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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 <[email protected]>
6  *  Copyright (C) 2002,2003 Andi Kleen <[email protected]>
7  */
8
9 #include <linux/signal.h>
10 #include <linux/sched.h>
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/string.h>
14 #include <linux/types.h>
15 #include <linux/ptrace.h>
16 #include <linux/mman.h>
17 #include <linux/mm.h>
18 #include <linux/swap.h>
19 #include <linux/smp.h>
20 #include <linux/init.h>
21 #include <linux/initrd.h>
22 #include <linux/pagemap.h>
23 #include <linux/bootmem.h>
24 #include <linux/memblock.h>
25 #include <linux/proc_fs.h>
26 #include <linux/pci.h>
27 #include <linux/pfn.h>
28 #include <linux/poison.h>
29 #include <linux/dma-mapping.h>
30 #include <linux/module.h>
31 #include <linux/memory.h>
32 #include <linux/memory_hotplug.h>
33 #include <linux/memremap.h>
34 #include <linux/nmi.h>
35 #include <linux/gfp.h>
36 #include <linux/kcore.h>
37
38 #include <asm/processor.h>
39 #include <asm/bios_ebda.h>
40 #include <asm/uaccess.h>
41 #include <asm/pgtable.h>
42 #include <asm/pgalloc.h>
43 #include <asm/dma.h>
44 #include <asm/fixmap.h>
45 #include <asm/e820.h>
46 #include <asm/apic.h>
47 #include <asm/tlb.h>
48 #include <asm/mmu_context.h>
49 #include <asm/proto.h>
50 #include <asm/smp.h>
51 #include <asm/sections.h>
52 #include <asm/kdebug.h>
53 #include <asm/numa.h>
54 #include <asm/cacheflush.h>
55 #include <asm/init.h>
56 #include <asm/uv/uv.h>
57 #include <asm/setup.h>
58
59 #include "mm_internal.h"
60
61 #include "ident_map.c"
62
63 /*
64  * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
65  * physical space so we can cache the place of the first one and move
66  * around without checking the pgd every time.
67  */
68
69 pteval_t __supported_pte_mask __read_mostly = ~0;
70 EXPORT_SYMBOL_GPL(__supported_pte_mask);
71
72 int force_personality32;
73
74 /*
75  * noexec32=on|off
76  * Control non executable heap for 32bit processes.
77  * To control the stack too use noexec=off
78  *
79  * on   PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
80  * off  PROT_READ implies PROT_EXEC
81  */
82 static int __init nonx32_setup(char *str)
83 {
84         if (!strcmp(str, "on"))
85                 force_personality32 &= ~READ_IMPLIES_EXEC;
86         else if (!strcmp(str, "off"))
87                 force_personality32 |= READ_IMPLIES_EXEC;
88         return 1;
89 }
90 __setup("noexec32=", nonx32_setup);
91
92 /*
93  * When memory was added/removed make sure all the processes MM have
94  * suitable PGD entries in the local PGD level page.
95  */
96 void sync_global_pgds(unsigned long start, unsigned long end, int removed)
97 {
98         unsigned long address;
99
100         for (address = start; address <= end; address += PGDIR_SIZE) {
101                 const pgd_t *pgd_ref = pgd_offset_k(address);
102                 struct page *page;
103
104                 /*
105                  * When it is called after memory hot remove, pgd_none()
106                  * returns true. In this case (removed == 1), we must clear
107                  * the PGD entries in the local PGD level page.
108                  */
109                 if (pgd_none(*pgd_ref) && !removed)
110                         continue;
111
112                 spin_lock(&pgd_lock);
113                 list_for_each_entry(page, &pgd_list, lru) {
114                         pgd_t *pgd;
115                         spinlock_t *pgt_lock;
116
117                         pgd = (pgd_t *)page_address(page) + pgd_index(address);
118                         /* the pgt_lock only for Xen */
119                         pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
120                         spin_lock(pgt_lock);
121
122                         if (!pgd_none(*pgd_ref) && !pgd_none(*pgd))
123                                 BUG_ON(pgd_page_vaddr(*pgd)
124                                        != pgd_page_vaddr(*pgd_ref));
125
126                         if (removed) {
127                                 if (pgd_none(*pgd_ref) && !pgd_none(*pgd))
128                                         pgd_clear(pgd);
129                         } else {
130                                 if (pgd_none(*pgd))
131                                         set_pgd(pgd, *pgd_ref);
132                         }
133
134                         spin_unlock(pgt_lock);
135                 }
136                 spin_unlock(&pgd_lock);
137         }
138 }
139
140 /*
141  * NOTE: This function is marked __ref because it calls __init function
142  * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
143  */
144 static __ref void *spp_getpage(void)
145 {
146         void *ptr;
147
148         if (after_bootmem)
149                 ptr = (void *) get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK);
150         else
151                 ptr = alloc_bootmem_pages(PAGE_SIZE);
152
153         if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
154                 panic("set_pte_phys: cannot allocate page data %s\n",
155                         after_bootmem ? "after bootmem" : "");
156         }
157
158         pr_debug("spp_getpage %p\n", ptr);
159
160         return ptr;
161 }
162
163 static pud_t *fill_pud(pgd_t *pgd, unsigned long vaddr)
164 {
165         if (pgd_none(*pgd)) {
166                 pud_t *pud = (pud_t *)spp_getpage();
167                 pgd_populate(&init_mm, pgd, pud);
168                 if (pud != pud_offset(pgd, 0))
169                         printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n",
170                                pud, pud_offset(pgd, 0));
171         }
172         return pud_offset(pgd, vaddr);
173 }
174
175 static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr)
176 {
177         if (pud_none(*pud)) {
178                 pmd_t *pmd = (pmd_t *) spp_getpage();
179                 pud_populate(&init_mm, pud, pmd);
180                 if (pmd != pmd_offset(pud, 0))
181                         printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
182                                pmd, pmd_offset(pud, 0));
183         }
184         return pmd_offset(pud, vaddr);
185 }
186
187 static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr)
188 {
189         if (pmd_none(*pmd)) {
190                 pte_t *pte = (pte_t *) spp_getpage();
191                 pmd_populate_kernel(&init_mm, pmd, pte);
192                 if (pte != pte_offset_kernel(pmd, 0))
193                         printk(KERN_ERR "PAGETABLE BUG #02!\n");
194         }
195         return pte_offset_kernel(pmd, vaddr);
196 }
197
198 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
199 {
200         pud_t *pud;
201         pmd_t *pmd;
202         pte_t *pte;
203
204         pud = pud_page + pud_index(vaddr);
205         pmd = fill_pmd(pud, vaddr);
206         pte = fill_pte(pmd, vaddr);
207
208         set_pte(pte, new_pte);
209
210         /*
211          * It's enough to flush this one mapping.
