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Linux/arch/x86/mm/init_64.c

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  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/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 
 37 #include <asm/processor.h>
 38 #include <asm/bios_ebda.h>
 39 #include <linux/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/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 
 58 #include "mm_internal.h"
 59 
 60 #include "ident_map.c"
 61 
 62 /*
 63  * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
 64  * physical space so we can cache the place of the first one and move
 65  * around without checking the pgd every time.
 66  */
 67 
 68 /* Bits supported by the hardware: */
 69 pteval_t __supported_pte_mask __read_mostly = ~0;
 70 /* Bits allowed in normal kernel mappings: */
 71 pteval_t __default_kernel_pte_mask __read_mostly = ~0;
 72 EXPORT_SYMBOL_GPL(__supported_pte_mask);
 73 /* Used in PAGE_KERNEL_* macros which are reasonably used out-of-tree: */
 74 EXPORT_SYMBOL(__default_kernel_pte_mask);
 75 
 76 int force_personality32;
 77 
 78 /*
 79  * noexec32=on|off
 80  * Control non executable heap for 32bit processes.
 81  * To control the stack too use noexec=off
 82  *
 83  * on   PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
 84  * off  PROT_READ implies PROT_EXEC
 85  */
 86 static int __init nonx32_setup(char *str)
 87 {
 88         if (!strcmp(str, "on"))
 89                 force_personality32 &= ~READ_IMPLIES_EXEC;
 90         else if (!strcmp(str, "off"))
 91                 force_personality32 |= READ_IMPLIES_EXEC;
 92         return 1;
 93 }
 94 __setup("noexec32=", nonx32_setup);
 95 
 96 static void sync_global_pgds_l5(unsigned long start, unsigned long end)
 97 {
 98         unsigned long addr;
 99 
100         for (addr = start; addr <= end; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
101                 const pgd_t *pgd_ref = pgd_offset_k(addr);
102                 struct page *page;
103 
104                 /* Check for overflow */
105                 if (addr < start)
106                         break;
107 
108                 if (pgd_none(*pgd_ref))
109                         continue;
110 
111                 spin_lock(&pgd_lock);
112                 list_for_each_entry(page, &pgd_list, lru) {
113                         pgd_t *pgd;
114                         spinlock_t *pgt_lock;
115 
116                         pgd = (pgd_t *)page_address(page) + pgd_index(addr);
117                         /* the pgt_lock only for Xen */
118                         pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
119                         spin_lock(pgt_lock);
120 
121                         if (!pgd_none(*pgd_ref) && !pgd_none(*pgd))
122                                 BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref));
123 
124                         if (pgd_none(*pgd))
125                                 set_pgd(pgd, *pgd_ref);
126 
127                         spin_unlock(pgt_lock);
128                 }
129                 spin_unlock(&pgd_lock);
130         }
131 }
132 
133 static void sync_global_pgds_l4(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                 pgd_t *pgd_ref = pgd_offset_k(addr);
139                 const p4d_t *p4d_ref;
140                 struct page *page;
141 
142                 /*
143                  * With folded p4d, pgd_none() is always false, we need to
144                  * handle synchonization on p4d level.
145                  */
146                 MAYBE_BUILD_BUG_ON(pgd_none(*pgd_ref));
147                 p4d_ref = p4d_offset(pgd_ref, addr);
148 
149                 if (p4d_none(*p4d_ref))
150                         continue;
151 
152                 spin_lock(&pgd_lock);
153                 list_for_each_entry(page, &pgd_list, lru) {
154                         pgd_t *pgd;
155                         p4d_t *p4d;
156                         spinlock_t *pgt_lock;
157 
158                         pgd = (pgd_t *)page_address(page) + pgd_index(addr);
159                         p4d = p4d_offset(pgd, addr);
160                         /* the pgt_lock only for Xen */
161                         pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
162                         spin_lock(pgt_lock);
163 
164                         if (!p4d_none(*p4d_ref) && !p4d_none(*p4d))
165                                 BUG_ON(p4d_page_vaddr(*p4d)
166                                        != p4d_page_vaddr(*p4d_ref));
167 
168                         if (p4d_none(*p4d))
169                                 set_p4d(p4d, *p4d_ref);
170 
171                         spin_unlock(pgt_lock);
172                 }
173                 spin_unlock(&pgd_lock);
174         }
175 }
176 
177 /*
178  * When memory was added make sure all the processes MM have
179  * suitable PGD entries in the local PGD level page.
180  */
181 void sync_global_pgds(unsigned long start, unsigned long end)
182 {
183         if (pgtable_l5_enabled())
184                 sync_global_pgds_l5(start, end);
185         else
186                 sync_global_pgds_l4(start, end);
187 }
188 
189 /*
190  * NOTE: This function is marked __ref because it calls __init function
191  * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
192  */
193 static __ref void *spp_getpage(void)
194 {
195         void *ptr;
196 
197         if (after_bootmem)
198                 ptr = (void *) get_zeroed_page(GFP_ATOMIC);
199         else
200                 ptr = alloc_bootmem_pages(PAGE_SIZE);
201 
202         if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
203                 panic("set_pte_phys: cannot allocate page data %s\n",
204                         after_bootmem ? "after bootmem" : "");
205         }
206 
207         pr_debug("spp_getpage %p\n", ptr);
208 
209         return ptr;
210 }
211 
212 static p4d_t *fill_p4d(pgd_t *pgd, unsigned long vaddr)
213 {
214         if (pgd_none(*pgd)) {
215                 p4d_t *p4d = (p4d_t *)spp_getpage();
216                 pgd_populate(&init_mm, pgd, p4d);
217                 if (p4d != p4d_offset(pgd, 0))
218                         printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n",
219                                p4d, p4d_offset(pgd, 0));
220         }
221         return p4d_offset(pgd, vaddr);
222 }
223 
224 static pud_t *fill_pud(p4d_t *p4d, unsigned long vaddr)
225 {
226         if (p4d_none(*p4d)) {
227                 pud_t *pud = (pud_t *)spp_getpage();
228                 p4d_populate(&init_mm, p4d, pud);
229                 if (pud != pud_offset(p4d, 0))
230                         printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
231                                pud, pud_offset(p4d, 0));
232         }
233         return pud_offset(p4d, vaddr);
234 }
235 
236 static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr)
237 {
238         if (pud_none(*pud)) {
239                 pmd_t *pmd = (pmd_t *) spp_getpage();
240                 pud_populate(&init_mm, pud, pmd);
241                 if (pmd != pmd_offset(pud, 0))
242                         printk(KERN_ERR "PAGETABLE BUG #02! %p <-> %p\n",
243                                pmd, pmd_offset(pud, 0));
244         }
245         return pmd_offset(pud, vaddr);
246 }
247 
248 static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr)
249 {
250         if (pmd_none(*pmd)) {
251                 pte_t *pte = (pte_t *) spp_getpage();
252                 pmd_populate_kernel(&init_mm, pmd, pte);
253                 if (pte != pte_offset_kernel(pmd, 0))
254                         printk(KERN_ERR "PAGETABLE BUG #03!\n");
255         }
256         return pte_offset_kernel(pmd, vaddr);
257 }
258 
259 static void __set_pte_vaddr(pud_t *pud, unsigned long vaddr, pte_t new_pte)
260 {
261         pmd_t *pmd = fill_pmd(pud, vaddr);
262         pte_t *pte = fill_pte(pmd, vaddr);
263 
264         set_pte(pte, new_pte);
265 
266         /*
267          * It's enough to flush this one mapping.
