x86: add after_bootmem flag for 32bit
[linux-2.6] / arch / x86 / mm / init_32.c
1 /*
2  *
3  *  Copyright (C) 1995  Linus Torvalds
4  *
5  *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
6  */
7
8 #include <linux/module.h>
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/hugetlb.h>
19 #include <linux/swap.h>
20 #include <linux/smp.h>
21 #include <linux/init.h>
22 #include <linux/highmem.h>
23 #include <linux/pagemap.h>
24 #include <linux/pfn.h>
25 #include <linux/poison.h>
26 #include <linux/bootmem.h>
27 #include <linux/slab.h>
28 #include <linux/proc_fs.h>
29 #include <linux/memory_hotplug.h>
30 #include <linux/initrd.h>
31 #include <linux/cpumask.h>
32
33 #include <asm/asm.h>
34 #include <asm/bios_ebda.h>
35 #include <asm/processor.h>
36 #include <asm/system.h>
37 #include <asm/uaccess.h>
38 #include <asm/pgtable.h>
39 #include <asm/dma.h>
40 #include <asm/fixmap.h>
41 #include <asm/e820.h>
42 #include <asm/apic.h>
43 #include <asm/bugs.h>
44 #include <asm/tlb.h>
45 #include <asm/tlbflush.h>
46 #include <asm/pgalloc.h>
47 #include <asm/sections.h>
48 #include <asm/paravirt.h>
49 #include <asm/setup.h>
50 #include <asm/cacheflush.h>
51 #include <asm/smp.h>
52
53 unsigned int __VMALLOC_RESERVE = 128 << 20;
54
55 unsigned long max_low_pfn_mapped;
56 unsigned long max_pfn_mapped;
57
58 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
59 unsigned long highstart_pfn, highend_pfn;
60
61 static noinline int do_test_wp_bit(void);
62
63
64 static unsigned long __initdata table_start;
65 static unsigned long __meminitdata table_end;
66 static unsigned long __meminitdata table_top;
67
68 static int __initdata after_init_bootmem;
69 int after_bootmem;
70
71 static __init void *alloc_low_page(unsigned long *phys)
72 {
73         unsigned long pfn = table_end++;
74         void *adr;
75
76         if (pfn >= table_top)
77                 panic("alloc_low_page: ran out of memory");
78
79         adr = __va(pfn * PAGE_SIZE);
80         memset(adr, 0, PAGE_SIZE);
81         *phys  = pfn * PAGE_SIZE;
82         return adr;
83 }
84
85 /*
86  * Creates a middle page table and puts a pointer to it in the
87  * given global directory entry. This only returns the gd entry
88  * in non-PAE compilation mode, since the middle layer is folded.
89  */
90 static pmd_t * __init one_md_table_init(pgd_t *pgd)
91 {
92         pud_t *pud;
93         pmd_t *pmd_table;
94
95 #ifdef CONFIG_X86_PAE
96         unsigned long phys;
97         if (!(pgd_val(*pgd) & _PAGE_PRESENT)) {
98                 if (after_init_bootmem)
99                         pmd_table = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE);
100                 else
101                         pmd_table = (pmd_t *)alloc_low_page(&phys);
102                 paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT);
103                 set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
104                 pud = pud_offset(pgd, 0);
105                 BUG_ON(pmd_table != pmd_offset(pud, 0));
106         }
107 #endif
108         pud = pud_offset(pgd, 0);
109         pmd_table = pmd_offset(pud, 0);
110
111         return pmd_table;
112 }
113
114 /*
115  * Create a page table and place a pointer to it in a middle page
116  * directory entry:
117  */
118 static pte_t * __init one_page_table_init(pmd_t *pmd)
119 {
120         if (!(pmd_val(*pmd) & _PAGE_PRESENT)) {
121                 pte_t *page_table = NULL;
122
123                 if (after_init_bootmem) {
124 #ifdef CONFIG_DEBUG_PAGEALLOC
125                         page_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);
126 #endif
127                         if (!page_table)
128                                 page_table =
129                                 (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE);
130                 } else {
131                         unsigned long phys;
132                         page_table = (pte_t *)alloc_low_page(&phys);
133                 }
134
135                 paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT);
136                 set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE));
137                 BUG_ON(page_table != pte_offset_kernel(pmd, 0));
138         }
139
140         return pte_offset_kernel(pmd, 0);
141 }
142
143 /*
144  * This function initializes a certain range of kernel virtual memory
145  * with new bootmem page tables, everywhere page tables are missing in
146  * the given range.
147  *
148  * NOTE: The pagetables are allocated contiguous on the physical space
149  * so we can cache the place of the first one and move around without
150  * checking the pgd every time.
