 728	}
 729
 730	return paddr_last;
 731}
 732
 733static unsigned long __meminit
 734__kernel_physical_mapping_init(unsigned long paddr_start,
 735			       unsigned long paddr_end,
 736			       unsigned long page_size_mask,
 737			       pgprot_t prot, bool init)
 738{
 739	bool pgd_changed = false;
 740	unsigned long vaddr, vaddr_start, vaddr_end, vaddr_next, paddr_last;
 741
 742	paddr_last = paddr_end;
 743	vaddr = (unsigned long)__va(paddr_start);
 744	vaddr_end = (unsigned long)__va(paddr_end);
 745	vaddr_start = vaddr;
 746
 747	for (; vaddr < vaddr_end; vaddr = vaddr_next) {
 748		pgd_t *pgd = pgd_offset_k(vaddr);
 749		p4d_t *p4d;
 750
 751		vaddr_next = (vaddr & PGDIR_MASK) + PGDIR_SIZE;
 752
 753		if (pgd_val(*pgd)) {
 754			p4d = (p4d_t *)pgd_page_vaddr(*pgd);
 755			paddr_last = phys_p4d_init(p4d, __pa(vaddr),
 756						   __pa(vaddr_end),
 757						   page_size_mask,
 758						   prot, init);
 759			continue;
 760		}
 761
 762		p4d = alloc_low_page();
 763		paddr_last = phys_p4d_init(p4d, __pa(vaddr), __pa(vaddr_end),
 764					   page_size_mask, prot, init);
 765
 766		spin_lock(&init_mm.page_table_lock);
 767		if (pgtable_l5_enabled())
 768			pgd_populate_init(&init_mm, pgd, p4d, init);
 769		else
 770			p4d_populate_init(&init_mm, p4d_offset(pgd, vaddr),
 771					  (pud_t *) p4d, init);
 772
 773		spin_unlock(&init_mm.page_table_lock);
 774		pgd_changed = true;
 775	}
 776
 777	if (pgd_changed)
 778		sync_global_pgds(vaddr_start, vaddr_end - 1);
 779
 780	return paddr_last;
 781}
 782
 783
 784/*
 785 * Create page table mapping for the physical memory for specific physical
 786 * addresses. Note that it can only be used to populate non-present entries.
 787 * The virtual and physical addresses have to be aligned on PMD level
 788 * down. It returns the last physical address mapped.
 789 */
 790unsigned long __meminit
 791kernel_physical_mapping_init(unsigned long paddr_start,
 792			     unsigned long paddr_end,
 793			     unsigned long page_size_mask, pgprot_t prot)
 794{
 795	return __kernel_physical_mapping_init(paddr_start, paddr_end,
 796					      page_size_mask, prot, true);
 797}
 798
 799/*
 800 * This function is similar to kernel_physical_mapping_init() above with the
 801 * exception that it uses set_{pud,pmd}() instead of the set_{pud,pte}_safe()
 802 * when updating the mapping. The caller is responsible to flush the TLBs after
 803 * the function returns.
 804 */
 805unsigned long __meminit
 806kernel_physical_mapping_change(unsigned long paddr_start,
 807			       unsigned long paddr_end,
 808			       unsigned long page_size_mask)
 809{
 810	return __kernel_physical_mapping_init(paddr_start, paddr_end,
 811					      page_size_mask, PAGE_KERNEL,
 812					      false);
 813}
 814
 815#ifndef CONFIG_NUMA
 816void __init initmem_init(void)
 817{
 818	memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
 819}
 820#endif
 821
 822void __init paging_init(void)
 823{
 824	sparse_init();
 825
 826	/*
 827	 * clear the default setting with node 0
 828	 * note: don't use nodes_clear here, that is really clearing when
 829	 *	 numa support is not compiled in, and later node_set_state
 830	 *	 will not set it back.
 831	 */
 832	node_clear_state(0, N_MEMORY);
 833	node_clear_state(0, N_NORMAL_MEMORY);
 834
 835	zone_sizes_init();
 836}
 837
 838#ifdef CONFIG_SPARSEMEM_VMEMMAP
 839#define PAGE_UNUSED 0xFD
 840
 841/*
 842 * The unused vmemmap range, which was not yet memset(PAGE_UNUSED), ranges
 843 * from unused_pmd_start to next PMD_SIZE boundary.
