Merge git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6
[linux-2.6.git] / 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/pci.h>
25 #include <linux/pfn.h>
26 #include <linux/poison.h>
27 #include <linux/bootmem.h>
28 #include <linux/slab.h>
29 #include <linux/proc_fs.h>
30 #include <linux/memory_hotplug.h>
31 #include <linux/initrd.h>
32 #include <linux/cpumask.h>
33
34 #include <asm/asm.h>
35 #include <asm/bios_ebda.h>
36 #include <asm/processor.h>
37 #include <asm/system.h>
38 #include <asm/uaccess.h>
39 #include <asm/pgtable.h>
40 #include <asm/dma.h>
41 #include <asm/fixmap.h>
42 #include <asm/e820.h>
43 #include <asm/apic.h>
44 #include <asm/bugs.h>
45 #include <asm/tlb.h>
46 #include <asm/tlbflush.h>
47 #include <asm/pgalloc.h>
48 #include <asm/sections.h>
49 #include <asm/paravirt.h>
50 #include <asm/setup.h>
51 #include <asm/cacheflush.h>
52 #include <asm/smp.h>
53
54 unsigned int __VMALLOC_RESERVE = 128 << 20;
55
56 unsigned long max_low_pfn_mapped;
57 unsigned long max_pfn_mapped;
58
59 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
60 unsigned long highstart_pfn, highend_pfn;
61
62 static noinline int do_test_wp_bit(void);
63
64
65 static unsigned long __initdata table_start;
66 static unsigned long __meminitdata table_end;
67 static unsigned long __meminitdata table_top;
68
69 static int __initdata after_init_bootmem;
70
71 static __init void *alloc_low_page(void)
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         return adr;
82 }
83
84 /*
85  * Creates a middle page table and puts a pointer to it in the
86  * given global directory entry. This only returns the gd entry
87  * in non-PAE compilation mode, since the middle layer is folded.
88  */
89 static pmd_t * __init one_md_table_init(pgd_t *pgd)
90 {
91         pud_t *pud;
92         pmd_t *pmd_table;
93
94 #ifdef CONFIG_X86_PAE
95         if (!(pgd_val(*pgd) & _PAGE_PRESENT)) {
96                 if (after_init_bootmem)
97                         pmd_table = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE);
98                 else
99                         pmd_table = (pmd_t *)alloc_low_page();
100                 paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT);
101                 set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
102                 pud = pud_offset(pgd, 0);
103                 BUG_ON(pmd_table != pmd_offset(pud, 0));
104
105                 return pmd_table;
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                         page_table = (pte_t *)alloc_low_page();
132
133                 paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT);
134                 set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE));
135                 BUG_ON(page_table != pte_offset_kernel(pmd, 0));
136         }
137
138         return pte_offset_kernel(pmd, 0);
139 }
140
141 /*
142  * This function initializes a certain range of kernel virtual memory
143  * with new bootmem page tables, everywhere page tables are missing in
144  * the given range.
145  *
146  * NOTE: The pagetables are allocated contiguous on the physical space
147  * so we can cache the place of the first one and move around without
148  * checking the pgd every time.
149  */
150 static void __init
151 page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base)
152 {
153         int pgd_idx, pmd_idx;
154         unsigned long vaddr;
155         pgd_t *pgd;
156         pmd_t *pmd;
157
158         vaddr = start;
159         pgd_idx = pgd_index(vaddr);
160         pmd_idx = pmd_index(vaddr);
161         pgd = pgd_base + pgd_idx;
162
163         for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
164                 pmd = one_md_table_init(pgd);
165                 pmd = pmd + pmd_index(vaddr);
166                 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);
167                                                         pmd++, pmd_idx++) {
168                         one_page_table_init(pmd);
169
170                         vaddr += PMD_SIZE;
171                 }
172                 pmd_idx = 0;
173         }
174 }
175
176 static inline int is_kernel_text(unsigned long addr)
177 {
178         if (addr >= PAGE_OFFSET && addr <= (unsigned long)__init_end)
179                 return 1;
180         return 0;
181 }
182
183 /*
184  * This maps the physical memory to kernel virtual address space, a total
185  * of max_low_pfn pages, by creating page tables starting from address
186  * PAGE_OFFSET:
187  */
188 static void __init kernel_physical_mapping_init(pgd_t *pgd_base,
189                                                 unsigned long start_pfn,
190                                                 unsigned long end_pfn,
191                                                 int use_pse)
192 {
193         int pgd_idx, pmd_idx, pte_ofs;
194         unsigned long pfn;
195         pgd_t *pgd;
196         pmd_t *pmd;
197         pte_t *pte;
198         unsigned pages_2m, pages_4k;
199         int mapping_iter;
200
201         /*
202          * First iteration will setup identity mapping using large/small pages
203          * based on use_pse, with other attributes same as set by
204          * the early code in head_32.S
205          *
206          * Second iteration will setup the appropriate attributes (NX, GLOBAL..)