212          * (PGE mappings get flushed as well)
213          */
214         __flush_tlb_one(vaddr);
215 }
216
217 void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
218 {
219         pgd_t *pgd;
220         pud_t *pud_page;
221
222         pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
223
224         pgd = pgd_offset_k(vaddr);
225         if (pgd_none(*pgd)) {
226                 printk(KERN_ERR
227                         "PGD FIXMAP MISSING, it should be setup in head.S!\n");
228                 return;
229         }
230         pud_page = (pud_t*)pgd_page_vaddr(*pgd);
231         set_pte_vaddr_pud(pud_page, vaddr, pteval);
232 }
233
234 pmd_t * __init populate_extra_pmd(unsigned long vaddr)
235 {
236         pgd_t *pgd;
237         pud_t *pud;
238
239         pgd = pgd_offset_k(vaddr);
240         pud = fill_pud(pgd, vaddr);
241         return fill_pmd(pud, vaddr);
242 }
243
244 pte_t * __init populate_extra_pte(unsigned long vaddr)
245 {
246         pmd_t *pmd;
247
248         pmd = populate_extra_pmd(vaddr);
249         return fill_pte(pmd, vaddr);
250 }
251
252 /*
253  * Create large page table mappings for a range of physical addresses.
254  */
255 static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
256                                         enum page_cache_mode cache)
257 {
258         pgd_t *pgd;
259         pud_t *pud;
260         pmd_t *pmd;
261         pgprot_t prot;
262
263         pgprot_val(prot) = pgprot_val(PAGE_KERNEL_LARGE) |
264                 pgprot_val(pgprot_4k_2_large(cachemode2pgprot(cache)));
265         BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
266         for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
267                 pgd = pgd_offset_k((unsigned long)__va(phys));
268                 if (pgd_none(*pgd)) {
269                         pud = (pud_t *) spp_getpage();
270                         set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE |
271                                                 _PAGE_USER));
272                 }
273                 pud = pud_offset(pgd, (unsigned long)__va(phys));
274                 if (pud_none(*pud)) {
275                         pmd = (pmd_t *) spp_getpage();
276                         set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
277                                                 _PAGE_USER));
278                 }
279                 pmd = pmd_offset(pud, phys);
280                 BUG_ON(!pmd_none(*pmd));
281                 set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
282         }
283 }
284
285 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
286 {
287         __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_WB);
288 }
289
290 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
291 {
292         __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_UC);
293 }
294
295 /*
296  * The head.S code sets up the kernel high mapping:
297  *
298  *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
299  *
300  * phys_base holds the negative offset to the kernel, which is added
301  * to the compile time generated pmds. This results in invalid pmds up
302  * to the point where we hit the physaddr 0 mapping.
303  *
304  * We limit the mappings to the region from _text to _brk_end.  _brk_end
305  * is rounded up to the 2MB boundary. This catches the invalid pmds as
306  * well, as they are located before _text:
307  */
308 void __init cleanup_highmap(void)
309 {
310         unsigned long vaddr = __START_KERNEL_map;
311         unsigned long vaddr_end = __START_KERNEL_map + KERNEL_IMAGE_SIZE;
312         unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1;
313         pmd_t *pmd = level2_kernel_pgt;
314
315         /*
316          * Native path, max_pfn_mapped is not set yet.
317          * Xen has valid max_pfn_mapped set in
318          *      arch/x86/xen/mmu.c:xen_setup_kernel_pagetable().
319          */
320         if (max_pfn_mapped)
321                 vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT);
322
323         for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) {
324                 if (pmd_none(*pmd))
325                         continue;
326                 if (vaddr < (unsigned long) _text || vaddr > end)
327                         set_pmd(pmd, __pmd(0));
328         }
329 }
330
331 /*
332  * Create PTE level page table mapping for physical addresses.
333  * It returns the last physical address mapped.
334  */
335 static unsigned long __meminit
336 phys_pte_init(pte_t *pte_page, unsigned long paddr, unsigned long paddr_end,
337               pgprot_t prot)
338 {
339         unsigned long pages = 0, paddr_next;
340         unsigned long paddr_last = paddr_end;
341         pte_t *pte;
342         int i;
343
344         pte = pte_page + pte_index(paddr);
345         i = pte_index(paddr);
346
347         for (; i < PTRS_PER_PTE; i++, paddr = paddr_next, pte++) {
348                 paddr_next = (paddr & PAGE_MASK) + PAGE_SIZE;
349                 if (paddr >= paddr_end) {
350                         if (!after_bootmem &&
351                             !e820_any_mapped(paddr & PAGE_MASK, paddr_next,
352                                              E820_RAM) &&
353                             !e820_any_mapped(paddr & PAGE_MASK, paddr_next,
354                                              E820_RESERVED_KERN))
355                                 set_pte(pte, __pte(0));
356                         continue;
357                 }
358
359                 /*
360                  * We will re-use the existing mapping.