 844 */
 845static unsigned long unused_pmd_start __meminitdata;
 846
 847static void __meminit vmemmap_flush_unused_pmd(void)
 848{
 849	if (!unused_pmd_start)
 850		return;
 851	/*
 852	 * Clears (unused_pmd_start, PMD_END]
 853	 */
 854	memset((void *)unused_pmd_start, PAGE_UNUSED,
 855	       ALIGN(unused_pmd_start, PMD_SIZE) - unused_pmd_start);
 856	unused_pmd_start = 0;
 857}
 858
 859#ifdef CONFIG_MEMORY_HOTPLUG
 860/* Returns true if the PMD is completely unused and thus it can be freed */
 861static bool __meminit vmemmap_pmd_is_unused(unsigned long addr, unsigned long end)
 862{
 863	unsigned long start = ALIGN_DOWN(addr, PMD_SIZE);
 864
 865	/*
 866	 * Flush the unused range cache to ensure that memchr_inv() will work
 867	 * for the whole range.
 868	 */
 869	vmemmap_flush_unused_pmd();
 870	memset((void *)addr, PAGE_UNUSED, end - addr);
 871
 872	return !memchr_inv((void *)start, PAGE_UNUSED, PMD_SIZE);
 873}
 874#endif
 875
 876static void __meminit __vmemmap_use_sub_pmd(unsigned long start)
 877{
 878	/*
 879	 * As we expect to add in the same granularity as we remove, it's
 880	 * sufficient to mark only some piece used to block the memmap page from
 881	 * getting removed when removing some other adjacent memmap (just in
 882	 * case the first memmap never gets initialized e.g., because the memory
 883	 * block never gets onlined).
 884	 */
 885	memset((void *)start, 0, sizeof(struct page));
 886}
 887
 888static void __meminit vmemmap_use_sub_pmd(unsigned long start, unsigned long end)
 889{
 890	/*
 891	 * We only optimize if the new used range directly follows the
 892	 * previously unused range (esp., when populating consecutive sections).
 893	 */
 894	if (unused_pmd_start == start) {
 895		if (likely(IS_ALIGNED(end, PMD_SIZE)))
 896			unused_pmd_start = 0;
 897		else
 898			unused_pmd_start = end;
 899		return;
 900	}
 901
 902	/*
 903	 * If the range does not contiguously follows previous one, make sure
 904	 * to mark the unused range of the previous one so it can be removed.
 905	 */
 906	vmemmap_flush_unused_pmd();
 907	__vmemmap_use_sub_pmd(start);
 908}
 909
 910
 911static void __meminit vmemmap_use_new_sub_pmd(unsigned long start, unsigned long end)
 912{
 913	const unsigned long page = ALIGN_DOWN(start, PMD_SIZE);
 914
 915	vmemmap_flush_unused_pmd();
 916
 917	/*
 918	 * Could be our memmap page is filled with PAGE_UNUSED already from a
 919	 * previous remove. Make sure to reset it.
 920	 */
 921	__vmemmap_use_sub_pmd(start);
 922
 923	/*
 924	 * Mark with PAGE_UNUSED the unused parts of the new memmap range
 925	 */
 926	if (!IS_ALIGNED(start, PMD_SIZE))
 927		memset((void *)page, PAGE_UNUSED, start - page);
 928
 929	/*
 930	 * We want to avoid memset(PAGE_UNUSED) when populating the vmemmap of
 931	 * consecutive sections. Remember for the last added PMD where the
 932	 * unused range begins.
 933	 */
 934	if (!IS_ALIGNED(end, PMD_SIZE))
 935		unused_pmd_start = end;
 936}
 937#endif
 938
 939/*
 940 * Memory hotplug specific functions
 941 */
 942#ifdef CONFIG_MEMORY_HOTPLUG
 943/*
 944 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
 945 * updating.