268          * (PGE mappings get flushed as well)
269          */
270         __flush_tlb_one_kernel(vaddr);
271 }
272 
273 void set_pte_vaddr_p4d(p4d_t *p4d_page, unsigned long vaddr, pte_t new_pte)
274 {
275         p4d_t *p4d = p4d_page + p4d_index(vaddr);
276         pud_t *pud = fill_pud(p4d, vaddr);
277 
278         __set_pte_vaddr(pud, vaddr, new_pte);
279 }
280 
281 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
282 {
283         pud_t *pud = pud_page + pud_index(vaddr);
284 
285         __set_pte_vaddr(pud, vaddr, new_pte);
286 }
287 
288 void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
289 {
290         pgd_t *pgd;
291         p4d_t *p4d_page;
292 
293         pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
294 
295         pgd = pgd_offset_k(vaddr);
296         if (pgd_none(*pgd)) {
297                 printk(KERN_ERR
298                         "PGD FIXMAP MISSING, it should be setup in head.S!\n");
299                 return;
300         }
301 
302         p4d_page = p4d_offset(pgd, 0);
303         set_pte_vaddr_p4d(p4d_page, vaddr, pteval);
304 }
305 
306 pmd_t * __init populate_extra_pmd(unsigned long vaddr)
307 {
308         pgd_t *pgd;
309         p4d_t *p4d;
310         pud_t *pud;
311 
312         pgd = pgd_offset_k(vaddr);
313         p4d = fill_p4d(pgd, vaddr);
314         pud = fill_pud(p4d, vaddr);
315         return fill_pmd(pud, vaddr);
316 }
317 
318 pte_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  */
329 static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
330                                         enum page_cache_mode cache)
331 {
332         pgd_t *pgd;
333         p4d_t *p4d;
334         pud_t *pud;
335         pmd_t *pmd;
336         pgprot_t prot;
337 
338         pgprot_val(prot) = pgprot_val(PAGE_KERNEL_LARGE) |
339                 pgprot_val(pgprot_4k_2_large(cachemode2pgprot(cache)));
340         BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
341         for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
342                 pgd = pgd_offset_k((unsigned long)__va(phys));
343                 if (pgd_none(*pgd)) {
344                         p4d = (p4d_t *) spp_getpage();
345                         set_pgd(pgd, __pgd(__pa(p4d) | _KERNPG_TABLE |
346                                                 _PAGE_USER));
347                 }
348                 p4d = p4d_offset(pgd, (unsigned long)__va(phys));
349                 if (p4d_none(*p4d)) {
350                         pud = (pud_t *) spp_getpage();
351                         set_p4d(p4d, __p4d(__pa(pud) | _KERNPG_TABLE |
352                                                 _PAGE_USER));
353                 }
354                 pud = pud_offset(p4d, (unsigned long)__va(phys));
355                 if (pud_none(*pud)) {
356                         pmd = (pmd_t *) spp_getpage();
357                         set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
358                                                 _PAGE_USER));
359                 }
360                 pmd = pmd_offset(pud, phys);
361                 BUG_ON(!pmd_none(*pmd));
362                 set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
363         }
364 }
365 
366 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
367 {
368         __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_WB);
369 }
370 
371 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
372 {
373         __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_UC);
374 }
375 
376 /*
377  * The head.S code sets up the kernel high mapping:
378  *
379  *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
380  *
381  * phys_base holds the negative offset to the kernel, which is added
382  * to the compile time generated pmds. This results in invalid pmds up
383  * to the point where we hit the physaddr 0 mapping.
384  *
385  * We limit the mappings to the region from _text to _brk_end.  _brk_end
386  * is rounded up to the 2MB boundary. This catches the invalid pmds as
387  * well, as they are located before _text:
388  */
389 void __init cleanup_highmap(void)
390 {
391         unsigned long vaddr = __START_KERNEL_map;
392         unsigned long vaddr_end = __START_KERNEL_map + KERNEL_IMAGE_SIZE;
393         unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1;
394         pmd_t *pmd = level2_kernel_pgt;
395 
396         /*
397          * Native path, max_pfn_mapped is not set yet.
398          * Xen has valid max_pfn_mapped set in
399          *      arch/x86/xen/mmu.c:xen_setup_kernel_pagetable().
400          */
401         if (max_pfn_mapped)
402                 vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT);
403 
404         for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) {
405                 if (pmd_none(*pmd))
406                         continue;
407                 if (vaddr < (unsigned long) _text || vaddr > end)
408                         set_pmd(pmd, __pmd(0));
409         }
410 }
411 
412 /*
413  * Create PTE level page table mapping for physical addresses.
414  * It returns the last physical address mapped.
415  */
416 static unsigned long __meminit
417 phys_pte_init(pte_t *pte_page, unsigned long paddr, unsigned long paddr_end,
418               pgprot_t prot)
419 {
420         unsigned long pages = 0, paddr_next;
421         unsigned long paddr_last = paddr_end;
422         pte_t *pte;
423         int i;
424 
425         pte = pte_page + pte_index(paddr);
426         i = pte_index(paddr);
427 
428         for (; i < PTRS_PER_PTE; i++, paddr = paddr_next, pte++) {
429                 paddr_next = (paddr & PAGE_MASK) + PAGE_SIZE;
430                 if (paddr >= paddr_end) {
431                         if (!after_bootmem &&
432                             !e820__mapped_any(paddr & PAGE_MASK, paddr_next,
433                                              E820_TYPE_RAM) &&
434                             !e820__mapped_any(paddr & PAGE_MASK, paddr_next,
435                                              E820_TYPE_RESERVED_KERN))
436                                 set_pte(pte, __pte(0));
437                         continue;
438                 }
439 
440                 /*
441                  * We will re-use the existing mapping.
442                  * Xen for example has some special requirements, like mapping
443                  * pagetable pages as RO. So assume someone who pre-setup
444                  * these mappings are more intelligent.