151  */
152 static void __init
153 page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base)
154 {
155         int pgd_idx, pmd_idx;
156         unsigned long vaddr;
157         pgd_t *pgd;
158         pmd_t *pmd;
159
160         vaddr = start;
161         pgd_idx = pgd_index(vaddr);
162         pmd_idx = pmd_index(vaddr);
163         pgd = pgd_base + pgd_idx;
164
165         for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
166                 pmd = one_md_table_init(pgd);
167                 pmd = pmd + pmd_index(vaddr);
168                 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);
169                                                         pmd++, pmd_idx++) {
170                         one_page_table_init(pmd);
171
172                         vaddr += PMD_SIZE;
173                 }
174                 pmd_idx = 0;
175         }
176 }
177
178 static inline int is_kernel_text(unsigned long addr)
179 {
180         if (addr >= PAGE_OFFSET && addr <= (unsigned long)__init_end)
181                 return 1;
182         return 0;
183 }
184
185 /*
186  * This maps the physical memory to kernel virtual address space, a total
187  * of max_low_pfn pages, by creating page tables starting from address
188  * PAGE_OFFSET:
189  */
190 static void __init kernel_physical_mapping_init(pgd_t *pgd_base,
191                                                 unsigned long start_pfn,
192                                                 unsigned long end_pfn,
193                                                 int use_pse)
194 {
195         int pgd_idx, pmd_idx, pte_ofs;
196         unsigned long pfn;
197         pgd_t *pgd;
198         pmd_t *pmd;
199         pte_t *pte;
200         unsigned pages_2m, pages_4k;
201         int mapping_iter;
202
203         /*
204          * First iteration will setup identity mapping using large/small pages
205          * based on use_pse, with other attributes same as set by
206          * the early code in head_32.S
207          *
208          * Second iteration will setup the appropriate attributes (NX, GLOBAL..)
209          * as desired for the kernel identity mapping.
210          *
211          * This two pass mechanism conforms to the TLB app note which says:
212          *
213          *     "Software should not write to a paging-structure entry in a way
214          *      that would change, for any linear address, both the page size
215          *      and either the page frame or attributes."
216          */
217         mapping_iter = 1;
218
219         if (!cpu_has_pse)
220                 use_pse = 0;
221
222 repeat:
223         pages_2m = pages_4k = 0;
224         pfn = start_pfn;
225         pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
226         pgd = pgd_base + pgd_idx;
227         for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) {
228                 pmd = one_md_table_init(pgd);
229
230                 if (pfn >= end_pfn)
231                         continue;
232 #ifdef CONFIG_X86_PAE
233                 pmd_idx = pmd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
234                 pmd += pmd_idx;
235 #else
236                 pmd_idx = 0;
237 #endif
238                 for (; pmd_idx < PTRS_PER_PMD && pfn < end_pfn;
239                      pmd++, pmd_idx++) {
240                         unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET;
241
242                         /*
243                          * Map with big pages if possible, otherwise
244                          * create normal page tables:
245                          */
246                         if (use_pse) {
247                                 unsigned int addr2;
248                                 pgprot_t prot = PAGE_KERNEL_LARGE;
249                                 /*
250                                  * first pass will use the same initial
251                                  * identity mapping attribute + _PAGE_PSE.
252                                  */
253                                 pgprot_t init_prot =
254                                         __pgprot(PTE_IDENT_ATTR |
255                                                  _PAGE_PSE);
256
257                                 addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE +
258                                         PAGE_OFFSET + PAGE_SIZE-1;
259
260                                 if (is_kernel_text(addr) ||
261                                     is_kernel_text(addr2))
262                                         prot = PAGE_KERNEL_LARGE_EXEC;
263
264                                 pages_2m++;
265                                 if (mapping_iter == 1)
266                                         set_pmd(pmd, pfn_pmd(pfn, init_prot));
267                                 else
268                                         set_pmd(pmd, pfn_pmd(pfn, prot));
269
270                                 pfn += PTRS_PER_PTE;
271                                 continue;
272                         }
273                         pte = one_page_table_init(pmd);
274
275                         pte_ofs = pte_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
276                         pte += pte_ofs;
277                         for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn;
278                              pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) {
279                                 pgprot_t prot = PAGE_KERNEL;
280                                 /*
281                                  * first pass will use the same initial
282                                  * identity mapping attribute.
283                                  */
284                                 pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR);
285
286                                 if (is_kernel_text(addr))
287                                         prot = PAGE_KERNEL_EXEC;
288
289                                 pages_4k++;
290                                 if (mapping_iter == 1)
291                                         set_pte(pte, pfn_pte(pfn, init_prot));
292                                 else
293                                         set_pte(pte, pfn_pte(pfn, prot));
294                         }
295                 }
296         }
297         if (mapping_iter == 1) {
298                 /*
299                  * update direct mapping page count only in the first
300                  * iteration.
301                  */
302                 update_page_count(PG_LEVEL_2M, pages_2m);
303                 update_page_count(PG_LEVEL_4K, pages_4k);
304
305                 /*
306                  * local global flush tlb, which will flush the previous
307                  * mappings present in both small and large page TLB's.
308                  */
309                 __flush_tlb_all();
310
311                 /*
312                  * Second iteration will set the actual desired PTE attributes.
313                  */
314                 mapping_iter = 2;
315                 goto repeat;
316         }
317 }
318
319 /*
320  * devmem_is_allowed() checks to see if /dev/mem access to a certain address
321  * is valid. The argument is a physical page number.