 946 */
 947static void update_end_of_memory_vars(u64 start, u64 size)
 948{
 949	unsigned long end_pfn = PFN_UP(start + size);
 950
 951	if (end_pfn > max_pfn) {
 952		max_pfn = end_pfn;
 953		max_low_pfn = end_pfn;
 954		high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
 955	}
 956}
 957
 958int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
 959	      struct mhp_params *params)
 960{
 961	unsigned long end = ((start_pfn + nr_pages) << PAGE_SHIFT) - 1;
 962	int ret;
 963
 964	if (WARN_ON_ONCE(end > DIRECT_MAP_PHYSMEM_END))
 965		return -ERANGE;
 966
 967	ret = __add_pages(nid, start_pfn, nr_pages, params);
 968	WARN_ON_ONCE(ret);
 969
 970	/* update max_pfn, max_low_pfn and high_memory */
 971	update_end_of_memory_vars(start_pfn << PAGE_SHIFT,
 972				  nr_pages << PAGE_SHIFT);
 973
 974	return ret;
 975}
 976
 977int arch_add_memory(int nid, u64 start, u64 size,
 978		    struct mhp_params *params)
 979{
 980	unsigned long start_pfn = start >> PAGE_SHIFT;
 981	unsigned long nr_pages = size >> PAGE_SHIFT;
 982
 983	init_memory_mapping(start, start + size, params->pgprot);
 984
 985	return add_pages(nid, start_pfn, nr_pages, params);
 986}
 987
 988static void free_reserved_pages(struct page *page, unsigned long nr_pages)
 989{
 990	while (nr_pages--)
 991		free_reserved_page(page++);
 992}
 993
 994static void __meminit free_pagetable(struct page *page, int order)
 995{
 996	/* bootmem page has reserved flag */
 997	if (PageReserved(page)) {
 998		unsigned long nr_pages = 1 << order;
 999#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
1000		enum bootmem_type type = bootmem_type(page);
1001
1002		if (type == SECTION_INFO || type == MIX_SECTION_INFO) {
1003			while (nr_pages--)
1004				put_page_bootmem(page++);
1005		} else {
1006			free_reserved_pages(page, nr_pages);
1007		}
1008#else
1009		free_reserved_pages(page, nr_pages);
1010#endif
1011	} else {
1012		free_pages((unsigned long)page_address(page), order);
1013	}
1014}
1015
1016static void __meminit free_hugepage_table(struct page *page,
1017		struct vmem_altmap *altmap)
1018{
1019	if (altmap)
1020		vmem_altmap_free(altmap, PMD_SIZE / PAGE_SIZE);
1021	else
1022		free_pagetable(page, get_order(PMD_SIZE));
1023}
1024
1025static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
1026{
1027	pte_t *pte;
1028	int i;
1029
1030	for (i = 0; i < PTRS_PER_PTE; i++) {
1031		pte = pte_start + i;
1032		if (!pte_none(*pte))
1033			return;
1034	}
1035
1036	/* free a pte table */
1037	free_pagetable(pmd_page(*pmd), 0);
1038	spin_lock(&init_mm.page_table_lock);
1039	pmd_clear(pmd);
1040	spin_unlock(&init_mm.page_table_lock);
1041}
1042
1043static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
1044{
1045	pmd_t *pmd;
1046	int i;
1047
1048	for (i = 0; i < PTRS_PER_PMD; i++) {
1049		pmd = pmd_start + i;
1050		if (!pmd_none(*pmd))
1051			return;
1052	}
1053
1054	/* free a pmd table */
1055	free_pagetable(pud_page(*pud), 0);
1056	spin_lock(&init_mm.page_table_lock);
1057	pud_clear(pud);
1058	spin_unlock(&init_mm.page_table_lock);
1059}
1060
1061static void __meminit free_pud_table(pud_t *pud_start, p4d_t *p4d)
1062{
1063	pud_t *pud;
1064	int i;
1065
1066	for (i = 0; i < PTRS_PER_PUD; i++) {
1067		pud = pud_start + i;
1068		if (!pud_none(*pud))
1069			return;
1070	}
1071
1072	/* free a pud table */
1073	free_pagetable(p4d_page(*p4d), 0);
1074	spin_lock(&init_mm.page_table_lock);
1075	p4d_clear(p4d);
1076	spin_unlock(&init_mm.page_table_lock);
1077}
1078
1079static void __meminit
1080remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
1081		 bool direct)
1082{
1083	unsigned long next, pages = 0;
1084	pte_t *pte;
1085	phys_addr_t phys_addr;
1086
1087	pte = pte_start + pte_index(addr);
1088	for (; addr < end; addr = next, pte++) {
1089		next = (addr + PAGE_SIZE) & PAGE_MASK;
1090		if (next > end)
1091			next = end;
1092
1093		if (!pte_present(*pte))
1094			continue;
1095
1096		/*
1097		 * We mapped [0,1G) memory as identity mapping when
1098		 * initializing, in arch/x86/kernel/head_64.S. These
1099		 * pagetables cannot be removed.