445                  */
446                 if (!pte_none(*pte)) {
447                         if (!after_bootmem)
448                                 pages++;
449                         continue;
450                 }
451 
452                 if (0)
453                         pr_info("   pte=%p addr=%lx pte=%016lx\n", pte, paddr,
454                                 pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL).pte);
455                 pages++;
456                 set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, prot));
457                 paddr_last = (paddr & PAGE_MASK) + PAGE_SIZE;
458         }
459 
460         update_page_count(PG_LEVEL_4K, pages);
461 
462         return paddr_last;
463 }
464 
465 /*
466  * Create PMD level page table mapping for physical addresses. The virtual
467  * and physical address have to be aligned at this level.
468  * It returns the last physical address mapped.
469  */
470 static unsigned long __meminit
471 phys_pmd_init(pmd_t *pmd_page, unsigned long paddr, unsigned long paddr_end,
472               unsigned long page_size_mask, pgprot_t prot)
473 {
474         unsigned long pages = 0, paddr_next;
475         unsigned long paddr_last = paddr_end;
476 
477         int i = pmd_index(paddr);
478 
479         for (; i < PTRS_PER_PMD; i++, paddr = paddr_next) {
480                 pmd_t *pmd = pmd_page + pmd_index(paddr);
481                 pte_t *pte;
482                 pgprot_t new_prot = prot;
483 
484                 paddr_next = (paddr & PMD_MASK) + PMD_SIZE;
485                 if (paddr >= paddr_end) {
486                         if (!after_bootmem &&
487                             !e820__mapped_any(paddr & PMD_MASK, paddr_next,
488                                              E820_TYPE_RAM) &&
489                             !e820__mapped_any(paddr & PMD_MASK, paddr_next,
490                                              E820_TYPE_RESERVED_KERN))
491                                 set_pmd(pmd, __pmd(0));
492                         continue;
493                 }
494 
495                 if (!pmd_none(*pmd)) {
496                         if (!pmd_large(*pmd)) {
497                                 spin_lock(&init_mm.page_table_lock);
498                                 pte = (pte_t *)pmd_page_vaddr(*pmd);
499                                 paddr_last = phys_pte_init(pte, paddr,
500                                                            paddr_end, prot);
501                                 spin_unlock(&init_mm.page_table_lock);
502                                 continue;
503                         }
504                         /*
505                          * If we are ok with PG_LEVEL_2M mapping, then we will
506                          * use the existing mapping,
507                          *
508                          * Otherwise, we will split the large page mapping but
509                          * use the same existing protection bits except for
510                          * large page, so that we don't violate Intel's TLB
511                          * Application note (317080) which says, while changing
512                          * the page sizes, new and old translations should
513                          * not differ with respect to page frame and
514                          * attributes.
515                          */
516                         if (page_size_mask & (1 << PG_LEVEL_2M)) {
517                                 if (!after_bootmem)
518                                         pages++;
519                                 paddr_last = paddr_next;
520                                 continue;
521                         }
522                         new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
523                 }
524 
525                 if (page_size_mask & (1<<PG_LEVEL_2M)) {
526                         pages++;
527                         spin_lock(&init_mm.page_table_lock);
528                         set_pte((pte_t *)pmd,
529                                 pfn_pte((paddr & PMD_MASK) >> PAGE_SHIFT,
530                                         __pgprot(pgprot_val(prot) | _PAGE_PSE)));
531                         spin_unlock(&init_mm.page_table_lock);
532                         paddr_last = paddr_next;
533                         continue;
534                 }
535 
536                 pte = alloc_low_page();
537                 paddr_last = phys_pte_init(pte, paddr, paddr_end, new_prot);
538 
539                 spin_lock(&init_mm.page_table_lock);
540                 pmd_populate_kernel(&init_mm, pmd, pte);
541                 spin_unlock(&init_mm.page_table_lock);
542         }
543         update_page_count(PG_LEVEL_2M, pages);
544         return paddr_last;
545 }
546 
547 /*
548  * Create PUD level page table mapping for physical addresses. The virtual
549  * and physical address do not have to be aligned at this level. KASLR can
550  * randomize virtual addresses up to this level.
551  * It returns the last physical address mapped.
552  */
553 static unsigned long __meminit
554 phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end,
555               unsigned long page_size_mask)
556 {
557         unsigned long pages = 0, paddr_next;
558         unsigned long paddr_last = paddr_end;
559         unsigned long vaddr = (unsigned long)__va(paddr);
560         int i = pud_index(vaddr);
561 
562         for (; i < PTRS_PER_PUD; i++, paddr = paddr_next) {
563                 pud_t *pud;
564                 pmd_t *pmd;
565                 pgprot_t prot = PAGE_KERNEL;
566 
567                 vaddr = (unsigned long)__va(paddr);
568                 pud = pud_page + pud_index(vaddr);
569                 paddr_next = (paddr & PUD_MASK) + PUD_SIZE;
570 
571                 if (paddr >= paddr_end) {
572                         if (!after_bootmem &&
573                             !e820__mapped_any(paddr & PUD_MASK, paddr_next,
574                                              E820_TYPE_RAM) &&
575                             !e820__mapped_any(paddr & PUD_MASK, paddr_next,
576                                              E820_TYPE_RESERVED_KERN))
577                                 set_pud(pud, __pud(0));
578                         continue;
579                 }
580 
581                 if (!pud_none(*pud)) {
582                         if (!pud_large(*pud)) {
583                                 pmd = pmd_offset(pud, 0);
584                                 paddr_last = phys_pmd_init(pmd, paddr,
585                                                            paddr_end,
586                                                            page_size_mask,
587                                                            prot);
588                                 __flush_tlb_all();
589                                 continue;
590                         }
591                         /*
592                          * If we are ok with PG_LEVEL_1G mapping, then we will
593                          * use the existing mapping.
594                          *
595                          * Otherwise, we will split the gbpage mapping but use
596                          * the same existing protection  bits except for large
597                          * page, so that we don't violate Intel's TLB
598                          * Application note (317080) which says, while changing
599                          * the page sizes, new and old translations should
600                          * not differ with respect to page frame and
601                          * attributes.