207          * as desired for the kernel identity mapping.
208          *
209          * This two pass mechanism conforms to the TLB app note which says:
210          *
211          *     "Software should not write to a paging-structure entry in a way
212          *      that would change, for any linear address, both the page size
213          *      and either the page frame or attributes."
214          */
215         mapping_iter = 1;
216
217         if (!cpu_has_pse)
218                 use_pse = 0;
219
220 repeat:
221         pages_2m = pages_4k = 0;
222         pfn = start_pfn;
223         pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
224         pgd = pgd_base + pgd_idx;
225         for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) {
226                 pmd = one_md_table_init(pgd);
227
228                 if (pfn >= end_pfn)
229                         continue;
230 #ifdef CONFIG_X86_PAE
231                 pmd_idx = pmd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
232                 pmd += pmd_idx;
233 #else
234                 pmd_idx = 0;
235 #endif
236                 for (; pmd_idx < PTRS_PER_PMD && pfn < end_pfn;
237                      pmd++, pmd_idx++) {
238                         unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET;
239
240                         /*
241                          * Map with big pages if possible, otherwise
242                          * create normal page tables:
243                          */
244                         if (use_pse) {
245                                 unsigned int addr2;
246                                 pgprot_t prot = PAGE_KERNEL_LARGE;
247                                 /*
248                                  * first pass will use the same initial
249                                  * identity mapping attribute + _PAGE_PSE.
250                                  */
251                                 pgprot_t init_prot =
252                                         __pgprot(PTE_IDENT_ATTR |
253                                                  _PAGE_PSE);
254
255                                 addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE +
256                                         PAGE_OFFSET + PAGE_SIZE-1;
257
258                                 if (is_kernel_text(addr) ||
259                                     is_kernel_text(addr2))
260                                         prot = PAGE_KERNEL_LARGE_EXEC;
261
262                                 pages_2m++;
263                                 if (mapping_iter == 1)
264                                         set_pmd(pmd, pfn_pmd(pfn, init_prot));
265                                 else
266                                         set_pmd(pmd, pfn_pmd(pfn, prot));
267
268                                 pfn += PTRS_PER_PTE;
269                                 continue;
270                         }
271                         pte = one_page_table_init(pmd);
272
273                         pte_ofs = pte_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
274                         pte += pte_ofs;
275                         for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn;
276                              pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) {
277                                 pgprot_t prot = PAGE_KERNEL;
278                                 /*
279                                  * first pass will use the same initial
280                                  * identity mapping attribute.
281                                  */
282                                 pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR);
283
284                                 if (is_kernel_text(addr))
285                                         prot = PAGE_KERNEL_EXEC;
286
287                                 pages_4k++;
288                                 if (mapping_iter == 1)
289                                         set_pte(pte, pfn_pte(pfn, init_prot));
290                                 else
291                                         set_pte(pte, pfn_pte(pfn, prot));
292                         }
293                 }
294         }
295         if (mapping_iter == 1) {
296                 /*
297                  * update direct mapping page count only in the first
298                  * iteration.
299                  */
300                 update_page_count(PG_LEVEL_2M, pages_2m);
301                 update_page_count(PG_LEVEL_4K, pages_4k);
302
303                 /*
304                  * local global flush tlb, which will flush the previous
305                  * mappings present in both small and large page TLB's.
306                  */
307                 __flush_tlb_all();
308
309                 /*
310                  * Second iteration will set the actual desired PTE attributes.
311                  */
312                 mapping_iter = 2;
313                 goto repeat;
314         }
315 }
316
317 /*
318  * devmem_is_allowed() checks to see if /dev/mem access to a certain address
319  * is valid. The argument is a physical page number.
320  *
321  *
322  * On x86, access has to be given to the first megabyte of ram because that area
323  * contains bios code and data regions used by X and dosemu and similar apps.
324  * Access has to be given to non-kernel-ram areas as well, these contain the PCI
325  * mmio resources as well as potential bios/acpi data regions.