322  *
323  *
324  * On x86, access has to be given to the first megabyte of ram because that area
325  * contains bios code and data regions used by X and dosemu and similar apps.
326  * Access has to be given to non-kernel-ram areas as well, these contain the PCI
327  * mmio resources as well as potential bios/acpi data regions.
328  */
329 int devmem_is_allowed(unsigned long pagenr)
330 {
331         if (pagenr <= 256)
332                 return 1;
333         if (!page_is_ram(pagenr))
334                 return 1;
335         return 0;
336 }
337
338 #ifdef CONFIG_HIGHMEM
339 pte_t *kmap_pte;
340 pgprot_t kmap_prot;
341
342 static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr)
343 {
344         return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
345                         vaddr), vaddr), vaddr);
346 }
347
348 static void __init kmap_init(void)
349 {
350         unsigned long kmap_vstart;
351
352         /*
353          * Cache the first kmap pte:
354          */
355         kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
356         kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
357
358         kmap_prot = PAGE_KERNEL;
359 }
360
361 static void __init permanent_kmaps_init(pgd_t *pgd_base)
362 {
363         unsigned long vaddr;
364         pgd_t *pgd;
365         pud_t *pud;
366         pmd_t *pmd;
367         pte_t *pte;
368
369         vaddr = PKMAP_BASE;
370         page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
371
372         pgd = swapper_pg_dir + pgd_index(vaddr);
373         pud = pud_offset(pgd, vaddr);
374         pmd = pmd_offset(pud, vaddr);
375         pte = pte_offset_kernel(pmd, vaddr);
376         pkmap_page_table = pte;
377 }
378
379 static void __init add_one_highpage_init(struct page *page, int pfn)
380 {
381         ClearPageReserved(page);
382         init_page_count(page);
383         __free_page(page);
384         totalhigh_pages++;
385 }
386
387 struct add_highpages_data {
388         unsigned long start_pfn;
389         unsigned long end_pfn;
390 };
391
392 static int __init add_highpages_work_fn(unsigned long start_pfn,
393                                          unsigned long end_pfn, void *datax)
394 {
395         int node_pfn;
396         struct page *page;
397         unsigned long final_start_pfn, final_end_pfn;
398         struct add_highpages_data *data;
399
400         data = (struct add_highpages_data *)datax;
401
402         final_start_pfn = max(start_pfn, data->start_pfn);
403         final_end_pfn = min(end_pfn, data->end_pfn);
404         if (final_start_pfn >= final_end_pfn)
405                 return 0;
406
407         for (node_pfn = final_start_pfn; node_pfn < final_end_pfn;
408              node_pfn++) {
409                 if (!pfn_valid(node_pfn))
410                         continue;
411                 page = pfn_to_page(node_pfn);
412                 add_one_highpage_init(page, node_pfn);
413         }
414
415         return 0;
416
417 }
418
419 void __init add_highpages_with_active_regions(int nid, unsigned long start_pfn,
420                                               unsigned long end_pfn)
421 {
422         struct add_highpages_data data;
423
424         data.start_pfn = start_pfn;
425         data.end_pfn = end_pfn;
426
427         work_with_active_regions(nid, add_highpages_work_fn, &data);
428 }
429
430 #ifndef CONFIG_NUMA
431 static void __init set_highmem_pages_init(void)
432 {
433         add_highpages_with_active_regions(0, highstart_pfn, highend_pfn);
434
435         totalram_pages += totalhigh_pages;
436 }
437 #endif /* !CONFIG_NUMA */
438
439 #else
440 # define kmap_init()                            do { } while (0)
441 # define permanent_kmaps_init(pgd_base)         do { } while (0)
442 # define set_highmem_pages_init()       do { } while (0)
443 #endif /* CONFIG_HIGHMEM */
444
445 void __init native_pagetable_setup_start(pgd_t *base)
446 {
447         unsigned long pfn, va;
448         pgd_t *pgd;
449         pud_t *pud;
450         pmd_t *pmd;
451         pte_t *pte;
452
453         /*
454          * Remove any mappings which extend past the end of physical
455          * memory from the boot time page table:
456          */
457         for (pfn = max_low_pfn + 1; pfn < 1<<(32-PAGE_SHIFT); pfn++) {
458                 va = PAGE_OFFSET + (pfn<<PAGE_SHIFT);
459                 pgd = base + pgd_index(va);
460                 if (!pgd_present(*pgd))
461                         break;
462
463                 pud = pud_offset(pgd, va);
464                 pmd = pmd_offset(pud, va);
465                 if (!pmd_present(*pmd))
466                         break;
467
468                 pte = pte_offset_kernel(pmd, va);
469                 if (!pte_present(*pte))
470                         break;
471
472                 pte_clear(NULL, va, pte);
473         }
474         paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT);
475 }
476
477 void __init native_pagetable_setup_done(pgd_t *base)
478 {
479 }
480
481 /*
482  * Build a proper pagetable for the kernel mappings.  Up until this
483  * point, we've been running on some set of pagetables constructed by
484  * the boot process.