602                          */
603                         if (page_size_mask & (1 << PG_LEVEL_1G)) {
604                                 if (!after_bootmem)
605                                         pages++;
606                                 paddr_last = paddr_next;
607                                 continue;
608                         }
609                         prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
610                 }
611 
612                 if (page_size_mask & (1<<PG_LEVEL_1G)) {
613                         pages++;
614                         spin_lock(&init_mm.page_table_lock);
615                         set_pte((pte_t *)pud,
616                                 pfn_pte((paddr & PUD_MASK) >> PAGE_SHIFT,
617                                         PAGE_KERNEL_LARGE));
618                         spin_unlock(&init_mm.page_table_lock);
619                         paddr_last = paddr_next;
620                         continue;
621                 }
622 
623                 pmd = alloc_low_page();
624                 paddr_last = phys_pmd_init(pmd, paddr, paddr_end,
625                                            page_size_mask, prot);
626 
627                 spin_lock(&init_mm.page_table_lock);
628                 pud_populate(&init_mm, pud, pmd);
629                 spin_unlock(&init_mm.page_table_lock);
630         }
631         __flush_tlb_all();
632 
633         update_page_count(PG_LEVEL_1G, pages);
634 
635         return paddr_last;
636 }
637 
638 static unsigned long __meminit
639 phys_p4d_init(p4d_t *p4d_page, unsigned long paddr, unsigned long paddr_end,
640               unsigned long page_size_mask)
641 {
642         unsigned long paddr_next, paddr_last = paddr_end;
643         unsigned long vaddr = (unsigned long)__va(paddr);
644         int i = p4d_index(vaddr);
645 
646         if (!pgtable_l5_enabled())
647                 return phys_pud_init((pud_t *) p4d_page, paddr, paddr_end, page_size_mask);
648 
649         for (; i < PTRS_PER_P4D; i++, paddr = paddr_next) {
650                 p4d_t *p4d;
651                 pud_t *pud;
652 
653                 vaddr = (unsigned long)__va(paddr);
654                 p4d = p4d_page + p4d_index(vaddr);
655                 paddr_next = (paddr & P4D_MASK) + P4D_SIZE;
656 
657                 if (paddr >= paddr_end) {
658                         if (!after_bootmem &&
659                             !e820__mapped_any(paddr & P4D_MASK, paddr_next,
660                                              E820_TYPE_RAM) &&
661                             !e820__mapped_any(paddr & P4D_MASK, paddr_next,
662                                              E820_TYPE_RESERVED_KERN))
663                                 set_p4d(p4d, __p4d(0));
664                         continue;
665                 }
666 
667                 if (!p4d_none(*p4d)) {
668                         pud = pud_offset(p4d, 0);
669                         paddr_last = phys_pud_init(pud, paddr,
670                                         paddr_end,
671                                         page_size_mask);
672                         __flush_tlb_all();
673                         continue;
674                 }
675 
676                 pud = alloc_low_page();
677                 paddr_last = phys_pud_init(pud, paddr, paddr_end,
678                                            page_size_mask);
679 
680                 spin_lock(&init_mm.page_table_lock);
681                 p4d_populate(&init_mm, p4d, pud);
682                 spin_unlock(&init_mm.page_table_lock);
683         }
684         __flush_tlb_all();
685 
686         return paddr_last;
687 }
688 
689 /*
690  * Create page table mapping for the physical memory for specific physical
691  * addresses. The virtual and physical addresses have to be aligned on PMD level
692  * down. It returns the last physical address mapped.
693  */
694 unsigned long __meminit
695 kernel_physical_mapping_init(unsigned long paddr_start,
696                              unsigned long paddr_end,
697                              unsigned long page_size_mask)
698 {
699         bool pgd_changed = false;
700         unsigned long vaddr, vaddr_start, vaddr_end, vaddr_next, paddr_last;
701 
702         paddr_last = paddr_end;
703         vaddr = (unsigned long)__va(paddr_start);
704         vaddr_end = (unsigned long)__va(paddr_end);
705         vaddr_start = vaddr;
706 
707         for (; vaddr < vaddr_end; vaddr = vaddr_next) {
708                 pgd_t *pgd = pgd_offset_k(vaddr);
709                 p4d_t *p4d;
710 
711                 vaddr_next = (vaddr & PGDIR_MASK) + PGDIR_SIZE;
712 
713                 if (pgd_val(*pgd)) {
714                         p4d = (p4d_t *)pgd_page_vaddr(*pgd);
715                         paddr_last = phys_p4d_init(p4d, __pa(vaddr),
716                                                    __pa(vaddr_end),
717                                                    page_size_mask);
718                         continue;
719                 }
720 
721                 p4d = alloc_low_page();
722                 paddr_last = phys_p4d_init(p4d, __pa(vaddr), __pa(vaddr_end),
723                                            page_size_mask);
724 
725                 spin_lock(&init_mm.page_table_lock);
726                 if (pgtable_l5_enabled())
727                         pgd_populate(&init_mm, pgd, p4d);
728                 else
729                         p4d_populate(&init_mm, p4d_offset(pgd, vaddr), (pud_t *) p4d);
730                 spin_unlock(&init_mm.page_table_lock);
731                 pgd_changed = true;
732         }
733 
734         if (pgd_changed)
735                 sync_global_pgds(vaddr_start, vaddr_end - 1);
736 
737         __flush_tlb_all();
738 
739         return paddr_last;
740 }
741 
742 #ifndef CONFIG_NUMA
743 void __init initmem_init(void)
744 {
745         memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
746 }
747 #endif
748 
749 void __init paging_init(void)
750 {
751         sparse_memory_present_with_active_regions(MAX_NUMNODES);
752         sparse_init();
753 
754         /*
755          * clear the default setting with node 0
756          * note: don't use nodes_clear here, that is really clearing when
757          *       numa support is not compiled in, and later node_set_state
758          *       will not set it back.
759          */
760         node_clear_state(0, N_MEMORY);
761         if (N_MEMORY != N_NORMAL_MEMORY)
762                 node_clear_state(0, N_NORMAL_MEMORY);
763 
764         zone_sizes_init();
765 }
766 
767 /*
768  * Memory hotplug specific functions
769  */
770 #ifdef CONFIG_MEMORY_HOTPLUG
771 /*
772  * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
773  * updating.