326  */
327 int devmem_is_allowed(unsigned long pagenr)
328 {
329         if (pagenr <= 256)
330                 return 1;
331         if (iomem_is_exclusive(pagenr << PAGE_SHIFT))
332                 return 0;
333         if (!page_is_ram(pagenr))
334                 return 1;
335         return 0;
336 }
337
338 pte_t *kmap_pte;
339 pgprot_t kmap_prot;
340
341 static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr)
342 {
343         return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
344                         vaddr), vaddr), vaddr);
345 }
346
347 static void __init kmap_init(void)
348 {
349         unsigned long kmap_vstart;
350
351         /*
352          * Cache the first kmap pte:
353          */
354         kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
355         kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
356
357         kmap_prot = PAGE_KERNEL;
358 }
359
360 #ifdef CONFIG_HIGHMEM
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 static inline void permanent_kmaps_init(pgd_t *pgd_base)
441 {
442 }
443 static inline void set_highmem_pages_init(void)
444 {
445 }
446 #endif /* CONFIG_HIGHMEM */
447
448 void __init native_pagetable_setup_start(pgd_t *base)
449 {
450         unsigned long pfn, va;
451         pgd_t *pgd;
452         pud_t *pud;
453         pmd_t *pmd;
454         pte_t *pte;
455
456         /*
457          * Remove any mappings which extend past the end of physical
458          * memory from the boot time page table:
459          */
460         for (pfn = max_low_pfn + 1; pfn < 1<<(32-PAGE_SHIFT); pfn++) {
461                 va = PAGE_OFFSET + (pfn<<PAGE_SHIFT);
462                 pgd = base + pgd_index(va);
463                 if (!pgd_present(*pgd))
464                         break;
465
466                 pud = pud_offset(pgd, va);
467                 pmd = pmd_offset(pud, va);
468                 if (!pmd_present(*pmd))
469                         break;
470
471                 pte = pte_offset_kernel(pmd, va);
472                 if (!pte_present(*pte))
473                         break;
474
475                 pte_clear(NULL, va, pte);
476         }
477         paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT);
478 }
479
480 void __init native_pagetable_setup_done(pgd_t *base)
481 {
482 }
483
484 /*
485  * Build a proper pagetable for the kernel mappings.  Up until this
486  * point, we've been running on some set of pagetables constructed by
487  * the boot process.
488  *
489  * If we're booting on native hardware, this will be a pagetable
490  * constructed in arch/x86/kernel/head_32.S.  The root of the
491  * pagetable will be swapper_pg_dir.
492  *
493  * If we're booting paravirtualized under a hypervisor, then there are
494  * more options: we may already be running PAE, and the pagetable may
495  * or may not be based in swapper_pg_dir.  In any case,
496  * paravirt_pagetable_setup_start() will set up swapper_pg_dir
497  * appropriately for the rest of the initialization to work.
498  *
499  * In general, pagetable_init() assumes that the pagetable may already
500  * be partially populated, and so it avoids stomping on any existing
501  * mappings.
502  */
503 static void __init early_ioremap_page_table_range_init(pgd_t *pgd_base)
504 {
505         unsigned long vaddr, end;
506
507         /*
508          * Fixed mappings, only the page table structure has to be
509          * created - mappings will be set by set_fixmap():
510          */
511         early_ioremap_clear();
512         vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
513         end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
514         page_table_range_init(vaddr, end, pgd_base);
515         early_ioremap_reset();
516 }
517
518 static void __init pagetable_init(void)
519 {
520         pgd_t *pgd_base = swapper_pg_dir;
521
522         permanent_kmaps_init(pgd_base);
523 }
524
525 #ifdef CONFIG_ACPI_SLEEP
526 /*
527  * ACPI suspend needs this for resume, because things like the intel-agp
528  * driver might have split up a kernel 4MB mapping.
529  */
530 char swsusp_pg_dir[PAGE_SIZE]
531         __attribute__ ((aligned(PAGE_SIZE)));
532
533 static inline void save_pg_dir(void)
534 {
535         memcpy(swsusp_pg_dir, swapper_pg_dir, PAGE_SIZE);
536 }
537 #else /* !CONFIG_ACPI_SLEEP */
538 static inline void save_pg_dir(void)
539 {
540 }
541 #endif /* !CONFIG_ACPI_SLEEP */
542
543 void zap_low_mappings(void)
544 {
545         int i;
546
547         /*
548          * Zap initial low-memory mappings.
549          *
550          * Note that "pgd_clear()" doesn't do it for
551          * us, because pgd_clear() is a no-op on i386.
552          */
553         for (i = 0; i < KERNEL_PGD_BOUNDARY; i++) {
554 #ifdef CONFIG_X86_PAE
555                 set_pgd(swapper_pg_dir+i, __pgd(1 + __pa(empty_zero_page)));
556 #else
557                 set_pgd(swapper_pg_dir+i, __pgd(0));
558 #endif
559         }
560         flush_tlb_all();
561 }
562
563 int nx_enabled;
564
565 pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL | _PAGE_IOMAP);
566 EXPORT_SYMBOL_GPL(__supported_pte_mask);
567
568 #ifdef CONFIG_X86_PAE
569
570 static int disable_nx __initdata;
571
572 /*
573  * noexec = on|off
574  *
575  * Control non executable mappings.