485  *
486  * If we're booting on native hardware, this will be a pagetable
487  * constructed in arch/x86/kernel/head_32.S.  The root of the
488  * pagetable will be swapper_pg_dir.
489  *
490  * If we're booting paravirtualized under a hypervisor, then there are
491  * more options: we may already be running PAE, and the pagetable may
492  * or may not be based in swapper_pg_dir.  In any case,
493  * paravirt_pagetable_setup_start() will set up swapper_pg_dir
494  * appropriately for the rest of the initialization to work.
495  *
496  * In general, pagetable_init() assumes that the pagetable may already
497  * be partially populated, and so it avoids stomping on any existing
498  * mappings.
499  */
500 static void __init early_ioremap_page_table_range_init(pgd_t *pgd_base)
501 {
502         unsigned long vaddr, end;
503
504         /*
505          * Fixed mappings, only the page table structure has to be
506          * created - mappings will be set by set_fixmap():
507          */
508         early_ioremap_clear();
509         vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
510         end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
511         page_table_range_init(vaddr, end, pgd_base);
512         early_ioremap_reset();
513 }
514
515 static void __init pagetable_init(void)
516 {
517         pgd_t *pgd_base = swapper_pg_dir;
518
519         permanent_kmaps_init(pgd_base);
520 }
521
522 #ifdef CONFIG_ACPI_SLEEP
523 /*
524  * ACPI suspend needs this for resume, because things like the intel-agp
525  * driver might have split up a kernel 4MB mapping.
526  */
527 char swsusp_pg_dir[PAGE_SIZE]
528         __attribute__ ((aligned(PAGE_SIZE)));
529
530 static inline void save_pg_dir(void)
531 {
532         memcpy(swsusp_pg_dir, swapper_pg_dir, PAGE_SIZE);
533 }
534 #else /* !CONFIG_ACPI_SLEEP */
535 static inline void save_pg_dir(void)
536 {
537 }
538 #endif /* !CONFIG_ACPI_SLEEP */
539
540 void zap_low_mappings(void)
541 {
542         int i;
543
544         /*
545          * Zap initial low-memory mappings.
546          *
547          * Note that "pgd_clear()" doesn't do it for
548          * us, because pgd_clear() is a no-op on i386.
549          */
550         for (i = 0; i < KERNEL_PGD_BOUNDARY; i++) {
551 #ifdef CONFIG_X86_PAE
552                 set_pgd(swapper_pg_dir+i, __pgd(1 + __pa(empty_zero_page)));
553 #else
554                 set_pgd(swapper_pg_dir+i, __pgd(0));
555 #endif
556         }
557         flush_tlb_all();
558 }
559
560 int nx_enabled;
561
562 pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL | _PAGE_IOMAP);
563 EXPORT_SYMBOL_GPL(__supported_pte_mask);
564
565 #ifdef CONFIG_X86_PAE
566
567 static int disable_nx __initdata;
568
569 /*
570  * noexec = on|off
571  *
572  * Control non executable mappings.
573  *
574  * on      Enable
575  * off     Disable
576  */
577 static int __init noexec_setup(char *str)
578 {
579         if (!str || !strcmp(str, "on")) {
580                 if (cpu_has_nx) {
581                         __supported_pte_mask |= _PAGE_NX;
582                         disable_nx = 0;
583                 }
584         } else {
585                 if (!strcmp(str, "off")) {
586                         disable_nx = 1;
587                         __supported_pte_mask &= ~_PAGE_NX;
588                 } else {
589                         return -EINVAL;
590                 }
591         }
592
593         return 0;
594 }
595 early_param("noexec", noexec_setup);
596
597 static void __init set_nx(void)
598 {
599         unsigned int v[4], l, h;
600
601         if (cpu_has_pae && (cpuid_eax(0x80000000) > 0x80000001)) {
602                 cpuid(0x80000001, &v[0], &v[1], &v[2], &v[3]);
603
604                 if ((v[3] & (1 << 20)) && !disable_nx) {
605                         rdmsr(MSR_EFER, l, h);
606                         l |= EFER_NX;
607                         wrmsr(MSR_EFER, l, h);
608                         nx_enabled = 1;
609                         __supported_pte_mask |= _PAGE_NX;
610                 }
611         }
612 }
613 #endif
614
615 /* user-defined highmem size */
616 static unsigned int highmem_pages = -1;
617
618 /*
619  * highmem=size forces highmem to be exactly 'size' bytes.
620  * This works even on boxes that have no highmem otherwise.
621  * This also works to reduce highmem size on bigger boxes.