774  */
775 static void update_end_of_memory_vars(u64 start, u64 size)
776 {
777         unsigned long end_pfn = PFN_UP(start + size);
778 
779         if (end_pfn > max_pfn) {
780                 max_pfn = end_pfn;
781                 max_low_pfn = end_pfn;
782                 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
783         }
784 }
785 
786 int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
787                 struct vmem_altmap *altmap, bool want_memblock)
788 {
789         int ret;
790 
791         ret = __add_pages(nid, start_pfn, nr_pages, altmap, want_memblock);
792         WARN_ON_ONCE(ret);
793 
794         /* update max_pfn, max_low_pfn and high_memory */
795         update_end_of_memory_vars(start_pfn << PAGE_SHIFT,
796                                   nr_pages << PAGE_SHIFT);
797 
798         return ret;
799 }
800 
801 int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
802                 bool want_memblock)
803 {
804         unsigned long start_pfn = start >> PAGE_SHIFT;
805         unsigned long nr_pages = size >> PAGE_SHIFT;
806 
807         init_memory_mapping(start, start + size);
808 
809         return add_pages(nid, start_pfn, nr_pages, altmap, want_memblock);
810 }
811 
812 #define PAGE_INUSE 0xFD
813 
814 static void __meminit free_pagetable(struct page *page, int order)
815 {
816         unsigned long magic;
817         unsigned int nr_pages = 1 << order;
818 
819         /* bootmem page has reserved flag */
820         if (PageReserved(page)) {
821                 __ClearPageReserved(page);
822 
823                 magic = (unsigned long)page->freelist;
824                 if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
825                         while (nr_pages--)
826                                 put_page_bootmem(page++);
827                 } else
828                         while (nr_pages--)
829                                 free_reserved_page(page++);
830         } else
831                 free_pages((unsigned long)page_address(page), order);
832 }
833 
834 static void __meminit free_hugepage_table(struct page *page,
835                 struct vmem_altmap *altmap)
836 {
837         if (altmap)
838                 vmem_altmap_free(altmap, PMD_SIZE / PAGE_SIZE);
839         else
840                 free_pagetable(page, get_order(PMD_SIZE));
841 }
842 
843 static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
844 {
845         pte_t *pte;
846         int i;
847 
848         for (i = 0; i < PTRS_PER_PTE; i++) {
849                 pte = pte_start + i;
850                 if (!pte_none(*pte))
851                         return;
852         }
853 
854         /* free a pte talbe */
855         free_pagetable(pmd_page(*pmd), 0);
856         spin_lock(&init_mm.page_table_lock);
857         pmd_clear(pmd);
858         spin_unlock(&init_mm.page_table_lock);
859 }
860 
861 static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
862 {
863         pmd_t *pmd;
864         int i;
865 
866         for (i = 0; i < PTRS_PER_PMD; i++) {
867                 pmd = pmd_start + i;
868                 if (!pmd_none(*pmd))
869                         return;
870         }
871 
872         /* free a pmd talbe */
873         free_pagetable(pud_page(*pud), 0);
874         spin_lock(&init_mm.page_table_lock);
875         pud_clear(pud);
876         spin_unlock(&init_mm.page_table_lock);
877 }
878 
879 static void __meminit free_pud_table(pud_t *pud_start, p4d_t *p4d)
880 {
881         pud_t *pud;
882         int i;
883 
884         for (i = 0; i < PTRS_PER_PUD; i++) {
885                 pud = pud_start + i;
886                 if (!pud_none(*pud))
887                         return;
888         }
889 
890         /* free a pud talbe */
891         free_pagetable(p4d_page(*p4d), 0);
892         spin_lock(&init_mm.page_table_lock);
893         p4d_clear(p4d);
894         spin_unlock(&init_mm.page_table_lock);
895 }
896 
897 static void __meminit
898 remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
899                  bool direct)
900 {
901         unsigned long next, pages = 0;
902         pte_t *pte;
903         void *page_addr;
904         phys_addr_t phys_addr;
905 
906         pte = pte_start + pte_index(addr);
907         for (; addr < end; addr = next, pte++) {
908                 next = (addr + PAGE_SIZE) & PAGE_MASK;
909                 if (next > end)
910                         next = end;
911 
912                 if (!pte_present(*pte))
913                         continue;
914 
915                 /*
916                  * We mapped [0,1G) memory as identity mapping when
917                  * initializing, in arch/x86/kernel/head_64.S. These
918                  * pagetables cannot be removed.
919                  */
920                 phys_addr = pte_val(*pte) + (addr & PAGE_MASK);
921                 if (phys_addr < (phys_addr_t)0x40000000)
922                         return;
923 
924                 if (PAGE_ALIGNED(addr) && PAGE_ALIGNED(next)) {
925                         /*
926                          * Do not free direct mapping pages since they were
927                          * freed when offlining, or simplely not in use.
928                          */
929                         if (!direct)
930                                 free_pagetable(pte_page(*pte), 0);
931 
932                         spin_lock(&init_mm.page_table_lock);
933                         pte_clear(&init_mm, addr, pte);
934                         spin_unlock(&init_mm.page_table_lock);
935 
936                         /* For non-direct mapping, pages means nothing. */
937                         pages++;
938                 } else {
939                         /*
940                          * If we are here, we are freeing vmemmap pages since
941                          * direct mapped memory ranges to be freed are aligned.
942                          *
943                          * If we are not removing the whole page, it means
944                          * other page structs in this page are being used and
945                          * we canot remove them. So fill the unused page_structs
946                          * with 0xFD, and remove the page when it is wholly
947                          * filled with 0xFD.
948                          */
949                         memset((void *)addr, PAGE_INUSE, next - addr);
950 
951                         page_addr = page_address(pte_page(*pte));
952                         if (!memchr_inv(page_addr, PAGE_INUSE, PAGE_SIZE)) {
953                                 free_pagetable(pte_page(*pte), 0);
954 
955                                 spin_lock(&init_mm.page_table_lock);
956                                 pte_clear(&init_mm, addr, pte);
957                                 spin_unlock(&init_mm.page_table_lock);
958                         }
959                 }
960         }
961 
962         /* Call free_pte_table() in remove_pmd_table(). */
963         flush_tlb_all();
964         if (direct)
965                 update_page_count(PG_LEVEL_4K, -pages);
966 }
967 
968 static void __meminit
969 remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
970                  bool direct, struct vmem_altmap *altmap)
971 {
972         unsigned long next, pages = 0;
973         pte_t *pte_base;
974         pmd_t *pmd;
975         void *page_addr;
976 
977         pmd = pmd_start + pmd_index(addr);
978         for (; addr < end; addr = next, pmd++) {
979                 next = pmd_addr_end(addr, end);
980 
981                 if (!pmd_present(*pmd))
982                         continue;
983 
984                 if (pmd_large(*pmd)) {
985                         if (IS_ALIGNED(addr, PMD_SIZE) &&
986                             IS_ALIGNED(next, PMD_SIZE)) {
987                                 if (!direct)
988                                         free_hugepage_table(pmd_page(*pmd),
989                                                             altmap);
990 
991                                 spin_lock(&init_mm.page_table_lock);
992                                 pmd_clear(pmd);