576  *
577  * on      Enable
578  * off     Disable
579  */
580 static int __init noexec_setup(char *str)
581 {
582         if (!str || !strcmp(str, "on")) {
583                 if (cpu_has_nx) {
584                         __supported_pte_mask |= _PAGE_NX;
585                         disable_nx = 0;
586                 }
587         } else {
588                 if (!strcmp(str, "off")) {
589                         disable_nx = 1;
590                         __supported_pte_mask &= ~_PAGE_NX;
591                 } else {
592                         return -EINVAL;
593                 }
594         }
595
596         return 0;
597 }
598 early_param("noexec", noexec_setup);
599
600 static void __init set_nx(void)
601 {
602         unsigned int v[4], l, h;
603
604         if (cpu_has_pae && (cpuid_eax(0x80000000) > 0x80000001)) {
605                 cpuid(0x80000001, &v[0], &v[1], &v[2], &v[3]);
606
607                 if ((v[3] & (1 << 20)) && !disable_nx) {
608                         rdmsr(MSR_EFER, l, h);
609                         l |= EFER_NX;
610                         wrmsr(MSR_EFER, l, h);
611                         nx_enabled = 1;
612                         __supported_pte_mask |= _PAGE_NX;
613                 }
614         }
615 }
616 #endif
617
618 /* user-defined highmem size */
619 static unsigned int highmem_pages = -1;
620
621 /*
622  * highmem=size forces highmem to be exactly 'size' bytes.
623  * This works even on boxes that have no highmem otherwise.
624  * This also works to reduce highmem size on bigger boxes.
625  */
626 static int __init parse_highmem(char *arg)
627 {
628         if (!arg)
629                 return -EINVAL;
630
631         highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT;
632         return 0;
633 }
634 early_param("highmem", parse_highmem);
635
636 /*
637  * Determine low and high memory ranges:
638  */
639 void __init find_low_pfn_range(void)
640 {
641         /* it could update max_pfn */
642
643         /* max_low_pfn is 0, we already have early_res support */
644
645         max_low_pfn = max_pfn;
646         if (max_low_pfn > MAXMEM_PFN) {
647                 if (highmem_pages == -1)
648                         highmem_pages = max_pfn - MAXMEM_PFN;
649                 if (highmem_pages + MAXMEM_PFN < max_pfn)
650                         max_pfn = MAXMEM_PFN + highmem_pages;
651                 if (highmem_pages + MAXMEM_PFN > max_pfn) {
652                         printk(KERN_WARNING "only %luMB highmem pages "
653                                 "available, ignoring highmem size of %uMB.\n",
654                                 pages_to_mb(max_pfn - MAXMEM_PFN),
655                                 pages_to_mb(highmem_pages));
656                         highmem_pages = 0;
657                 }
658                 max_low_pfn = MAXMEM_PFN;
659 #ifndef CONFIG_HIGHMEM
660                 /* Maximum memory usable is what is directly addressable */
661                 printk(KERN_WARNING "Warning only %ldMB will be used.\n",
662                                         MAXMEM>>20);
663                 if (max_pfn > MAX_NONPAE_PFN)
664                         printk(KERN_WARNING
665                                  "Use a HIGHMEM64G enabled kernel.\n");
666                 else
667                         printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");
668                 max_pfn = MAXMEM_PFN;
669 #else /* !CONFIG_HIGHMEM */
670 #ifndef CONFIG_HIGHMEM64G
671                 if (max_pfn > MAX_NONPAE_PFN) {
672                         max_pfn = MAX_NONPAE_PFN;
673                         printk(KERN_WARNING "Warning only 4GB will be used."