622  */
623 static int __init parse_highmem(char *arg)
624 {
625         if (!arg)
626                 return -EINVAL;
627
628         highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT;
629         return 0;
630 }
631 early_param("highmem", parse_highmem);
632
633 /*
634  * Determine low and high memory ranges:
635  */
636 void __init find_low_pfn_range(void)
637 {
638         /* it could update max_pfn */
639
640         /* max_low_pfn is 0, we already have early_res support */
641
642         max_low_pfn = max_pfn;
643         if (max_low_pfn > MAXMEM_PFN) {
644                 if (highmem_pages == -1)
645                         highmem_pages = max_pfn - MAXMEM_PFN;
646                 if (highmem_pages + MAXMEM_PFN < max_pfn)
647                         max_pfn = MAXMEM_PFN + highmem_pages;
648                 if (highmem_pages + MAXMEM_PFN > max_pfn) {
649                         printk(KERN_WARNING "only %luMB highmem pages "
650                                 "available, ignoring highmem size of %uMB.\n",
651                                 pages_to_mb(max_pfn - MAXMEM_PFN),
652                                 pages_to_mb(highmem_pages));
653                         highmem_pages = 0;
654                 }
655                 max_low_pfn = MAXMEM_PFN;
656 #ifndef CONFIG_HIGHMEM
657                 /* Maximum memory usable is what is directly addressable */
658                 printk(KERN_WARNING "Warning only %ldMB will be used.\n",
659                                         MAXMEM>>20);
660                 if (max_pfn > MAX_NONPAE_PFN)
661                         printk(KERN_WARNING
662                                  "Use a HIGHMEM64G enabled kernel.\n");
663                 else
664                         printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");
665                 max_pfn = MAXMEM_PFN;
666 #else /* !CONFIG_HIGHMEM */
667 #ifndef CONFIG_HIGHMEM64G
668                 if (max_pfn > MAX_NONPAE_PFN) {
669                         max_pfn = MAX_NONPAE_PFN;
670                         printk(KERN_WARNING "Warning only 4GB will be used."
671                                 "Use a HIGHMEM64G enabled kernel.\n");
672                 }
673 #endif /* !CONFIG_HIGHMEM64G */
674 #endif /* !CONFIG_HIGHMEM */
675         } else {
676                 if (highmem_pages == -1)
677                         highmem_pages = 0;
678 #ifdef CONFIG_HIGHMEM
679                 if (highmem_pages >= max_pfn) {
680                         printk(KERN_ERR "highmem size specified (%uMB) is "
681                                 "bigger than pages available (%luMB)!.\n",
682                                 pages_to_mb(highmem_pages),
683                                 pages_to_mb(max_pfn));
684                         highmem_pages = 0;
685                 }
686                 if (highmem_pages) {
687                         if (max_low_pfn - highmem_pages <
688                             64*1024*1024/PAGE_SIZE){
689                                 printk(KERN_ERR "highmem size %uMB results in "
690                                 "smaller than 64MB lowmem, ignoring it.\n"
691                                         , pages_to_mb(highmem_pages));
692                                 highmem_pages = 0;
693                         }
694                         max_low_pfn -= highmem_pages;
695                 }
696 #else
697                 if (highmem_pages)
698                         printk(KERN_ERR "ignoring highmem size on non-highmem"
699                                         " kernel!\n");
700 #endif
701         }
702 }
703
704 #ifndef CONFIG_NEED_MULTIPLE_NODES
705 void __init initmem_init(unsigned long start_pfn,
706                                   unsigned long end_pfn)
707 {
708 #ifdef CONFIG_HIGHMEM
709         highstart_pfn = highend_pfn = max_pfn;
710         if (max_pfn > max_low_pfn)
711                 highstart_pfn = max_low_pfn;
712         memory_present(0, 0, highend_pfn);
713         e820_register_active_regions(0, 0, highend_pfn);
714         printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
715                 pages_to_mb(highend_pfn - highstart_pfn));
716         num_physpages = highend_pfn;
717         high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1;
718 #else
719         memory_present(0, 0, max_low_pfn);
720         e820_register_active_regions(0, 0, max_low_pfn);
721         num_physpages = max_low_pfn;
722         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1;
723 #endif
724 #ifdef CONFIG_FLATMEM
725         max_mapnr = num_physpages;
726 #endif
727         printk(KERN_NOTICE "%ldMB LOWMEM available.\n",
728                         pages_to_mb(max_low_pfn));
729
730         setup_bootmem_allocator();
731 }
732 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
733
734 static void __init zone_sizes_init(void)
735 {
736         unsigned long max_zone_pfns[MAX_NR_ZONES];
737         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
738         max_zone_pfns[ZONE_DMA] =
739                 virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
740         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
741 #ifdef CONFIG_HIGHMEM
742         max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
743 #endif
744
745         free_area_init_nodes(max_zone_pfns);
746 }
747
748 void __init setup_bootmem_allocator(void)
749 {
750         int i;
751         unsigned long bootmap_size, bootmap;
752         /*
753          * Initialize the boot-time allocator (with low memory only):
754          */
755         bootmap_size = bootmem_bootmap_pages(max_low_pfn)<<PAGE_SHIFT;
756         bootmap = find_e820_area(min_low_pfn<<PAGE_SHIFT,
757                                  max_pfn_mapped<<PAGE_SHIFT, bootmap_size,
758                                  PAGE_SIZE);
759         if (bootmap == -1L)
760                 panic("Cannot find bootmem map of size %ld\n", bootmap_size);
761         reserve_early(bootmap, bootmap + bootmap_size, "BOOTMAP");
762
763         /* don't touch min_low_pfn */
764         bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap >> PAGE_SHIFT,