1100		 */
1101		phys_addr = pte_val(*pte) + (addr & PAGE_MASK);
1102		if (phys_addr < (phys_addr_t)0x40000000)
1103			return;
1104
1105		if (!direct)
1106			free_pagetable(pte_page(*pte), 0);
1107
1108		spin_lock(&init_mm.page_table_lock);
1109		pte_clear(&init_mm, addr, pte);
1110		spin_unlock(&init_mm.page_table_lock);
1111
1112		/* For non-direct mapping, pages means nothing. */
1113		pages++;
1114	}
1115
1116	/* Call free_pte_table() in remove_pmd_table(). */
1117	flush_tlb_all();
1118	if (direct)
1119		update_page_count(PG_LEVEL_4K, -pages);
1120}
1121
1122static void __meminit
1123remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
1124		 bool direct, struct vmem_altmap *altmap)
1125{
1126	unsigned long next, pages = 0;
1127	pte_t *pte_base;
1128	pmd_t *pmd;
1129
1130	pmd = pmd_start + pmd_index(addr);
1131	for (; addr < end; addr = next, pmd++) {
1132		next = pmd_addr_end(addr, end);
1133
1134		if (!pmd_present(*pmd))
1135			continue;
1136
1137		if (pmd_leaf(*pmd)) {
1138			if (IS_ALIGNED(addr, PMD_SIZE) &&
1139			    IS_ALIGNED(next, PMD_SIZE)) {
1140				if (!direct)
1141					free_hugepage_table(pmd_page(*pmd),
1142							    altmap);
1143
1144				spin_lock(&init_mm.page_table_lock);
1145				pmd_clear(pmd);
1146				spin_unlock(&init_mm.page_table_lock);
1147				pages++;
1148			}
1149#ifdef CONFIG_SPARSEMEM_VMEMMAP
1150			else if (vmemmap_pmd_is_unused(addr, next)) {
1151					free_hugepage_table(pmd_page(*pmd),
1152							    altmap);
1153					spin_lock(&init_mm.page_table_lock);
1154					pmd_clear(pmd);
1155					spin_unlock(&init_mm.page_table_lock);
1156			}
1157#endif
1158			continue;
1159		}
1160
1161		pte_base = (pte_t *)pmd_page_vaddr(*pmd);
1162		remove_pte_table(pte_base, addr, next, direct);
1163		free_pte_table(pte_base, pmd);
1164	}
1165
1166	/* Call free_pmd_table() in remove_pud_table(). */
1167	if (direct)
1168		update_page_count(PG_LEVEL_2M, -pages);
1169}
1170
1171static void __meminit
1172remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
1173		 struct vmem_altmap *altmap, bool direct)
1174{
1175	unsigned long next, pages = 0;
1176	pmd_t *pmd_base;
1177	pud_t *pud;
1178
1179	pud = pud_start + pud_index(addr);
1180	for (; addr < end; addr = next, pud++) {
1181		next = pud_addr_end(addr, end);
1182
1183		if (!pud_present(*pud))
1184			continue;
1185
1186		if (pud_leaf(*pud) &&
1187		    IS_ALIGNED(addr, PUD_SIZE) &&
1188		    IS_ALIGNED(next, PUD_SIZE)) {
1189			spin_lock(&init_mm.page_table_lock);
1190			pud_clear(pud);
1191			spin_unlock(&init_mm.page_table_lock);
1192			pages++;
1193			continue;
1194		}
1195
1196		pmd_base = pmd_offset(pud, 0);
1197		remove_pmd_table(pmd_base, addr, next, direct, altmap);
1198		free_pmd_table(pmd_base, pud);
1199	}
1200
1201	if (direct)
1202		update_page_count(PG_LEVEL_1G, -pages);
1203}
1204
1205static void __meminit
1206remove_p4d_table(p4d_t *p4d_start, unsigned long addr, unsigned long end,