361                  * Xen for example has some special requirements, like mapping
362                  * pagetable pages as RO. So assume someone who pre-setup
363                  * these mappings are more intelligent.
364                  */
365                 if (pte_val(*pte)) {
366                         if (!after_bootmem)
367                                 pages++;
368                         continue;
369                 }
370
371                 if (0)
372                         pr_info("   pte=%p addr=%lx pte=%016lx\n", pte, paddr,
373                                 pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL).pte);
374                 pages++;
375                 set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, prot));
376                 paddr_last = (paddr & PAGE_MASK) + PAGE_SIZE;
377         }
378
379         update_page_count(PG_LEVEL_4K, pages);
380
381         return paddr_last;
382 }
383
384 /*
385  * Create PMD level page table mapping for physical addresses. The virtual
386  * and physical address have to be aligned at this level.
387  * It returns the last physical address mapped.
388  */
389 static unsigned long __meminit
390 phys_pmd_init(pmd_t *pmd_page, unsigned long paddr, unsigned long paddr_end,
391               unsigned long page_size_mask, pgprot_t prot)
392 {
393         unsigned long pages = 0, paddr_next;
394         unsigned long paddr_last = paddr_end;
395
396         int i = pmd_index(paddr);
397
398         for (; i < PTRS_PER_PMD; i++, paddr = paddr_next) {
399                 pmd_t *pmd = pmd_page + pmd_index(paddr);
400                 pte_t *pte;
401                 pgprot_t new_prot = prot;
402
403                 paddr_next = (paddr & PMD_MASK) + PMD_SIZE;
404                 if (paddr >= paddr_end) {
405                         if (!after_bootmem &&
406                             !e820_any_mapped(paddr & PMD_MASK, paddr_next,
407                                              E820_RAM) &&
408                             !e820_any_mapped(paddr & PMD_MASK, paddr_next,
409                                              E820_RESERVED_KERN))
410                                 set_pmd(pmd, __pmd(0));
411                         continue;
412                 }
413
414                 if (pmd_val(*pmd)) {
415                         if (!pmd_large(*pmd)) {
416                                 spin_lock(&init_mm.page_table_lock);
417                                 pte = (pte_t *)pmd_page_vaddr(*pmd);
418                                 paddr_last = phys_pte_init(pte, paddr,
419                                                            paddr_end, prot);
420                                 spin_unlock(&init_mm.page_table_lock);
421                                 continue;
422                         }
423                         /*
424                          * If we are ok with PG_LEVEL_2M mapping, then we will
425                          * use the existing mapping,
426                          *
427                          * Otherwise, we will split the large page mapping but
428                          * use the same existing protection bits except for
429                          * large page, so that we don't violate Intel's TLB
430                          * Application note (317080) which says, while changing
431                          * the page sizes, new and old translations should
432                          * not differ with respect to page frame and
433                          * attributes.
434                          */
435                         if (page_size_mask & (1 << PG_LEVEL_2M)) {
436                                 if (!after_bootmem)
437                                         pages++;
438                                 paddr_last = paddr_next;
439                                 continue;
440                         }
441                         new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
442                 }
443
444                 if (page_size_mask & (1<<PG_LEVEL_2M)) {
445                         pages++;
446                         spin_lock(&init_mm.page_table_lock);
447                         set_pte((pte_t *)pmd,
448                                 pfn_pte((paddr & PMD_MASK) >> PAGE_SHIFT,
449                                         __pgprot(pgprot_val(prot) | _PAGE_PSE)));
450                         spin_unlock(&init_mm.page_table_lock);
451                         paddr_last = paddr_next;
452                         continue;
453                 }
454
455                 pte = alloc_low_page();
456                 paddr_last = phys_pte_init(pte, paddr, paddr_end, new_prot);
457
458                 spin_lock(&init_mm.page_table_lock);
459                 pmd_populate_kernel(&init_mm, pmd, pte);
460                 spin_unlock(&init_mm.page_table_lock);
461         }
462         update_page_count(PG_LEVEL_2M, pages);
463         return paddr_last;
464 }
465
466 /*
467  * Create PUD level page table mapping for physical addresses. The virtual
468  * and physical address do not have to be aligned at this level. KASLR can
469  * randomize virtual addresses up to this level.
470  * It returns the last physical address mapped.
471  */
472 static unsigned long __meminit
473 phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end,
474               unsigned long page_size_mask)
475 {
476         unsigned long pages = 0, paddr_next;
477         unsigned long paddr_last = paddr_end;
478         unsigned long vaddr = (unsigned long)__va(paddr);
479         int i = pud_index(vaddr);
480
481         for (; i < PTRS_PER_PUD; i++, paddr = paddr_next) {
482                 pud_t *pud;
483                 pmd_t *pmd;
484                 pgprot_t prot = PAGE_KERNEL;
485
486                 vaddr = (unsigned long)__va(paddr);
487                 pud = pud_page + pud_index(vaddr);
488                 paddr_next = (paddr & PUD_MASK) + PUD_SIZE;
489
490                 if (paddr >= paddr_end) {
491                         if (!after_bootmem &&
492                             !e820_any_mapped(paddr & PUD_MASK, paddr_next,
493                                              E820_RAM) &&
494                             !e820_any_mapped(paddr & PUD_MASK, paddr_next,
495                                              E820_RESERVED_KERN))
496                                 set_pud(pud, __pud(0));
497                         continue;
498                 }
499
500                 if (pud_val(*pud)) {
501                         if (!pud_large(*pud)) {
502                                 pmd = pmd_offset(pud, 0);
503                                 paddr_last = phys_pmd_init(pmd, paddr,
504                                                            paddr_end,
505                                                            page_size_mask,
506                                                            prot);
507                                 __flush_tlb_all();
508                                 continue;
509                         }
510                         /*
511                          * If we are ok with PG_LEVEL_1G mapping, then we will
512                          * use the existing mapping.
