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