674                                 "Use a HIGHMEM64G enabled kernel.\n");
675                 }
676 #endif /* !CONFIG_HIGHMEM64G */
677 #endif /* !CONFIG_HIGHMEM */
678         } else {
679                 if (highmem_pages == -1)
680                         highmem_pages = 0;
681 #ifdef CONFIG_HIGHMEM
682                 if (highmem_pages >= max_pfn) {
683                         printk(KERN_ERR "highmem size specified (%uMB) is "
684                                 "bigger than pages available (%luMB)!.\n",
685                                 pages_to_mb(highmem_pages),
686                                 pages_to_mb(max_pfn));
687                         highmem_pages = 0;
688                 }
689                 if (highmem_pages) {
690                         if (max_low_pfn - highmem_pages <
691                             64*1024*1024/PAGE_SIZE){
692                                 printk(KERN_ERR "highmem size %uMB results in "
693                                 "smaller than 64MB lowmem, ignoring it.\n"
694                                         , pages_to_mb(highmem_pages));
695                                 highmem_pages = 0;
696                         }
697                         max_low_pfn -= highmem_pages;
698                 }
699 #else
700                 if (highmem_pages)
701                         printk(KERN_ERR "ignoring highmem size on non-highmem"
702                                         " kernel!\n");
703 #endif
704         }
705 }
706
707 #ifndef CONFIG_NEED_MULTIPLE_NODES
708 void __init initmem_init(unsigned long start_pfn,
709                                   unsigned long end_pfn)
710 {
711 #ifdef CONFIG_HIGHMEM
712         highstart_pfn = highend_pfn = max_pfn;
713         if (max_pfn > max_low_pfn)
714                 highstart_pfn = max_low_pfn;
715         memory_present(0, 0, highend_pfn);
716         e820_register_active_regions(0, 0, highend_pfn);
717         printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
718                 pages_to_mb(highend_pfn - highstart_pfn));
719         num_physpages = highend_pfn;
720         high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1;
721 #else
722         memory_present(0, 0, max_low_pfn);
723         e820_register_active_regions(0, 0, max_low_pfn);
724         num_physpages = max_low_pfn;
725         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1;
726 #endif
727 #ifdef CONFIG_FLATMEM
728         max_mapnr = num_physpages;
729 #endif
730         printk(KERN_NOTICE "%ldMB LOWMEM available.\n",
731                         pages_to_mb(max_low_pfn));
732
733         setup_bootmem_allocator();
734 }
735 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
736
737 static void __init zone_sizes_init(void)
738 {
739         unsigned long max_zone_pfns[MAX_NR_ZONES];
740         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
741         max_zone_pfns[ZONE_DMA] =
742                 virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
743         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
744 #ifdef CONFIG_HIGHMEM
745         max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
746 #endif
747
748         free_area_init_nodes(max_zone_pfns);
749 }
750
751 void __init setup_bootmem_allocator(void)
752 {
753         int i;
754         unsigned long bootmap_size, bootmap;
755         /*
756          * Initialize the boot-time allocator (with low memory only):
757          */
758         bootmap_size = bootmem_bootmap_pages(max_low_pfn)<<PAGE_SHIFT;
759         bootmap = find_e820_area(min_low_pfn<<PAGE_SHIFT,
760                                  max_pfn_mapped<<PAGE_SHIFT, bootmap_size,
761                                  PAGE_SIZE);
762         if (bootmap == -1L)
763                 panic("Cannot find bootmem map of size %ld\n", bootmap_size);
764         reserve_early(bootmap, bootmap + bootmap_size, "BOOTMAP");
765
766         /* don't touch min_low_pfn */
767         bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap >> PAGE_SHIFT,
768                                          min_low_pfn, max_low_pfn);
769         printk(KERN_INFO "  mapped low ram: 0 - %08lx\n",
770                  max_pfn_mapped<<PAGE_SHIFT);
771         printk(KERN_INFO "  low ram: %08lx - %08lx\n",
772                  min_low_pfn<<PAGE_SHIFT, max_low_pfn<<PAGE_SHIFT);
773         printk(KERN_INFO "  bootmap %08lx - %08lx\n",
774                  bootmap, bootmap + bootmap_size);
775         for_each_online_node(i)
776                 free_bootmem_with_active_regions(i, max_low_pfn);
777         early_res_to_bootmem(0, max_low_pfn<<PAGE_SHIFT);
778
779         after_init_bootmem = 1;
780 }
781
782 static void __init find_early_table_space(unsigned long end, int use_pse)
783 {
784         unsigned long puds, pmds, ptes, tables, start;
785
786         puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
787         tables = PAGE_ALIGN(puds * sizeof(pud_t));
788
789         pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
790         tables += PAGE_ALIGN(pmds * sizeof(pmd_t));
791
792         if (use_pse) {
793                 unsigned long extra;
794
795                 extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT);
796                 extra += PMD_SIZE;
797                 ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT;
798         } else
799                 ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT;
800
801         tables += PAGE_ALIGN(ptes * sizeof(pte_t));
802
803         /* for fixmap */
804         tables += PAGE_SIZE * 2;
805
806         /*
807          * RED-PEN putting page tables only on node 0 could
808          * cause a hotspot and fill up ZONE_DMA. The page tables
809          * need roughly 0.5KB per GB.