513                          *
514                          * Otherwise, we will split the gbpage mapping but use
515                          * the same existing protection  bits except for large
516                          * page, so that we don't violate Intel's TLB
517                          * Application note (317080) which says, while changing
518                          * the page sizes, new and old translations should
519                          * not differ with respect to page frame and
520                          * attributes.
521                          */
522                         if (page_size_mask & (1 << PG_LEVEL_1G)) {
523                                 if (!after_bootmem)
524                                         pages++;
525                                 paddr_last = paddr_next;
526                                 continue;
527                         }
528                         prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
529                 }
530
531                 if (page_size_mask & (1<<PG_LEVEL_1G)) {
532                         pages++;
533                         spin_lock(&init_mm.page_table_lock);
534                         set_pte((pte_t *)pud,
535                                 pfn_pte((paddr & PUD_MASK) >> PAGE_SHIFT,
536                                         PAGE_KERNEL_LARGE));
537                         spin_unlock(&init_mm.page_table_lock);
538                         paddr_last = paddr_next;
539                         continue;
540                 }
541
542                 pmd = alloc_low_page();
543                 paddr_last = phys_pmd_init(pmd, paddr, paddr_end,
544                                            page_size_mask, prot);
545
546                 spin_lock(&init_mm.page_table_lock);
547                 pud_populate(&init_mm, pud, pmd);
548                 spin_unlock(&init_mm.page_table_lock);
549         }
550         __flush_tlb_all();
551
552         update_page_count(PG_LEVEL_1G, pages);
553
554         return paddr_last;
555 }
556
557 /*
558  * Create page table mapping for the physical memory for specific physical
559  * addresses. The virtual and physical addresses have to be aligned on PMD level
560  * down. It returns the last physical address mapped.
561  */
562 unsigned long __meminit
563 kernel_physical_mapping_init(unsigned long paddr_start,
564                              unsigned long paddr_end,
565                              unsigned long page_size_mask)
566 {
567         bool pgd_changed = false;
568         unsigned long vaddr, vaddr_start, vaddr_end, vaddr_next, paddr_last;
569
570         paddr_last = paddr_end;
571         vaddr = (unsigned long)__va(paddr_start);
572         vaddr_end = (unsigned long)__va(paddr_end);
573         vaddr_start = vaddr;
574
575         for (; vaddr < vaddr_end; vaddr = vaddr_next) {
576                 pgd_t *pgd = pgd_offset_k(vaddr);
577                 pud_t *pud;
578
579                 vaddr_next = (vaddr & PGDIR_MASK) + PGDIR_SIZE;
580
581                 if (pgd_val(*pgd)) {
582                         pud = (pud_t *)pgd_page_vaddr(*pgd);
583                         paddr_last = phys_pud_init(pud, __pa(vaddr),
584                                                    __pa(vaddr_end),
585                                                    page_size_mask);
586                         continue;
587                 }
588
589                 pud = alloc_low_page();
590                 paddr_last = phys_pud_init(pud, __pa(vaddr), __pa(vaddr_end),
591                                            page_size_mask);
592
593                 spin_lock(&init_mm.page_table_lock);
594                 pgd_populate(&init_mm, pgd, pud);
595                 spin_unlock(&init_mm.page_table_lock);
596                 pgd_changed = true;
597         }
598
599         if (pgd_changed)
600                 sync_global_pgds(vaddr_start, vaddr_end - 1, 0);
601
602         __flush_tlb_all();
603
604         return paddr_last;
605 }
606
607 #ifndef CONFIG_NUMA
608 void __init initmem_init(void)
609 {
610         memblock_set_node(0, (phys_addr_t)ULLONG_MAX, &memblock.memory, 0);
611 }
612 #endif
613
614 void __init paging_init(void)
615 {
616         sparse_memory_present_with_active_regions(MAX_NUMNODES);
617         sparse_init();
618
619         /*
620          * clear the default setting with node 0
621          * note: don't use nodes_clear here, that is really clearing when
622          *       numa support is not compiled in, and later node_set_state
623          *       will not set it back.
624          */
625         node_clear_state(0, N_MEMORY);
626         if (N_MEMORY != N_NORMAL_MEMORY)
627                 node_clear_state(0, N_NORMAL_MEMORY);
628
629         zone_sizes_init();
630 }
631
632 /*
633  * Memory hotplug specific functions
634  */
635 #ifdef CONFIG_MEMORY_HOTPLUG
636 /*
637  * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
638  * updating.
639  */
640 static void  update_end_of_memory_vars(u64 start, u64 size)
641 {
642         unsigned long end_pfn = PFN_UP(start + size);
643
644         if (end_pfn > max_pfn) {
645                 max_pfn = end_pfn;
646                 max_low_pfn = end_pfn;
647                 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
648         }
649 }
650
651 /*
652  * Memory is added always to NORMAL zone. This means you will never get
653  * additional DMA/DMA32 memory.