1207		 struct vmem_altmap *altmap, bool direct)
1208{
1209	unsigned long next, pages = 0;
1210	pud_t *pud_base;
1211	p4d_t *p4d;
1212
1213	p4d = p4d_start + p4d_index(addr);
1214	for (; addr < end; addr = next, p4d++) {
1215		next = p4d_addr_end(addr, end);
1216
1217		if (!p4d_present(*p4d))
1218			continue;
1219
1220		BUILD_BUG_ON(p4d_leaf(*p4d));
1221
1222		pud_base = pud_offset(p4d, 0);
1223		remove_pud_table(pud_base, addr, next, altmap, direct);
1224		/*
1225		 * For 4-level page tables we do not want to free PUDs, but in the
1226		 * 5-level case we should free them. This code will have to change
1227		 * to adapt for boot-time switching between 4 and 5 level page tables.
1228		 */
1229		if (pgtable_l5_enabled())
1230			free_pud_table(pud_base, p4d);
1231	}
1232
1233	if (direct)
1234		update_page_count(PG_LEVEL_512G, -pages);
1235}
1236
1237/* start and end are both virtual address. */
1238static void __meminit
1239remove_pagetable(unsigned long start, unsigned long end, bool direct,
1240		struct vmem_altmap *altmap)
1241{
1242	unsigned long next;
1243	unsigned long addr;
1244	pgd_t *pgd;
1245	p4d_t *p4d;
1246
1247	for (addr = start; addr < end; addr = next) {
1248		next = pgd_addr_end(addr, end);
1249
1250		pgd = pgd_offset_k(addr);
1251		if (!pgd_present(*pgd))
1252			continue;
1253
1254		p4d = p4d_offset(pgd, 0);
1255		remove_p4d_table(p4d, addr, next, altmap, direct);
1256	}
1257
1258	flush_tlb_all();
1259}
1260
1261void __ref vmemmap_free(unsigned long start, unsigned long end,
1262		struct vmem_altmap *altmap)
1263{
1264	VM_BUG_ON(!PAGE_ALIGNED(start));
1265	VM_BUG_ON(!PAGE_ALIGNED(end));
1266
1267	remove_pagetable(start, end, false, altmap);
1268}
1269
1270static void __meminit
1271kernel_physical_mapping_remove(unsigned long start, unsigned long end)
1272{
1273	start = (unsigned long)__va(start);
1274	end = (unsigned long)__va(end);
1275
1276	remove_pagetable(start, end, true, NULL);
1277}
1278
1279void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
1280{
1281	unsigned long start_pfn = start >> PAGE_SHIFT;
1282	unsigned long nr_pages = size >> PAGE_SHIFT;
1283
1284	__remove_pages(start_pfn, nr_pages, altmap);
1285	kernel_physical_mapping_remove(start, start + size);
1286}
1287#endif /* CONFIG_MEMORY_HOTPLUG */
1288
1289static struct kcore_list kcore_vsyscall;
1290
1291static void __init register_page_bootmem_info(void)
1292{
1293#if defined(CONFIG_NUMA) || defined(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP)
1294	int i;
1295
1296	for_each_online_node(i)
1297		register_page_bootmem_info_node(NODE_DATA(i));
1298#endif
1299}
1300
1301/*
1302 * Pre-allocates page-table pages for the vmalloc area in the kernel page-table.
1303 * Only the level which needs to be synchronized between all page-tables is
1304 * allocated because the synchronization can be expensive.