810          */
811         start = 0x7000;
812         table_start = find_e820_area(start, max_pfn_mapped<<PAGE_SHIFT,
813                                         tables, PAGE_SIZE);
814         if (table_start == -1UL)
815                 panic("Cannot find space for the kernel page tables");
816
817         table_start >>= PAGE_SHIFT;
818         table_end = table_start;
819         table_top = table_start + (tables>>PAGE_SHIFT);
820
821         printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n",
822                 end, table_start << PAGE_SHIFT,
823                 (table_start << PAGE_SHIFT) + tables);
824 }
825
826 unsigned long __init_refok init_memory_mapping(unsigned long start,
827                                                 unsigned long end)
828 {
829         pgd_t *pgd_base = swapper_pg_dir;
830         unsigned long start_pfn, end_pfn;
831         unsigned long big_page_start;
832 #ifdef CONFIG_DEBUG_PAGEALLOC
833         /*
834          * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
835          * This will simplify cpa(), which otherwise needs to support splitting
836          * large pages into small in interrupt context, etc.
837          */
838         int use_pse = 0;
839 #else
840         int use_pse = cpu_has_pse;
841 #endif
842
843         /*
844          * Find space for the kernel direct mapping tables.
845          */
846         if (!after_init_bootmem)
847                 find_early_table_space(end, use_pse);
848
849 #ifdef CONFIG_X86_PAE
850         set_nx();
851         if (nx_enabled)
852                 printk(KERN_INFO "NX (Execute Disable) protection: active\n");
853 #endif
854
855         /* Enable PSE if available */
856         if (cpu_has_pse)
857                 set_in_cr4(X86_CR4_PSE);
858
859         /* Enable PGE if available */
860         if (cpu_has_pge) {
861                 set_in_cr4(X86_CR4_PGE);
862                 __supported_pte_mask |= _PAGE_GLOBAL;
863         }
864
865         /*
866          * Don't use a large page for the first 2/4MB of memory
867          * because there are often fixed size MTRRs in there
868          * and overlapping MTRRs into large pages can cause
869          * slowdowns.
870          */
871         big_page_start = PMD_SIZE;
872
873         if (start < big_page_start) {
874                 start_pfn = start >> PAGE_SHIFT;
875                 end_pfn = min(big_page_start>>PAGE_SHIFT, end>>PAGE_SHIFT);
876         } else {
877                 /* head is not big page alignment ? */
878                 start_pfn = start >> PAGE_SHIFT;
879                 end_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT)
880                                  << (PMD_SHIFT - PAGE_SHIFT);
881         }
882         if (start_pfn < end_pfn)
883                 kernel_physical_mapping_init(pgd_base, start_pfn, end_pfn, 0);
884
885         /* big page range */
886         start_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT)
887                          << (PMD_SHIFT - PAGE_SHIFT);
888         if (start_pfn < (big_page_start >> PAGE_SHIFT))
889                 start_pfn =  big_page_start >> PAGE_SHIFT;
890         end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
891         if (start_pfn < end_pfn)
892                 kernel_physical_mapping_init(pgd_base, start_pfn, end_pfn,
893                                              use_pse);
894
895         /* tail is not big page alignment ? */
896         start_pfn = end_pfn;
897         if (start_pfn > (big_page_start>>PAGE_SHIFT)) {
898                 end_pfn = end >> PAGE_SHIFT;
899                 if (start_pfn < end_pfn)
900                         kernel_physical_mapping_init(pgd_base, start_pfn,
901                                                          end_pfn, 0);
902         }
903
904         early_ioremap_page_table_range_init(pgd_base);
905
906         load_cr3(swapper_pg_dir);
907
908         __flush_tlb_all();
909
910         if (!after_init_bootmem)
911                 reserve_early(table_start << PAGE_SHIFT,
912                                  table_end << PAGE_SHIFT, "PGTABLE");
913
914         if (!after_init_bootmem)
915                 early_memtest(start, end);
916
917         return end >> PAGE_SHIFT;
918 }
919
920
921 /*
922  * paging_init() sets up the page tables - note that the first 8MB are
923  * already mapped by head.S.
924  *
925  * This routines also unmaps the page at virtual kernel address 0, so
926  * that we can trap those pesky NULL-reference errors in the kernel.
927  */
928 void __init paging_init(void)
929 {
930         pagetable_init();
931
932         __flush_tlb_all();
933
934         kmap_init();
935
936         /*
937          * NOTE: at this point the bootmem allocator is fully available.
938          */
939         sparse_init();
940         zone_sizes_init();
941 }
942
943 /*
944  * Test if the WP bit works in supervisor mode. It isn't supported on 386's
945  * and also on some strange 486's. All 586+'s are OK. This used to involve
946  * black magic jumps to work around some nasty CPU bugs, but fortunately the
947  * switch to using exceptions got rid of all that.