765                                          min_low_pfn, max_low_pfn);
766         printk(KERN_INFO "  mapped low ram: 0 - %08lx\n",
767                  max_pfn_mapped<<PAGE_SHIFT);
768         printk(KERN_INFO "  low ram: %08lx - %08lx\n",
769                  min_low_pfn<<PAGE_SHIFT, max_low_pfn<<PAGE_SHIFT);
770         printk(KERN_INFO "  bootmap %08lx - %08lx\n",
771                  bootmap, bootmap + bootmap_size);
772         for_each_online_node(i)
773                 free_bootmem_with_active_regions(i, max_low_pfn);
774         early_res_to_bootmem(0, max_low_pfn<<PAGE_SHIFT);
775
776         after_init_bootmem = 1;
777 }
778
779 static void __init find_early_table_space(unsigned long end, int use_pse)
780 {
781         unsigned long puds, pmds, ptes, tables, start;
782
783         puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
784         tables = PAGE_ALIGN(puds * sizeof(pud_t));
785
786         pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
787         tables += PAGE_ALIGN(pmds * sizeof(pmd_t));
788
789         if (use_pse) {
790                 unsigned long extra;
791
792                 extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT);
793                 extra += PMD_SIZE;
794                 ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT;
795         } else
796                 ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT;
797
798         tables += PAGE_ALIGN(ptes * sizeof(pte_t));
799
800         /* for fixmap */
801         tables += PAGE_SIZE * 2;
802
803         /*
804          * RED-PEN putting page tables only on node 0 could
805          * cause a hotspot and fill up ZONE_DMA. The page tables
806          * need roughly 0.5KB per GB.
807          */
808         start = 0x7000;
809         table_start = find_e820_area(start, max_pfn_mapped<<PAGE_SHIFT,
810                                         tables, PAGE_SIZE);
811         if (table_start == -1UL)
812                 panic("Cannot find space for the kernel page tables");
813
814         table_start >>= PAGE_SHIFT;
815         table_end = table_start;
816         table_top = table_start + (tables>>PAGE_SHIFT);
817
818         printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n",
819                 end, table_start << PAGE_SHIFT,
820                 (table_start << PAGE_SHIFT) + tables);
821 }
822
823 unsigned long __init_refok init_memory_mapping(unsigned long start,
824                                                 unsigned long end)
825 {
826         pgd_t *pgd_base = swapper_pg_dir;
827         unsigned long start_pfn, end_pfn;
828         unsigned long big_page_start;
829 #ifdef CONFIG_DEBUG_PAGEALLOC
830         /*
831          * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
832          * This will simplify cpa(), which otherwise needs to support splitting
833          * large pages into small in interrupt context, etc.
834          */
835         int use_pse = 0;
836 #else
837         int use_pse = cpu_has_pse;
838 #endif
839
840         /*
841          * Find space for the kernel direct mapping tables.
842          */
843         if (!after_init_bootmem)
844                 find_early_table_space(end, use_pse);
845
846 #ifdef CONFIG_X86_PAE
847         set_nx();
848         if (nx_enabled)
849                 printk(KERN_INFO "NX (Execute Disable) protection: active\n");
850 #endif
851
852         /* Enable PSE if available */
853         if (cpu_has_pse)
854                 set_in_cr4(X86_CR4_PSE);
855
856         /* Enable PGE if available */
857         if (cpu_has_pge) {
858                 set_in_cr4(X86_CR4_PGE);
859                 __supported_pte_mask |= _PAGE_GLOBAL;
860         }
861
862         /*
863          * Don't use a large page for the first 2/4MB of memory
864          * because there are often fixed size MTRRs in there
865          * and overlapping MTRRs into large pages can cause
866          * slowdowns.
867          */
868         big_page_start = PMD_SIZE;
869
870         if (start < big_page_start) {
871                 start_pfn = start >> PAGE_SHIFT;
872                 end_pfn = min(big_page_start>>PAGE_SHIFT, end>>PAGE_SHIFT);
873         } else {
874                 /* head is not big page alignment ? */
875                 start_pfn = start >> PAGE_SHIFT;
876                 end_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT)
877                                  << (PMD_SHIFT - PAGE_SHIFT);
878         }
879         if (start_pfn < end_pfn)
880                 kernel_physical_mapping_init(pgd_base, start_pfn, end_pfn, 0);
881
882         /* big page range */
883         start_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT)
884                          << (PMD_SHIFT - PAGE_SHIFT);
885         if (start_pfn < (big_page_start >> PAGE_SHIFT))
886                 start_pfn =  big_page_start >> PAGE_SHIFT;
887         end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
888         if (start_pfn < end_pfn)
889                 kernel_physical_mapping_init(pgd_base, start_pfn, end_pfn,
890                                              use_pse);
891
892         /* tail is not big page alignment ? */
893         start_pfn = end_pfn;
894         if (start_pfn > (big_page_start>>PAGE_SHIFT)) {
895                 end_pfn = end >> PAGE_SHIFT;
896                 if (start_pfn < end_pfn)
897                         kernel_physical_mapping_init(pgd_base, start_pfn,
898                                                          end_pfn, 0);
899         }
900
901         early_ioremap_page_table_range_init(pgd_base);
902
903         load_cr3(swapper_pg_dir);
904
905         __flush_tlb_all();
906
907         if (!after_init_bootmem)
908                 reserve_early(table_start << PAGE_SHIFT,
909                                  table_end << PAGE_SHIFT, "PGTABLE");
910
911         if (!after_init_bootmem)
912                 early_memtest(start, end);
913
914         return end >> PAGE_SHIFT;
915 }
916
917
918 /*
919  * paging_init() sets up the page tables - note that the first 8MB are
920  * already mapped by head.S.