654  */
655 int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
656 {
657         struct pglist_data *pgdat = NODE_DATA(nid);
658         struct zone *zone = pgdat->node_zones +
659                 zone_for_memory(nid, start, size, ZONE_NORMAL, for_device);
660         unsigned long start_pfn = start >> PAGE_SHIFT;
661         unsigned long nr_pages = size >> PAGE_SHIFT;
662         int ret;
663
664         init_memory_mapping(start, start + size);
665
666         ret = __add_pages(nid, zone, start_pfn, nr_pages);
667         WARN_ON_ONCE(ret);
668
669         /* update max_pfn, max_low_pfn and high_memory */
670         update_end_of_memory_vars(start, size);
671
672         return ret;
673 }
674 EXPORT_SYMBOL_GPL(arch_add_memory);
675
676 #define PAGE_INUSE 0xFD
677
678 static void __meminit free_pagetable(struct page *page, int order)
679 {
680         unsigned long magic;
681         unsigned int nr_pages = 1 << order;
682         struct vmem_altmap *altmap = to_vmem_altmap((unsigned long) page);
683
684         if (altmap) {
685                 vmem_altmap_free(altmap, nr_pages);
686                 return;
687         }
688
689         /* bootmem page has reserved flag */
690         if (PageReserved(page)) {
691                 __ClearPageReserved(page);
692
693                 magic = (unsigned long)page->lru.next;
694                 if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
695                         while (nr_pages--)
696                                 put_page_bootmem(page++);
697                 } else
698                         while (nr_pages--)
699                                 free_reserved_page(page++);
700         } else
701                 free_pages((unsigned long)page_address(page), order);
702 }
703
704 static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
705 {
706         pte_t *pte;
707         int i;
708
709         for (i = 0; i < PTRS_PER_PTE; i++) {
710                 pte = pte_start + i;
711                 if (pte_val(*pte))
712                         return;
713         }
714
715         /* free a pte talbe */
716         free_pagetable(pmd_page(*pmd), 0);
717         spin_lock(&init_mm.page_table_lock);
718         pmd_clear(pmd);
719         spin_unlock(&init_mm.page_table_lock);
720 }
721
722 static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
723 {
724         pmd_t *pmd;
725         int i;
726
727         for (i = 0; i < PTRS_PER_PMD; i++) {
728                 pmd = pmd_start + i;
729                 if (pmd_val(*pmd))
730                         return;
731         }
732
733         /* free a pmd talbe */
734         free_pagetable(pud_page(*pud), 0);
735         spin_lock(&init_mm.page_table_lock);
736         pud_clear(pud);
737         spin_unlock(&init_mm.page_table_lock);
738 }
739
740 /* Return true if pgd is changed, otherwise return false. */
741 static bool __meminit free_pud_table(pud_t *pud_start, pgd_t *pgd)
742 {
743         pud_t *pud;
744         int i;
745
746         for (i = 0; i < PTRS_PER_PUD; i++) {
747                 pud = pud_start + i;
748                 if (pud_val(*pud))
749                         return false;
750         }
751
752         /* free a pud table */
753         free_pagetable(pgd_page(*pgd), 0);
754         spin_lock(&init_mm.page_table_lock);
755         pgd_clear(pgd);
756         spin_unlock(&init_mm.page_table_lock);
757
758         return true;
759 }
760
761 static void __meminit
762 remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
763                  bool direct)
764 {
765         unsigned long next, pages = 0;
766         pte_t *pte;
767         void *page_addr;
768         phys_addr_t phys_addr;
769
770         pte = pte_start + pte_index(addr);
771         for (; addr < end; addr = next, pte++) {
772                 next = (addr + PAGE_SIZE) & PAGE_MASK;
773                 if (next > end)
774                         next = end;
775
776                 if (!pte_present(*pte))
777                         continue;
778
779                 /*
780                  * We mapped [0,1G) memory as identity mapping when
781                  * initializing, in arch/x86/kernel/head_64.S. These
782                  * pagetables cannot be removed.
783                  */
784                 phys_addr = pte_val(*pte) + (addr & PAGE_MASK);
785                 if (phys_addr < (phys_addr_t)0x40000000)
786                         return;
787
788                 if (PAGE_ALIGNED(addr) && PAGE_ALIGNED(next)) {
789                         /*
790                          * Do not free direct mapping pages since they were
791                          * freed when offlining, or simplely not in use.
792                          */
793                         if (!direct)
794                                 free_pagetable(pte_page(*pte), 0);
795
796                         spin_lock(&init_mm.page_table_lock);
797                         pte_clear(&init_mm, addr, pte);
798                         spin_unlock(&init_mm.page_table_lock);
799
800                         /* For non-direct mapping, pages means nothing. */
801                         pages++;
802                 } else {
803                         /*
804                          * If we are here, we are freeing vmemmap pages since
805                          * direct mapped memory ranges to be freed are aligned.
806                          *
807                          * If we are not removing the whole page, it means
808                          * other page structs in this page are being used and
809                          * we canot remove them. So fill the unused page_structs
810                          * with 0xFD, and remove the page when it is wholly
811                          * filled with 0xFD.