948  */
949 static void __init test_wp_bit(void)
950 {
951         printk(KERN_INFO
952   "Checking if this processor honours the WP bit even in supervisor mode...");
953
954         /* Any page-aligned address will do, the test is non-destructive */
955         __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_READONLY);
956         boot_cpu_data.wp_works_ok = do_test_wp_bit();
957         clear_fixmap(FIX_WP_TEST);
958
959         if (!boot_cpu_data.wp_works_ok) {
960                 printk(KERN_CONT "No.\n");
961 #ifdef CONFIG_X86_WP_WORKS_OK
962                 panic(
963   "This kernel doesn't support CPU's with broken WP. Recompile it for a 386!");
964 #endif
965         } else {
966                 printk(KERN_CONT "Ok.\n");
967         }
968 }
969
970 static struct kcore_list kcore_mem, kcore_vmalloc;
971
972 void __init mem_init(void)
973 {
974         int codesize, reservedpages, datasize, initsize;
975         int tmp;
976
977         pci_iommu_alloc();
978
979 #ifdef CONFIG_FLATMEM
980         BUG_ON(!mem_map);
981 #endif
982         /* this will put all low memory onto the freelists */
983         totalram_pages += free_all_bootmem();
984
985         reservedpages = 0;
986         for (tmp = 0; tmp < max_low_pfn; tmp++)
987                 /*
988                  * Only count reserved RAM pages:
989                  */
990                 if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp)))
991                         reservedpages++;
992
993         set_highmem_pages_init();
994
995         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
996         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
997         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
998
999         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
1000         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
1001                    VMALLOC_END-VMALLOC_START);
1002
1003         printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
1004                         "%dk reserved, %dk data, %dk init, %ldk highmem)\n",
1005                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
1006                 num_physpages << (PAGE_SHIFT-10),
1007                 codesize >> 10,
1008                 reservedpages << (PAGE_SHIFT-10),
1009                 datasize >> 10,
1010                 initsize >> 10,
1011                 (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10))
1012                );
1013
1014         printk(KERN_INFO "virtual kernel memory layout:\n"
1015                 "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
1016 #ifdef CONFIG_HIGHMEM
1017                 "    pkmap   : 0x%08lx - 0x%08lx   (%4ld kB)\n"
1018 #endif
1019                 "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
1020                 "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
1021                 "      .init : 0x%08lx - 0x%08lx   (%4ld kB)\n"
1022                 "      .data : 0x%08lx - 0x%08lx   (%4ld kB)\n"
1023                 "      .text : 0x%08lx - 0x%08lx   (%4ld kB)\n",
1024                 FIXADDR_START, FIXADDR_TOP,
1025                 (FIXADDR_TOP - FIXADDR_START) >> 10,
1026
1027 #ifdef CONFIG_HIGHMEM
1028                 PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
1029                 (LAST_PKMAP*PAGE_SIZE) >> 10,
1030 #endif
1031
1032                 VMALLOC_START, VMALLOC_END,
1033                 (VMALLOC_END - VMALLOC_START) >> 20,
1034
1035                 (unsigned long)__va(0), (unsigned long)high_memory,
1036                 ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
1037
1038                 (unsigned long)&__init_begin, (unsigned long)&__init_end,
1039                 ((unsigned long)&__init_end -
1040                  (unsigned long)&__init_begin) >> 10,
1041
1042                 (unsigned long)&_etext, (unsigned long)&_edata,
1043                 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
1044
1045                 (unsigned long)&_text, (unsigned long)&_etext,
1046                 ((unsigned long)&_etext - (unsigned long)&_text) >> 10);
1047
1048         /*
1049          * Check boundaries twice: Some fundamental inconsistencies can
1050          * be detected at build time already.