921  *
922  * This routines also unmaps the page at virtual kernel address 0, so
923  * that we can trap those pesky NULL-reference errors in the kernel.
924  */
925 void __init paging_init(void)
926 {
927         pagetable_init();
928
929         __flush_tlb_all();
930
931         kmap_init();
932
933         /*
934          * NOTE: at this point the bootmem allocator is fully available.
935          */
936         sparse_init();
937         zone_sizes_init();
938 }
939
940 /*
941  * Test if the WP bit works in supervisor mode. It isn't supported on 386's
942  * and also on some strange 486's. All 586+'s are OK. This used to involve
943  * black magic jumps to work around some nasty CPU bugs, but fortunately the
944  * switch to using exceptions got rid of all that.
945  */
946 static void __init test_wp_bit(void)
947 {
948         printk(KERN_INFO
949   "Checking if this processor honours the WP bit even in supervisor mode...");
950
951         /* Any page-aligned address will do, the test is non-destructive */
952         __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_READONLY);
953         boot_cpu_data.wp_works_ok = do_test_wp_bit();
954         clear_fixmap(FIX_WP_TEST);
955
956         if (!boot_cpu_data.wp_works_ok) {
957                 printk(KERN_CONT "No.\n");
958 #ifdef CONFIG_X86_WP_WORKS_OK
959                 panic(
960   "This kernel doesn't support CPU's with broken WP. Recompile it for a 386!");
961 #endif
962         } else {
963                 printk(KERN_CONT "Ok.\n");
964         }
965 }
966
967 static struct kcore_list kcore_mem, kcore_vmalloc;
968
969 void __init mem_init(void)
970 {
971         int codesize, reservedpages, datasize, initsize;
972         int tmp;
973
974         start_periodic_check_for_corruption();
975
976 #ifdef CONFIG_FLATMEM
977         BUG_ON(!mem_map);
978 #endif
979         /* this will put all low memory onto the freelists */
980         totalram_pages += free_all_bootmem();
981
982         reservedpages = 0;
983         for (tmp = 0; tmp < max_low_pfn; tmp++)
984                 /*
985                  * Only count reserved RAM pages:
986                  */
987                 if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp)))
988                         reservedpages++;
989
990         set_highmem_pages_init();
991
992         after_bootmem = 1;
993
994         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
995         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
996         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
997
998         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
999         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
1000                    VMALLOC_END-VMALLOC_START);
1001
1002         printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
1003                         "%dk reserved, %dk data, %dk init, %ldk highmem)\n",
1004                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
1005                 num_physpages << (PAGE_SHIFT-10),
1006                 codesize >> 10,
1007                 reservedpages << (PAGE_SHIFT-10),
1008                 datasize >> 10,
1009                 initsize >> 10,
1010                 (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10))
1011                );
1012
1013         printk(KERN_INFO "virtual kernel memory layout:\n"
1014                 "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
1015 #ifdef CONFIG_HIGHMEM
1016                 "    pkmap   : 0x%08lx - 0x%08lx   (%4ld kB)\n"
1017 #endif
1018                 "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
1019                 "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
1020                 "      .init : 0x%08lx - 0x%08lx   (%4ld kB)\n"
1021                 "      .data : 0x%08lx - 0x%08lx   (%4ld kB)\n"
1022                 "      .text : 0x%08lx - 0x%08lx   (%4ld kB)\n",
1023                 FIXADDR_START, FIXADDR_TOP,
1024                 (FIXADDR_TOP - FIXADDR_START) >> 10,
1025
1026 #ifdef CONFIG_HIGHMEM
1027                 PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
1028                 (LAST_PKMAP*PAGE_SIZE) >> 10,
1029 #endif
1030
1031                 VMALLOC_START, VMALLOC_END,
1032                 (VMALLOC_END - VMALLOC_START) >> 20,
1033
1034                 (unsigned long)__va(0), (unsigned long)high_memory,
1035                 ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
1036
1037                 (unsigned long)&__init_begin, (unsigned long)&__init_end,
1038                 ((unsigned long)&__init_end -
1039                  (unsigned long)&__init_begin) >> 10,
1040
1041                 (unsigned long)&_etext, (unsigned long)&_edata,
1042                 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
1043
1044                 (unsigned long)&_text, (unsigned long)&_etext,
1045                 ((unsigned long)&_etext - (unsigned long)&_text) >> 10);
1046
1047 #ifdef CONFIG_HIGHMEM
1048         BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE        > FIXADDR_START);
1049         BUG_ON(VMALLOC_END                              > PKMAP_BASE);
1050 #endif
1051         BUG_ON(VMALLOC_START                            > VMALLOC_END);
1052         BUG_ON((unsigned long)high_memory               > VMALLOC_START);
1053
1054         if (boot_cpu_data.wp_works_ok < 0)
1055                 test_wp_bit();
1056
1057         save_pg_dir();
1058         zap_low_mappings();
1059 }
1060
1061 #ifdef CONFIG_MEMORY_HOTPLUG
1062 int arch_add_memory(int nid, u64 start, u64 size)
1063 {
1064         struct pglist_data *pgdata = NODE_DATA(nid);
1065         struct zone *zone = pgdata->node_zones + ZONE_HIGHMEM;
1066         unsigned long start_pfn = start >> PAGE_SHIFT;
1067         unsigned long nr_pages = size >> PAGE_SHIFT;
1068
1069         return __add_pages(zone, start_pfn, nr_pages);
1070 }
1071 #endif
1072
1073 /*
1074  * This function cannot be __init, since exceptions don't work in that
1075  * section.  Put this after the callers, so that it cannot be inlined.