1305 */
1306static void __init preallocate_vmalloc_pages(void)
1307{
1308	unsigned long addr;
1309	const char *lvl;
1310
1311	for (addr = VMALLOC_START; addr <= VMEMORY_END; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
1312		pgd_t *pgd = pgd_offset_k(addr);
1313		p4d_t *p4d;
1314		pud_t *pud;
1315
1316		lvl = "p4d";
1317		p4d = p4d_alloc(&init_mm, pgd, addr);
1318		if (!p4d)
1319			goto failed;
1320
1321		if (pgtable_l5_enabled())
1322			continue;
1323
1324		/*
1325		 * The goal here is to allocate all possibly required
1326		 * hardware page tables pointed to by the top hardware
1327		 * level.
1328		 *
1329		 * On 4-level systems, the P4D layer is folded away and
1330		 * the above code does no preallocation.  Below, go down
1331		 * to the pud _software_ level to ensure the second
1332		 * hardware level is allocated on 4-level systems too.
1333		 */
1334		lvl = "pud";
1335		pud = pud_alloc(&init_mm, p4d, addr);
1336		if (!pud)
1337			goto failed;
1338	}
1339
1340	return;
1341
1342failed:
1343
1344	/*
1345	 * The pages have to be there now or they will be missing in
1346	 * process page-tables later.
1347	 */
1348	panic("Failed to pre-allocate %s pages for vmalloc area\n", lvl);
1349}
1350
1351void __init mem_init(void)
1352{
1353	pci_iommu_alloc();
1354
1355	/* clear_bss() already clear the empty_zero_page */
1356
1357	/* this will put all memory onto the freelists */
1358	memblock_free_all();
1359	after_bootmem = 1;
1360	x86_init.hyper.init_after_bootmem();
1361
1362	/*
1363	 * Must be done after boot memory is put on freelist, because here we
1364	 * might set fields in deferred struct pages that have not yet been
1365	 * initialized, and memblock_free_all() initializes all the reserved
1366	 * deferred pages for us.
1367	 */
1368	register_page_bootmem_info();
1369
1370	/* Register memory areas for /proc/kcore */
1371	if (get_gate_vma(&init_mm))
1372		kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR, PAGE_SIZE, KCORE_USER);
1373
1374	preallocate_vmalloc_pages();
1375}
1376
1377int kernel_set_to_readonly;
1378
1379void mark_rodata_ro(void)
1380{
1381	unsigned long start = PFN_ALIGN(_text);
1382	unsigned long rodata_start = PFN_ALIGN(__start_rodata);
1383	unsigned long end = (unsigned long)__end_rodata_hpage_align;
1384	unsigned long text_end = PFN_ALIGN(_etext);
1385	unsigned long rodata_end = PFN_ALIGN(__end_rodata);
1386	unsigned long all_end;
1387
1388	printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
1389	       (end - start) >> 10);
1390	set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1391
1392	kernel_set_to_readonly = 1;
1393
1394	/*
1395	 * The rodata/data/bss/brk section (but not the kernel text!)
1396	 * should also be not-executable.
1397	 *
1398	 * We align all_end to PMD_SIZE because the existing mapping
1399	 * is a full PMD. If we would align _brk_end to PAGE_SIZE we
1400	 * split the PMD and the reminder between _brk_end and the end
1401	 * of the PMD will remain mapped executable.
1402	 *
1403	 * Any PMD which was setup after the one which covers _brk_end
1404	 * has been zapped already via cleanup_highmem().
1405	 */
1406	all_end = roundup((unsigned long)_brk_end, PMD_SIZE);
1407	set_memory_nx(text_end, (all_end - text_end) >> PAGE_SHIFT);
1408
1409	set_ftrace_ops_ro();
1410
1411#ifdef CONFIG_CPA_DEBUG
1412	printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
1413	set_memory_rw(start, (end-start) >> PAGE_SHIFT);
1414
1415	printk(KERN_INFO "Testing CPA: again\n");
1416	set_memory_ro(start, (end-start) >> PAGE_SHIFT);
1417#endif
1418
1419	free_kernel_image_pages("unused kernel image (text/rodata gap)",
1420				(void *)text_end, (void *)rodata_start);
1421	free_kernel_image_pages("unused kernel image (rodata/data gap)",
1422				(void *)rodata_end, (void *)_sdata);
1423}
1424
1425/*
1426 * Block size is the minimum amount of memory which can be hotplugged or
1427 * hotremoved. It must be power of two and must be equal or larger than
1428 * MIN_MEMORY_BLOCK_SIZE.