993                                 spin_unlock(&init_mm.page_table_lock);
994                                 pages++;
995                         } else {
996                                 /* If here, we are freeing vmemmap pages. */
997                                 memset((void *)addr, PAGE_INUSE, next - addr);
998 
999                                 page_addr = page_address(pmd_page(*pmd));
1000                                 if (!memchr_inv(page_addr, PAGE_INUSE,
1001                                                 PMD_SIZE)) {
1002                                         free_hugepage_table(pmd_page(*pmd),
1003                                                             altmap);
1004 
1005                                         spin_lock(&init_mm.page_table_lock);
1006                                         pmd_clear(pmd);
1007                                         spin_unlock(&init_mm.page_table_lock);
1008                                 }
1009                         }
1010 
1011                         continue;
1012                 }
1013 
1014                 pte_base = (pte_t *)pmd_page_vaddr(*pmd);
1015                 remove_pte_table(pte_base, addr, next, direct);
1016                 free_pte_table(pte_base, pmd);
1017         }
1018 
1019         /* Call free_pmd_table() in remove_pud_table(). */
1020         if (direct)
1021                 update_page_count(PG_LEVEL_2M, -pages);
1022 }
1023 
1024 static void __meminit
1025 remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
1026                  struct vmem_altmap *altmap, bool direct)
1027 {
1028         unsigned long next, pages = 0;
1029         pmd_t *pmd_base;
1030         pud_t *pud;
1031         void *page_addr;
1032 
1033         pud = pud_start + pud_index(addr);
1034         for (; addr < end; addr = next, pud++) {
1035                 next = pud_addr_end(addr, end);
1036 
1037                 if (!pud_present(*pud))
1038                         continue;
1039 
1040                 if (pud_large(*pud)) {
1041                         if (IS_ALIGNED(addr, PUD_SIZE) &&
1042                             IS_ALIGNED(next, PUD_SIZE)) {
1043                                 if (!direct)
1044                                         free_pagetable(pud_page(*pud),
1045                                                        get_order(PUD_SIZE));
1046 
1047                                 spin_lock(&init_mm.page_table_lock);
1048                                 pud_clear(pud);
1049                                 spin_unlock(&init_mm.page_table_lock);
1050                                 pages++;
1051                         } else {
1052                                 /* If here, we are freeing vmemmap pages. */
1053                                 memset((void *)addr, PAGE_INUSE, next - addr);
1054 
1055                                 page_addr = page_address(pud_page(*pud));
1056                                 if (!memchr_inv(page_addr, PAGE_INUSE,
1057                                                 PUD_SIZE)) {
1058                                         free_pagetable(pud_page(*pud),
1059                                                        get_order(PUD_SIZE));
1060 
1061                                         spin_lock(&init_mm.page_table_lock);
1062                                         pud_clear(pud);
1063                                         spin_unlock(&init_mm.page_table_lock);
1064                                 }
1065                         }
1066 
1067                         continue;
1068                 }
1069 
1070                 pmd_base = pmd_offset(pud, 0);
1071                 remove_pmd_table(pmd_base, addr, next, direct, altmap);
1072                 free_pmd_table(pmd_base, pud);
1073         }
1074 
1075         if (direct)
1076                 update_page_count(PG_LEVEL_1G, -pages);
1077 }
1078 
1079 static void __meminit
1080 remove_p4d_table(p4d_t *p4d_start, unsigned long addr, unsigned long end,
1081                  struct vmem_altmap *altmap, bool direct)
1082 {
1083         unsigned long next, pages = 0;
1084         pud_t *pud_base;
1085         p4d_t *p4d;
1086 
1087         p4d = p4d_start + p4d_index(addr);
1088         for (; addr < end; addr = next, p4d++) {
1089                 next = p4d_addr_end(addr, end);
1090 
1091                 if (!p4d_present(*p4d))
1092                         continue;
1093 
1094                 BUILD_BUG_ON(p4d_large(*p4d));
1095 
1096                 pud_base = pud_offset(p4d, 0);
1097                 remove_pud_table(pud_base, addr, next, altmap, direct);
1098                 /*
1099                  * For 4-level page tables we do not want to free PUDs, but in the
1100                  * 5-level case we should free them. This code will have to change
1101                  * to adapt for boot-time switching between 4 and 5 level page tables.
1102                  */
1103                 if (pgtable_l5_enabled())
1104                         free_pud_table(pud_base, p4d);
1105         }
1106 
1107         if (direct)
1108                 update_page_count(PG_LEVEL_512G, -pages);
1109 }
1110 
1111 /* start and end are both virtual address. */
1112 static void __meminit
1113 remove_pagetable(unsigned long start, unsigned long end, bool direct,
1114                 struct vmem_altmap *altmap)
1115 {
1116         unsigned long next;
1117         unsigned long addr;
1118         pgd_t *pgd;
1119         p4d_t *p4d;
1120 
1121         for (addr = start; addr < end; addr = next) {
1122                 next = pgd_addr_end(addr, end);
1123 
1124                 pgd = pgd_offset_k(addr);
1125                 if (!pgd_present(*pgd))
1126                         continue;
1127 
1128                 p4d = p4d_offset(pgd, 0);
1129                 remove_p4d_table(p4d, addr, next, altmap, direct);
1130         }
1131 
1132         flush_tlb_all();
1133 }
1134 
1135 void __ref vmemmap_free(unsigned long start, unsigned long end,
1136                 struct vmem_altmap *altmap)
1137 {
1138         remove_pagetable(start, end, false, altmap);
1139 }
1140 
1141 #ifdef CONFIG_MEMORY_HOTREMOVE
1142 static void __meminit
1143 kernel_physical_mapping_remove(unsigned long start, unsigned long end)
1144 {
1145         start = (unsigned long)__va(start);
1146         end = (unsigned long)__va(end);
1147 
1148         remove_pagetable(start, end, true, NULL);
1149 }
1150 
1151 int __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
1152 {
1153         unsigned long start_pfn = start >> PAGE_SHIFT;
1154         unsigned long nr_pages = size >> PAGE_SHIFT;
1155         struct page *page = pfn_to_page(start_pfn);
1156         struct zone *zone;
1157         int ret;
1158 
1159         /* With altmap the first mapped page is offset from @start */
1160         if (altmap)
1161                 page += vmem_altmap_offset(altmap);
1162         zone = page_zone(page);
1163         ret = __remove_pages(zone, start_pfn, nr_pages, altmap);
1164         WARN_ON_ONCE(ret);
1165         kernel_physical_mapping_remove(start, start + size);
1166 
1167         return ret;
1168 }
1169 #endif
1170 #endif /* CONFIG_MEMORY_HOTPLUG */
1171 
1172 static struct kcore_list kcore_vsyscall;
1173 
1174 static void __init register_page_bootmem_info(void)
1175 {
1176 #ifdef CONFIG_NUMA
1177         int i;
1178 
1179         for_each_online_node(i)
1180                 register_page_bootmem_info_node(NODE_DATA(i));
1181 #endif
1182 }
1183 
1184 void __init mem_init(void)
1185 {
1186         pci_iommu_alloc();
1187 
1188         /* clear_bss() already clear the empty_zero_page */
1189 
1190         /* this will put all memory onto the freelists */
1191         free_all_bootmem();
1192         after_bootmem = 1;
1193         x86_init.hyper.init_after_bootmem();
1194 
1195         /*
1196          * Must be done after boot memory is put on freelist, because here we
1197          * might set fields in deferred struct pages that have not yet been
1198          * initialized, and free_all_bootmem() initializes all the reserved
1199          * deferred pages for us.