812                          */
813                         memset((void *)addr, PAGE_INUSE, next - addr);
814
815                         page_addr = page_address(pte_page(*pte));
816                         if (!memchr_inv(page_addr, PAGE_INUSE, PAGE_SIZE)) {
817                                 free_pagetable(pte_page(*pte), 0);
818
819                                 spin_lock(&init_mm.page_table_lock);
820                                 pte_clear(&init_mm, addr, pte);
821                                 spin_unlock(&init_mm.page_table_lock);
822                         }
823                 }
824         }
825
826         /* Call free_pte_table() in remove_pmd_table(). */
827         flush_tlb_all();
828         if (direct)
829                 update_page_count(PG_LEVEL_4K, -pages);
830 }
831
832 static void __meminit
833 remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
834                  bool direct)
835 {
836         unsigned long next, pages = 0;
837         pte_t *pte_base;
838         pmd_t *pmd;
839         void *page_addr;
840
841         pmd = pmd_start + pmd_index(addr);
842         for (; addr < end; addr = next, pmd++) {
843                 next = pmd_addr_end(addr, end);
844
845                 if (!pmd_present(*pmd))
846                         continue;
847
848                 if (pmd_large(*pmd)) {
849                         if (IS_ALIGNED(addr, PMD_SIZE) &&
850                             IS_ALIGNED(next, PMD_SIZE)) {
851                                 if (!direct)
852                                         free_pagetable(pmd_page(*pmd),
853                                                        get_order(PMD_SIZE));
854
855                                 spin_lock(&init_mm.page_table_lock);
856                                 pmd_clear(pmd);
857                                 spin_unlock(&init_mm.page_table_lock);
858                                 pages++;
859                         } else {
860                                 /* If here, we are freeing vmemmap pages. */
861                                 memset((void *)addr, PAGE_INUSE, next - addr);
862
863                                 page_addr = page_address(pmd_page(*pmd));
864                                 if (!memchr_inv(page_addr, PAGE_INUSE,
865                                                 PMD_SIZE)) {
866                                         free_pagetable(pmd_page(*pmd),
867                                                        get_order(PMD_SIZE));
868
869                                         spin_lock(&init_mm.page_table_lock);
870                                         pmd_clear(pmd);
871                                         spin_unlock(&init_mm.page_table_lock);
872                                 }
873                         }
874
875                         continue;
876                 }
877
878                 pte_base = (pte_t *)pmd_page_vaddr(*pmd);
879                 remove_pte_table(pte_base, addr, next, direct);
880                 free_pte_table(pte_base, pmd);
881         }
882
883         /* Call free_pmd_table() in remove_pud_table(). */
884         if (direct)
885                 update_page_count(PG_LEVEL_2M, -pages);
886 }
887
888 static void __meminit
889 remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
890                  bool direct)
891 {
892         unsigned long next, pages = 0;
893         pmd_t *pmd_base;
894         pud_t *pud;
895         void *page_addr;
896
897         pud = pud_start + pud_index(addr);
898         for (; addr < end; addr = next, pud++) {
899                 next = pud_addr_end(addr, end);
900
901                 if (!pud_present(*pud))
902                         continue;
903
904                 if (pud_large(*pud)) {
905                         if (IS_ALIGNED(addr, PUD_SIZE) &&
906                             IS_ALIGNED(next, PUD_SIZE)) {
907                                 if (!direct)
908                                         free_pagetable(pud_page(*pud),
909                                                        get_order(PUD_SIZE));
910
911                                 spin_lock(&init_mm.page_table_lock);
912                                 pud_clear(pud);
913                                 spin_unlock(&init_mm.page_table_lock);
914                                 pages++;
915                         } else {
916                                 /* If here, we are freeing vmemmap pages. */
917                                 memset((void *)addr, PAGE_INUSE, next - addr);
918
919                                 page_addr = page_address(pud_page(*pud));
920                                 if (!memchr_inv(page_addr, PAGE_INUSE,
921                                                 PUD_SIZE)) {
922                                         free_pagetable(pud_page(*pud),
923                                                        get_order(PUD_SIZE));
924
925                                         spin_lock(&init_mm.page_table_lock);
926                                         pud_clear(pud);
927                                         spin_unlock(&init_mm.page_table_lock);
928                                 }
929                         }
930
931                         continue;
932                 }
933
934                 pmd_base = (pmd_t *)pud_page_vaddr(*pud);
935                 remove_pmd_table(pmd_base, addr, next, direct);
936                 free_pmd_table(pmd_base, pud);
937         }
938
939         if (direct)
940                 update_page_count(PG_LEVEL_1G, -pages);
941 }
942
943 /* start and end are both virtual address. */
944 static void __meminit
945 remove_pagetable(unsigned long start, unsigned long end, bool direct)
946 {
947         unsigned long next;
948         unsigned long addr;
949         pgd_t *pgd;
950         pud_t *pud;
951         bool pgd_changed = false;
952
953         for (addr = start; addr < end; addr = next) {
954                 next = pgd_addr_end(addr, end);
955
956                 pgd = pgd_offset_k(addr);
957                 if (!pgd_present(*pgd))
958                         continue;
959
960                 pud = (pud_t *)pgd_page_vaddr(*pgd);
961                 remove_pud_table(pud, addr, next, direct);
962                 if (free_pud_table(pud, pgd))
963                         pgd_changed = true;
964         }
965
966         if (pgd_changed)
967                 sync_global_pgds(start, end - 1, 1);
968
969         flush_tlb_all();
970 }
971
972 void __ref vmemmap_free(unsigned long start, unsigned long end)
973 {
974         remove_pagetable(start, end, false);
975 }
976
977 #ifdef CONFIG_MEMORY_HOTREMOVE
978 static void __meminit
979 kernel_physical_mapping_remove(unsigned long start, unsigned long end)
980 {
981         start = (unsigned long)__va(start);