1429 */
1430#define MAX_BLOCK_SIZE (2UL << 30)
1431
1432/* Amount of ram needed to start using large blocks */
1433#define MEM_SIZE_FOR_LARGE_BLOCK (64UL << 30)
1434
1435/* Adjustable memory block size */
1436static unsigned long set_memory_block_size;
1437int __init set_memory_block_size_order(unsigned int order)
1438{
1439	unsigned long size = 1UL << order;
1440
1441	if (size > MEM_SIZE_FOR_LARGE_BLOCK || size < MIN_MEMORY_BLOCK_SIZE)
1442		return -EINVAL;
1443
1444	set_memory_block_size = size;
1445	return 0;
1446}
1447
1448static unsigned long probe_memory_block_size(void)
1449{
1450	unsigned long boot_mem_end = max_pfn << PAGE_SHIFT;
1451	unsigned long bz;
1452
1453	/* If memory block size has been set, then use it */
1454	bz = set_memory_block_size;
1455	if (bz)
1456		goto done;
1457
1458	/* Use regular block if RAM is smaller than MEM_SIZE_FOR_LARGE_BLOCK */
1459	if (boot_mem_end < MEM_SIZE_FOR_LARGE_BLOCK) {
1460		bz = MIN_MEMORY_BLOCK_SIZE;
1461		goto done;
1462	}
1463
1464	/*
1465	 * Use max block size to minimize overhead on bare metal, where
1466	 * alignment for memory hotplug isn't a concern.
1467	 */
1468	if (!boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
1469		bz = MAX_BLOCK_SIZE;
1470		goto done;
1471	}
1472
1473	/* Find the largest allowed block size that aligns to memory end */
1474	for (bz = MAX_BLOCK_SIZE; bz > MIN_MEMORY_BLOCK_SIZE; bz >>= 1) {
1475		if (IS_ALIGNED(boot_mem_end, bz))
1476			break;
1477	}
1478done:
1479	pr_info("x86/mm: Memory block size: %ldMB\n", bz >> 20);
1480
1481	return bz;
1482}
1483
1484static unsigned long memory_block_size_probed;
1485unsigned long memory_block_size_bytes(void)
1486{
1487	if (!memory_block_size_probed)
1488		memory_block_size_probed = probe_memory_block_size();
1489
1490	return memory_block_size_probed;
1491}
1492
1493#ifdef CONFIG_SPARSEMEM_VMEMMAP
1494/*
1495 * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1496 */
1497static long __meminitdata addr_start, addr_end;
1498static void __meminitdata *p_start, *p_end;
1499static int __meminitdata node_start;
1500
1501void __meminit vmemmap_set_pmd(pmd_t *pmd, void *p, int node,
1502			       unsigned long addr, unsigned long next)
1503{
1504	pte_t entry;
1505
1506	entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1507			PAGE_KERNEL_LARGE);
1508	set_pmd(pmd, __pmd(pte_val(entry)));
1509
1510	/* check to see if we have contiguous blocks */
1511	if (p_end != p || node_start != node) {
1512		if (p_start)
1513			pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1514				addr_start, addr_end-1, p_start, p_end-1, node_start);
1515		addr_start = addr;
1516		node_start = node;
1517		p_start = p;
1518	}
1519
1520	addr_end = addr + PMD_SIZE;
1521	p_end = p + PMD_SIZE;
1522
1523	if (!IS_ALIGNED(addr, PMD_SIZE) ||
1524		!IS_ALIGNED(next, PMD_SIZE))
1525		vmemmap_use_new_sub_pmd(addr, next);
1526}
1527
1528int __meminit vmemmap_check_pmd(pmd_t *pmd, int node,
1529				unsigned long addr, unsigned long next)
1530{
1531	int large = pmd_leaf(*pmd);
1532
1533	if (pmd_leaf(*pmd)) {