1200          */
1201         register_page_bootmem_info();
1202 
1203         /* Register memory areas for /proc/kcore */
1204         if (get_gate_vma(&init_mm))
1205                 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR, PAGE_SIZE, KCORE_USER);
1206 
1207         mem_init_print_info(NULL);
1208 }
1209 
1210 int kernel_set_to_readonly;
1211 
1212 void set_kernel_text_rw(void)
1213 {
1214         unsigned long start = PFN_ALIGN(_text);
1215         unsigned long end = PFN_ALIGN(__stop___ex_table);
1216 
1217         if (!kernel_set_to_readonly)
1218                 return;
1219 
1220         pr_debug("Set kernel text: %lx - %lx for read write\n",
1221                  start, end);
1222 
1223         /*
1224          * Make the kernel identity mapping for text RW. Kernel text
1225          * mapping will always be RO. Refer to the comment in
1226          * static_protections() in pageattr.c
1227          */
1228         set_memory_rw(start, (end - start) >> PAGE_SHIFT);
1229 }
1230 
1231 void set_kernel_text_ro(void)
1232 {
1233         unsigned long start = PFN_ALIGN(_text);
1234         unsigned long end = PFN_ALIGN(__stop___ex_table);
1235 
1236         if (!kernel_set_to_readonly)
1237                 return;
1238 
1239         pr_debug("Set kernel text: %lx - %lx for read only\n",
1240                  start, end);
1241 
1242         /*
1243          * Set the kernel identity mapping for text RO.
1244          */
1245         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1246 }
1247 
1248 void mark_rodata_ro(void)
1249 {
1250         unsigned long start = PFN_ALIGN(_text);
1251         unsigned long rodata_start = PFN_ALIGN(__start_rodata);
1252         unsigned long end = (unsigned long) &__end_rodata_hpage_align;
1253         unsigned long text_end = PFN_ALIGN(&__stop___ex_table);
1254         unsigned long rodata_end = PFN_ALIGN(&__end_rodata);
1255         unsigned long all_end;
1256 
1257         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
1258                (end - start) >> 10);
1259         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1260 
1261         kernel_set_to_readonly = 1;
1262 
1263         /*
1264          * The rodata/data/bss/brk section (but not the kernel text!)
1265          * should also be not-executable.
1266          *
1267          * We align all_end to PMD_SIZE because the existing mapping
1268          * is a full PMD. If we would align _brk_end to PAGE_SIZE we
1269          * split the PMD and the reminder between _brk_end and the end
1270          * of the PMD will remain mapped executable.
1271          *
1272          * Any PMD which was setup after the one which covers _brk_end
1273          * has been zapped already via cleanup_highmem().
1274          */
1275         all_end = roundup((unsigned long)_brk_end, PMD_SIZE);
1276         set_memory_nx(text_end, (all_end - text_end) >> PAGE_SHIFT);
1277 
1278 #ifdef CONFIG_CPA_DEBUG
1279         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
1280         set_memory_rw(start, (end-start) >> PAGE_SHIFT);
1281 
1282         printk(KERN_INFO "Testing CPA: again\n");
1283         set_memory_ro(start, (end-start) >> PAGE_SHIFT);
1284 #endif
1285 
1286         free_kernel_image_pages((void *)text_end, (void *)rodata_start);
1287         free_kernel_image_pages((void *)rodata_end, (void *)_sdata);
1288 
1289         debug_checkwx();
1290 
1291         /*
1292          * Do this after all of the manipulation of the
1293          * kernel text page tables are complete.
1294          */
1295         pti_clone_kernel_text();
1296 }
1297 
1298 int kern_addr_valid(unsigned long addr)
1299 {
1300         unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
1301         pgd_t *pgd;
1302         p4d_t *p4d;
1303         pud_t *pud;
1304         pmd_t *pmd;
1305         pte_t *pte;
1306 
1307         if (above != 0 && above != -1UL)
1308                 return 0;
1309 
1310         pgd = pgd_offset_k(addr);
1311         if (pgd_none(*pgd))
1312                 return 0;
1313 
1314         p4d = p4d_offset(pgd, addr);
1315         if (p4d_none(*p4d))
1316                 return 0;
1317 
1318         pud = pud_offset(p4d, addr);
1319         if (pud_none(*pud))
1320                 return 0;
1321 
1322         if (pud_large(*pud))
1323                 return pfn_valid(pud_pfn(*pud));
1324 
1325         pmd = pmd_offset(pud, addr);
1326         if (pmd_none(*pmd))
1327                 return 0;
1328 
1329         if (pmd_large(*pmd))
1330                 return pfn_valid(pmd_pfn(*pmd));
1331 
1332         pte = pte_offset_kernel(pmd, addr);
1333         if (pte_none(*pte))
1334                 return 0;
1335 
1336         return pfn_valid(pte_pfn(*pte));
1337 }
1338 
1339 /*
1340  * Block size is the minimum amount of memory which can be hotplugged or
1341  * hotremoved. It must be power of two and must be equal or larger than
1342  * MIN_MEMORY_BLOCK_SIZE.