982         end = (unsigned long)__va(end);
983
984         remove_pagetable(start, end, true);
985 }
986
987 int __ref arch_remove_memory(u64 start, u64 size)
988 {
989         unsigned long start_pfn = start >> PAGE_SHIFT;
990         unsigned long nr_pages = size >> PAGE_SHIFT;
991         struct page *page = pfn_to_page(start_pfn);
992         struct vmem_altmap *altmap;
993         struct zone *zone;
994         int ret;
995
996         /* With altmap the first mapped page is offset from @start */
997         altmap = to_vmem_altmap((unsigned long) page);
998         if (altmap)
999                 page += vmem_altmap_offset(altmap);
1000         zone = page_zone(page);
1001         ret = __remove_pages(zone, start_pfn, nr_pages);
1002         WARN_ON_ONCE(ret);
1003         kernel_physical_mapping_remove(start, start + size);
1004
1005         return ret;
1006 }
1007 #endif
1008 #endif /* CONFIG_MEMORY_HOTPLUG */
1009
1010 static struct kcore_list kcore_vsyscall;
1011
1012 static void __init register_page_bootmem_info(void)
1013 {
1014 #ifdef CONFIG_NUMA
1015         int i;
1016
1017         for_each_online_node(i)
1018                 register_page_bootmem_info_node(NODE_DATA(i));
1019 #endif
1020 }
1021
1022 void __init mem_init(void)
1023 {
1024         pci_iommu_alloc();
1025
1026         /* clear_bss() already clear the empty_zero_page */
1027
1028         register_page_bootmem_info();
1029
1030         /* this will put all memory onto the freelists */
1031         free_all_bootmem();
1032         after_bootmem = 1;
1033
1034         /* Register memory areas for /proc/kcore */
1035         kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR,
1036                          PAGE_SIZE, KCORE_OTHER);
1037
1038         mem_init_print_info(NULL);
1039 }
1040
1041 const int rodata_test_data = 0xC3;
1042 EXPORT_SYMBOL_GPL(rodata_test_data);
1043
1044 int kernel_set_to_readonly;
1045
1046 void set_kernel_text_rw(void)
1047 {
1048         unsigned long start = PFN_ALIGN(_text);
1049         unsigned long end = PFN_ALIGN(__stop___ex_table);
1050
1051         if (!kernel_set_to_readonly)
1052                 return;
1053
1054         pr_debug("Set kernel text: %lx - %lx for read write\n",
1055                  start, end);
1056
1057         /*
1058          * Make the kernel identity mapping for text RW. Kernel text
1059          * mapping will always be RO. Refer to the comment in
1060          * static_protections() in pageattr.c
1061          */
1062         set_memory_rw(start, (end - start) >> PAGE_SHIFT);
1063 }
1064
1065 void set_kernel_text_ro(void)
1066 {
1067         unsigned long start = PFN_ALIGN(_text);
1068         unsigned long end = PFN_ALIGN(__stop___ex_table);
1069
1070         if (!kernel_set_to_readonly)
1071                 return;
1072
1073         pr_debug("Set kernel text: %lx - %lx for read only\n",
1074                  start, end);
1075
1076         /*
1077          * Set the kernel identity mapping for text RO.
1078          */
1079         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1080 }
1081
1082 void mark_rodata_ro(void)
1083 {
1084         unsigned long start = PFN_ALIGN(_text);
1085         unsigned long rodata_start = PFN_ALIGN(__start_rodata);
1086         unsigned long end = (unsigned long) &__end_rodata_hpage_align;
1087         unsigned long text_end = PFN_ALIGN(&__stop___ex_table);
1088         unsigned long rodata_end = PFN_ALIGN(&__end_rodata);
1089         unsigned long all_end;
1090
1091         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
1092                (end - start) >> 10);
1093         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1094
1095         kernel_set_to_readonly = 1;
1096
1097         /*
1098          * The rodata/data/bss/brk section (but not the kernel text!)
1099          * should also be not-executable.
1100          *
1101          * We align all_end to PMD_SIZE because the existing mapping
1102          * is a full PMD. If we would align _brk_end to PAGE_SIZE we
1103          * split the PMD and the reminder between _brk_end and the end
1104          * of the PMD will remain mapped executable.
1105          *
1106          * Any PMD which was setup after the one which covers _brk_end
1107          * has been zapped already via cleanup_highmem().
1108          */
1109         all_end = roundup((unsigned long)_brk_end, PMD_SIZE);
1110         set_memory_nx(text_end, (all_end - text_end) >> PAGE_SHIFT);
1111
1112         rodata_test();
1113
1114 #ifdef CONFIG_CPA_DEBUG
1115         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
1116         set_memory_rw(start, (end-start) >> PAGE_SHIFT);
1117
1118         printk(KERN_INFO "Testing CPA: again\n");
1119         set_memory_ro(start, (end-start) >> PAGE_SHIFT);
1120 #endif
1121
1122         free_init_pages("unused kernel",
1123                         (unsigned long) __va(__pa_symbol(text_end)),
1124                         (unsigned long) __va(__pa_symbol(rodata_start)));
1125         free_init_pages("unused kernel",
1126                         (unsigned long) __va(__pa_symbol(rodata_end)),
1127                         (unsigned long) __va(__pa_symbol(_sdata)));
1128
1129         debug_checkwx();
1130 }
1131
1132 int kern_addr_valid(unsigned long addr)
1133 {
1134         unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
1135         pgd_t *pgd;
1136         pud_t *pud;
1137         pmd_t *pmd;
1138         pte_t *pte;
1139
1140         if (above != 0 && above != -1UL)
1141                 return 0;
1142
1143         pgd = pgd_offset_k(addr);
1144         if (pgd_none(*pgd))
1145                 return 0;
1146
1147         pud = pud_offset(pgd, addr);
1148         if (pud_none(*pud))
1149                 return 0;
1150
1151         if (pud_large(*pud))
1152                 return pfn_valid(pud_pfn(*pud));
1153
1154         pmd = pmd_offset(pud, addr);
1155         if (pmd_none(*pmd))
1156                 return 0;
1157
1158         if (pmd_large(*pmd))
1159                 return pfn_valid(pmd_pfn(*pmd));
1160
1161         pte = pte_offset_kernel(pmd, addr);
1162         if (pte_none(*pte))
1163                 return 0;
1164
1165         return pfn_valid(pte_pfn(*pte));
1166 }
1167
1168 static unsigned long probe_memory_block_size(void)
1169 {
1170         unsigned long bz = MIN_MEMORY_BLOCK_SIZE;
1171
1172         /* if system is UV or has 64GB of RAM or more, use large blocks */
1173         if (is_uv_system() || ((max_pfn << PAGE_SHIFT) >= (64UL << 30)))
1174                 bz = 2UL << 30; /* 2GB */
1175
1176         pr_info("x86/mm: Memory block size: %ldMB\n", bz >> 20);
1177
1178         return bz;
1179 }
1180
1181 static unsigned long memory_block_size_probed;
1182 unsigned long memory_block_size_bytes(void)
1183 {
1184         if (!memory_block_size_probed)