1534		vmemmap_verify((pte_t *)pmd, node, addr, next);
1535		vmemmap_use_sub_pmd(addr, next);
1536	}
1537
1538	return large;
1539}
1540
1541int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
1542		struct vmem_altmap *altmap)
1543{
1544	int err;
1545
1546	VM_BUG_ON(!PAGE_ALIGNED(start));
1547	VM_BUG_ON(!PAGE_ALIGNED(end));
1548
1549	if (end - start < PAGES_PER_SECTION * sizeof(struct page))
1550		err = vmemmap_populate_basepages(start, end, node, NULL);
1551	else if (boot_cpu_has(X86_FEATURE_PSE))
1552		err = vmemmap_populate_hugepages(start, end, node, altmap);
1553	else if (altmap) {
1554		pr_err_once("%s: no cpu support for altmap allocations\n",
1555				__func__);
1556		err = -ENOMEM;
1557	} else
1558		err = vmemmap_populate_basepages(start, end, node, NULL);
1559	if (!err)
1560		sync_global_pgds(start, end - 1);
1561	return err;
1562}
1563
1564#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
1565void register_page_bootmem_memmap(unsigned long section_nr,
1566				  struct page *start_page, unsigned long nr_pages)
1567{
1568	unsigned long addr = (unsigned long)start_page;
1569	unsigned long end = (unsigned long)(start_page + nr_pages);
1570	unsigned long next;
1571	pgd_t *pgd;
1572	p4d_t *p4d;
1573	pud_t *pud;
1574	pmd_t *pmd;
1575	unsigned int nr_pmd_pages;
1576	struct page *page;
1577
1578	for (; addr < end; addr = next) {
1579		pte_t *pte = NULL;
1580
1581		pgd = pgd_offset_k(addr);
1582		if (pgd_none(*pgd)) {
1583			next = (addr + PAGE_SIZE) & PAGE_MASK;
1584			continue;
1585		}
1586		get_page_bootmem(section_nr, pgd_page(*pgd), MIX_SECTION_INFO);
1587
1588		p4d = p4d_offset(pgd, addr);
1589		if (p4d_none(*p4d)) {
1590			next = (addr + PAGE_SIZE) & PAGE_MASK;
1591			continue;
1592		}
1593		get_page_bootmem(section_nr, p4d_page(*p4d), MIX_SECTION_INFO);
1594
1595		pud = pud_offset(p4d, addr);
1596		if (pud_none(*pud)) {
1597			next = (addr + PAGE_SIZE) & PAGE_MASK;
1598			continue;
1599		}
1600		get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO);
1601
1602		if (!boot_cpu_has(X86_FEATURE_PSE)) {
1603			next = (addr + PAGE_SIZE) & PAGE_MASK;
1604			pmd = pmd_offset(pud, addr);
1605			if (pmd_none(*pmd))
1606				continue;
1607			get_page_bootmem(section_nr, pmd_page(*pmd),
1608					 MIX_SECTION_INFO);
1609
1610			pte = pte_offset_kernel(pmd, addr);
1611			if (pte_none(*pte))
1612				continue;
1613			get_page_bootmem(section_nr, pte_page(*pte),
1614					 SECTION_INFO);
1615		} else {
1616			next = pmd_addr_end(addr, end);
1617
1618			pmd = pmd_offset(pud, addr);
1619			if (pmd_none(*pmd))
1620				continue;
1621
1622			nr_pmd_pages = 1 << get_order(PMD_SIZE);
1623			page = pmd_page(*pmd);
1624			while (nr_pmd_pages--)
1625				get_page_bootmem(section_nr, page++,
1626						 SECTION_INFO);
1627		}
1628	}
1629}
1630#endif
1631
1632void __meminit vmemmap_populate_print_last(void)
1633{
1634	if (p_start) {
1635		pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1636			addr_start, addr_end-1, p_start, p_end-1, node_start);
1637		p_start = NULL;
1638		p_end = NULL;
1639		node_start = 0;
1640	}
1641}
1642#endif