1343  */
1344 #define MAX_BLOCK_SIZE (2UL << 30)
1345 
1346 /* Amount of ram needed to start using large blocks */
1347 #define MEM_SIZE_FOR_LARGE_BLOCK (64UL << 30)
1348 
1349 /* Adjustable memory block size */
1350 static unsigned long set_memory_block_size;
1351 int __init set_memory_block_size_order(unsigned int order)
1352 {
1353         unsigned long size = 1UL << order;
1354 
1355         if (size > MEM_SIZE_FOR_LARGE_BLOCK || size < MIN_MEMORY_BLOCK_SIZE)
1356                 return -EINVAL;
1357 
1358         set_memory_block_size = size;
1359         return 0;
1360 }
1361 
1362 static unsigned long probe_memory_block_size(void)
1363 {
1364         unsigned long boot_mem_end = max_pfn << PAGE_SHIFT;
1365         unsigned long bz;
1366 
1367         /* If memory block size has been set, then use it */
1368         bz = set_memory_block_size;
1369         if (bz)
1370                 goto done;
1371 
1372         /* Use regular block if RAM is smaller than MEM_SIZE_FOR_LARGE_BLOCK */
1373         if (boot_mem_end < MEM_SIZE_FOR_LARGE_BLOCK) {
1374                 bz = MIN_MEMORY_BLOCK_SIZE;
1375                 goto done;
1376         }
1377 
1378         /* Find the largest allowed block size that aligns to memory end */
1379         for (bz = MAX_BLOCK_SIZE; bz > MIN_MEMORY_BLOCK_SIZE; bz >>= 1) {
1380                 if (IS_ALIGNED(boot_mem_end, bz))
1381                         break;
1382         }
1383 done:
1384         pr_info("x86/mm: Memory block size: %ldMB\n", bz >> 20);
1385 
1386         return bz;
1387 }
1388 
1389 static unsigned long memory_block_size_probed;
1390 unsigned long memory_block_size_bytes(void)
1391 {
1392         if (!memory_block_size_probed)
1393                 memory_block_size_probed = probe_memory_block_size();
1394 
1395         return memory_block_size_probed;
1396 }
1397 
1398 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1399 /*
1400  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1401  */
1402 static long __meminitdata addr_start, addr_end;
1403 static void __meminitdata *p_start, *p_end;
1404 static int __meminitdata node_start;
1405 
1406 static int __meminit vmemmap_populate_hugepages(unsigned long start,
1407                 unsigned long end, int node, struct vmem_altmap *altmap)
1408 {
1409         unsigned long addr;
1410         unsigned long next;
1411         pgd_t *pgd;
1412         p4d_t *p4d;
1413         pud_t *pud;
1414         pmd_t *pmd;
1415 
1416         for (addr = start; addr < end; addr = next) {
1417                 next = pmd_addr_end(addr, end);
1418 
1419                 pgd = vmemmap_pgd_populate(addr, node);
1420                 if (!pgd)
1421                         return -ENOMEM;
1422 
1423                 p4d = vmemmap_p4d_populate(pgd, addr, node);
1424                 if (!p4d)
1425                         return -ENOMEM;
1426 
1427                 pud = vmemmap_pud_populate(p4d, addr, node);
1428                 if (!pud)
1429                         return -ENOMEM;
1430 
1431                 pmd = pmd_offset(pud, addr);
1432                 if (pmd_none(*pmd)) {
1433                         void *p;
1434 
1435                         if (altmap)
1436                                 p = altmap_alloc_block_buf(PMD_SIZE, altmap);
1437                         else
1438                                 p = vmemmap_alloc_block_buf(PMD_SIZE, node);
1439                         if (p) {
1440                                 pte_t entry;
1441 
1442                                 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1443                                                 PAGE_KERNEL_LARGE);
1444                                 set_pmd(pmd, __pmd(pte_val(entry)));
1445 
1446                                 /* check to see if we have contiguous blocks */
1447                                 if (p_end != p || node_start != node) {
1448                                         if (p_start)
1449                                                 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1450                                                        addr_start, addr_end-1, p_start, p_end-1, node_start);
1451                                         addr_start = addr;
1452                                         node_start = node;
1453                                         p_start = p;
1454                                 }
1455 
1456                                 addr_end = addr + PMD_SIZE;
1457                                 p_end = p + PMD_SIZE;
1458                                 continue;
1459                         } else if (altmap)
1460                                 return -ENOMEM; /* no fallback */
1461                 } else if (pmd_large(*pmd)) {
1462                         vmemmap_verify((pte_t *)pmd, node, addr, next);
1463                         continue;
1464                 }
1465                 if (vmemmap_populate_basepages(addr, next, node))
1466                         return -ENOMEM;
1467         }
1468         return 0;
1469 }
1470 
1471 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
1472                 struct vmem_altmap *altmap)
1473 {
1474         int err;
1475 
1476         if (boot_cpu_has(X86_FEATURE_PSE))
1477                 err = vmemmap_populate_hugepages(start, end, node, altmap);
1478         else if (altmap) {
1479                 pr_err_once("%s: no cpu support for altmap allocations\n",
1480                                 __func__);
1481                 err = -ENOMEM;
1482         } else
1483                 err = vmemmap_populate_basepages(start, end, node);
1484         if (!err)
1485                 sync_global_pgds(start, end - 1);
1486         return err;
1487 }
1488 
1489 #if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HAVE_BOOTMEM_INFO_NODE)
1490 void register_page_bootmem_memmap(unsigned long section_nr,
1491                                   struct page *start_page, unsigned long nr_pages)
1492 {
1493         unsigned long addr = (unsigned long)start_page;
1494         unsigned long end = (unsigned long)(start_page + nr_pages);
1495         unsigned long next;
1496         pgd_t *pgd;
1497         p4d_t *p4d;
1498         pud_t *pud;
1499         pmd_t *pmd;
1500         unsigned int nr_pmd_pages;
1501         struct page *page;
1502 
1503         for (; addr < end; addr = next) {
1504                 pte_t *pte = NULL;
1505 
1506                 pgd = pgd_offset_k(addr);
1507                 if (pgd_none(*pgd)) {
1508                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1509                         continue;
1510                 }
1511                 get_page_bootmem(section_nr, pgd_page(*pgd), MIX_SECTION_INFO);
1512 
1513                 p4d = p4d_offset(pgd, addr);
1514                 if (p4d_none(*p4d)) {
1515                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1516                         continue;
1517                 }
1518                 get_page_bootmem(section_nr, p4d_page(*p4d), MIX_SECTION_INFO);
1519 
1520                 pud = pud_offset(p4d, addr);
1521                 if (pud_none(*pud)) {
1522                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1523                         continue;
1524                 }
1525                 get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO);
1526 
1527                 if (!boot_cpu_has(X86_FEATURE_PSE)) {
1528                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1529                         pmd = pmd_offset(pud, addr);
1530                         if (pmd_none(*pmd))
1531                                 continue;
1532                         get_page_bootmem(section_nr, pmd_page(*pmd),
1533                                          MIX_SECTION_INFO);
1534 
1535                         pte = pte_offset_kernel(pmd, addr);
1536                         if (pte_none(*pte))
1537                                 continue;
1538                         get_page_bootmem(section_nr, pte_page(*pte),
1539                                          SECTION_INFO);
1540                 } else {
1541                         next = pmd_addr_end(addr, end);
1542 
1543                         pmd = pmd_offset(pud, addr);
1544                         if (pmd_none(*pmd))
1545                                 continue;
1546 
1547                         nr_pmd_pages = 1 << get_order(PMD_SIZE);
1548                         page = pmd_page(*pmd);
1549                         while (nr_pmd_pages--)
1550                                 get_page_bootmem(section_nr, page++,
1551                                                  SECTION_INFO);
1552                 }
1553         }
1554 }
1555 #endif
1556 
1557 void __meminit vmemmap_populate_print_last(void)
1558 {
1559         if (p_start) {
1560                 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1561                         addr_start, addr_end-1, p_start, p_end-1, node_start);
1562                 p_start = NULL;
1563                 p_end = NULL;
1564                 node_start = 0;
1565         }
1566 }
1567 #endif
1568 

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