1185                 memory_block_size_probed = probe_memory_block_size();
1186
1187         return memory_block_size_probed;
1188 }
1189
1190 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1191 /*
1192  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1193  */
1194 static long __meminitdata addr_start, addr_end;
1195 static void __meminitdata *p_start, *p_end;
1196 static int __meminitdata node_start;
1197
1198 static int __meminit vmemmap_populate_hugepages(unsigned long start,
1199                 unsigned long end, int node, struct vmem_altmap *altmap)
1200 {
1201         unsigned long addr;
1202         unsigned long next;
1203         pgd_t *pgd;
1204         pud_t *pud;
1205         pmd_t *pmd;
1206
1207         for (addr = start; addr < end; addr = next) {
1208                 next = pmd_addr_end(addr, end);
1209
1210                 pgd = vmemmap_pgd_populate(addr, node);
1211                 if (!pgd)
1212                         return -ENOMEM;
1213
1214                 pud = vmemmap_pud_populate(pgd, addr, node);
1215                 if (!pud)
1216                         return -ENOMEM;
1217
1218                 pmd = pmd_offset(pud, addr);
1219                 if (pmd_none(*pmd)) {
1220                         void *p;
1221
1222                         p = __vmemmap_alloc_block_buf(PMD_SIZE, node, altmap);
1223                         if (p) {
1224                                 pte_t entry;
1225
1226                                 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1227                                                 PAGE_KERNEL_LARGE);
1228                                 set_pmd(pmd, __pmd(pte_val(entry)));
1229
1230                                 /* check to see if we have contiguous blocks */
1231                                 if (p_end != p || node_start != node) {
1232                                         if (p_start)
1233                                                 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1234                                                        addr_start, addr_end-1, p_start, p_end-1, node_start);
1235                                         addr_start = addr;
1236                                         node_start = node;
1237                                         p_start = p;
1238                                 }
1239
1240                                 addr_end = addr + PMD_SIZE;
1241                                 p_end = p + PMD_SIZE;
1242                                 continue;
1243                         } else if (altmap)
1244                                 return -ENOMEM; /* no fallback */
1245                 } else if (pmd_large(*pmd)) {
1246                         vmemmap_verify((pte_t *)pmd, node, addr, next);
1247                         continue;
1248                 }
1249                 pr_warn_once("vmemmap: falling back to regular page backing\n");
1250                 if (vmemmap_populate_basepages(addr, next, node))
1251                         return -ENOMEM;
1252         }
1253         return 0;
1254 }
1255
1256 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
1257 {
1258         struct vmem_altmap *altmap = to_vmem_altmap(start);
1259         int err;
1260
1261         if (boot_cpu_has(X86_FEATURE_PSE))
1262                 err = vmemmap_populate_hugepages(start, end, node, altmap);
1263         else if (altmap) {
1264                 pr_err_once("%s: no cpu support for altmap allocations\n",
1265                                 __func__);
1266                 err = -ENOMEM;
1267         } else
1268                 err = vmemmap_populate_basepages(start, end, node);
1269         if (!err)
1270                 sync_global_pgds(start, end - 1, 0);
1271         return err;
1272 }
1273
1274 #if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HAVE_BOOTMEM_INFO_NODE)
1275 void register_page_bootmem_memmap(unsigned long section_nr,
1276                                   struct page *start_page, unsigned long size)
1277 {
1278         unsigned long addr = (unsigned long)start_page;
1279         unsigned long end = (unsigned long)(start_page + size);
1280         unsigned long next;
1281         pgd_t *pgd;
1282         pud_t *pud;
1283         pmd_t *pmd;
1284         unsigned int nr_pages;
1285         struct page *page;
1286
1287         for (; addr < end; addr = next) {
1288                 pte_t *pte = NULL;
1289
1290                 pgd = pgd_offset_k(addr);
1291                 if (pgd_none(*pgd)) {
1292                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1293                         continue;
1294                 }
1295                 get_page_bootmem(section_nr, pgd_page(*pgd), MIX_SECTION_INFO);
1296
1297                 pud = pud_offset(pgd, addr);
1298                 if (pud_none(*pud)) {
1299                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1300                         continue;
1301                 }
1302                 get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO);
1303
1304                 if (!boot_cpu_has(X86_FEATURE_PSE)) {
1305                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1306                         pmd = pmd_offset(pud, addr);
1307                         if (pmd_none(*pmd))
1308                                 continue;
1309                         get_page_bootmem(section_nr, pmd_page(*pmd),
1310                                          MIX_SECTION_INFO);
1311
1312                         pte = pte_offset_kernel(pmd, addr);
1313                         if (pte_none(*pte))
1314                                 continue;
1315                         get_page_bootmem(section_nr, pte_page(*pte),
1316                                          SECTION_INFO);
1317                 } else {
1318                         next = pmd_addr_end(addr, end);
1319
1320                         pmd = pmd_offset(pud, addr);
1321                         if (pmd_none(*pmd))
1322                                 continue;
1323
1324                         nr_pages = 1 << (get_order(PMD_SIZE));
1325                         page = pmd_page(*pmd);
1326                         while (nr_pages--)
1327                                 get_page_bootmem(section_nr, page++,
1328                                                  SECTION_INFO);
1329                 }
1330         }
1331 }
1332 #endif
1333
1334 void __meminit vmemmap_populate_print_last(void)
1335 {
1336         if (p_start) {
1337                 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1338                         addr_start, addr_end-1, p_start, p_end-1, node_start);
1339                 p_start = NULL;
1340                 p_end = NULL;
1341                 node_start = 0;
1342         }
1343 }
1344 #endif
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