1051          */
1052 #define __FIXADDR_TOP (-PAGE_SIZE)
1053 #ifdef CONFIG_HIGHMEM
1054         BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE  > FIXADDR_START);
1055         BUILD_BUG_ON(VMALLOC_END                        > PKMAP_BASE);
1056 #endif
1057 #define high_memory (-128UL << 20)
1058         BUILD_BUG_ON(VMALLOC_START                      >= VMALLOC_END);
1059 #undef high_memory
1060 #undef __FIXADDR_TOP
1061
1062 #ifdef CONFIG_HIGHMEM
1063         BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE        > FIXADDR_START);
1064         BUG_ON(VMALLOC_END                              > PKMAP_BASE);
1065 #endif
1066         BUG_ON(VMALLOC_START                            >= VMALLOC_END);
1067         BUG_ON((unsigned long)high_memory               > VMALLOC_START);
1068
1069         if (boot_cpu_data.wp_works_ok < 0)
1070                 test_wp_bit();
1071
1072         save_pg_dir();
1073         zap_low_mappings();
1074 }
1075
1076 #ifdef CONFIG_MEMORY_HOTPLUG
1077 int arch_add_memory(int nid, u64 start, u64 size)
1078 {
1079         struct pglist_data *pgdata = NODE_DATA(nid);
1080         struct zone *zone = pgdata->node_zones + ZONE_HIGHMEM;
1081         unsigned long start_pfn = start >> PAGE_SHIFT;
1082         unsigned long nr_pages = size >> PAGE_SHIFT;
1083
1084         return __add_pages(nid, zone, start_pfn, nr_pages);
1085 }
1086 #endif
1087
1088 /*
1089  * This function cannot be __init, since exceptions don't work in that
1090  * section.  Put this after the callers, so that it cannot be inlined.
1091  */
1092 static noinline int do_test_wp_bit(void)
1093 {
1094         char tmp_reg;
1095         int flag;
1096
1097         __asm__ __volatile__(
1098                 "       movb %0, %1     \n"
1099                 "1:     movb %1, %0     \n"
1100                 "       xorl %2, %2     \n"
1101                 "2:                     \n"
1102                 _ASM_EXTABLE(1b,2b)
1103                 :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)),
1104                  "=q" (tmp_reg),
1105                  "=r" (flag)
1106                 :"2" (1)
1107                 :"memory");
1108
1109         return flag;
1110 }
1111
1112 #ifdef CONFIG_DEBUG_RODATA
1113 const int rodata_test_data = 0xC3;
1114 EXPORT_SYMBOL_GPL(rodata_test_data);
1115
1116 void mark_rodata_ro(void)
1117 {
1118         unsigned long start = PFN_ALIGN(_text);
1119         unsigned long size = PFN_ALIGN(_etext) - start;
1120
1121 #ifndef CONFIG_DYNAMIC_FTRACE
1122         /* Dynamic tracing modifies the kernel text section */
1123         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
1124         printk(KERN_INFO "Write protecting the kernel text: %luk\n",
1125                 size >> 10);
1126
1127 #ifdef CONFIG_CPA_DEBUG
1128         printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n",
1129                 start, start+size);
1130         set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT);
1131
1132         printk(KERN_INFO "Testing CPA: write protecting again\n");
1133         set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT);
1134 #endif
1135 #endif /* CONFIG_DYNAMIC_FTRACE */
1136
1137         start += size;
1138         size = (unsigned long)__end_rodata - start;
1139         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
1140         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
1141                 size >> 10);
1142         rodata_test();
1143
1144 #ifdef CONFIG_CPA_DEBUG
1145         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size);
1146         set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
1147
1148         printk(KERN_INFO "Testing CPA: write protecting again\n");
1149         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
1150 #endif
1151 }
1152 #endif
1153
1154 void free_init_pages(char *what, unsigned long begin, unsigned long end)
1155 {
1156 #ifdef CONFIG_DEBUG_PAGEALLOC
1157         /*
1158          * If debugging page accesses then do not free this memory but
1159          * mark them not present - any buggy init-section access will
1160          * create a kernel page fault:
1161          */
1162         printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
1163                 begin, PAGE_ALIGN(end));
1164         set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
1165 #else
1166         unsigned long addr;
1167
1168         /*
1169          * We just marked the kernel text read only above, now that
1170          * we are going to free part of that, we need to make that
1171          * writeable first.
1172          */
1173         set_memory_rw(begin, (end - begin) >> PAGE_SHIFT);
1174
1175         for (addr = begin; addr < end; addr += PAGE_SIZE) {
1176                 ClearPageReserved(virt_to_page(addr));
1177                 init_page_count(virt_to_page(addr));
1178                 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
1179                 free_page(addr);
1180                 totalram_pages++;
1181         }
1182         printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
1183 #endif
1184 }
1185
1186 void free_initmem(void)
1187 {
1188         free_init_pages("unused kernel memory",
1189                         (unsigned long)(&__init_begin),
1190                         (unsigned long)(&__init_end));
1191 }
1192
1193 #ifdef CONFIG_BLK_DEV_INITRD
1194 void free_initrd_mem(unsigned long start, unsigned long end)
1195 {
1196         free_init_pages("initrd memory", start, end);
1197 }
1198 #endif
1199
1200 int __init reserve_bootmem_generic(unsigned long phys, unsigned long len,
1201                                    int flags)
1202 {
1203         return reserve_bootmem(phys, len, flags);
1204 }