1076  */
1077 static noinline int do_test_wp_bit(void)
1078 {
1079         char tmp_reg;
1080         int flag;
1081
1082         __asm__ __volatile__(
1083                 "       movb %0, %1     \n"
1084                 "1:     movb %1, %0     \n"
1085                 "       xorl %2, %2     \n"
1086                 "2:                     \n"
1087                 _ASM_EXTABLE(1b,2b)
1088                 :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)),
1089                  "=q" (tmp_reg),
1090                  "=r" (flag)
1091                 :"2" (1)
1092                 :"memory");
1093
1094         return flag;
1095 }
1096
1097 #ifdef CONFIG_DEBUG_RODATA
1098 const int rodata_test_data = 0xC3;
1099 EXPORT_SYMBOL_GPL(rodata_test_data);
1100
1101 void mark_rodata_ro(void)
1102 {
1103         unsigned long start = PFN_ALIGN(_text);
1104         unsigned long size = PFN_ALIGN(_etext) - start;
1105
1106 #ifndef CONFIG_DYNAMIC_FTRACE
1107         /* Dynamic tracing modifies the kernel text section */
1108         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
1109         printk(KERN_INFO "Write protecting the kernel text: %luk\n",
1110                 size >> 10);
1111
1112 #ifdef CONFIG_CPA_DEBUG
1113         printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n",
1114                 start, start+size);
1115         set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT);
1116
1117         printk(KERN_INFO "Testing CPA: write protecting again\n");
1118         set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT);
1119 #endif
1120 #endif /* CONFIG_DYNAMIC_FTRACE */
1121
1122         start += size;
1123         size = (unsigned long)__end_rodata - start;
1124         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
1125         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
1126                 size >> 10);
1127         rodata_test();
1128
1129 #ifdef CONFIG_CPA_DEBUG
1130         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size);
1131         set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
1132
1133         printk(KERN_INFO "Testing CPA: write protecting again\n");
1134         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
1135 #endif
1136 }
1137 #endif
1138
1139 void free_init_pages(char *what, unsigned long begin, unsigned long end)
1140 {
1141 #ifdef CONFIG_DEBUG_PAGEALLOC
1142         /*
1143          * If debugging page accesses then do not free this memory but
1144          * mark them not present - any buggy init-section access will
1145          * create a kernel page fault:
1146          */
1147         printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
1148                 begin, PAGE_ALIGN(end));
1149         set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
1150 #else
1151         unsigned long addr;
1152
1153         /*
1154          * We just marked the kernel text read only above, now that
1155          * we are going to free part of that, we need to make that
1156          * writeable first.
1157          */
1158         set_memory_rw(begin, (end - begin) >> PAGE_SHIFT);
1159
1160         for (addr = begin; addr < end; addr += PAGE_SIZE) {
1161                 ClearPageReserved(virt_to_page(addr));
1162                 init_page_count(virt_to_page(addr));
1163                 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
1164                 free_page(addr);
1165                 totalram_pages++;
1166         }
1167         printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
1168 #endif
1169 }
1170
1171 void free_initmem(void)
1172 {
1173         free_init_pages("unused kernel memory",
1174                         (unsigned long)(&__init_begin),
1175                         (unsigned long)(&__init_end));
1176 }
1177
1178 #ifdef CONFIG_BLK_DEV_INITRD
1179 void free_initrd_mem(unsigned long start, unsigned long end)
1180 {
1181         free_init_pages("initrd memory", start, end);
1182 }
1183 #endif
1184
1185 int __init reserve_bootmem_generic(unsigned long phys, unsigned long len,
1186                                    int flags)
1187 {
1188         return reserve_bootmem(phys, len, flags);
1189 }