Merge branch 'x86-olpc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[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/memblock.h>
29 #include <linux/proc_fs.h>
30 #include <linux/memory_hotplug.h>
31 #include <linux/initrd.h>
32 #include <linux/cpumask.h>
33 #include <linux/gfp.h>
34
35 #include <asm/asm.h>
36 #include <asm/bios_ebda.h>
37 #include <asm/processor.h>
38 #include <asm/system.h>
39 #include <asm/uaccess.h>
40 #include <asm/pgtable.h>
41 #include <asm/dma.h>
42 #include <asm/fixmap.h>
43 #include <asm/e820.h>
44 #include <asm/apic.h>
45 #include <asm/bugs.h>
46 #include <asm/tlb.h>
47 #include <asm/tlbflush.h>
48 #include <asm/olpc_ofw.h>
49 #include <asm/pgalloc.h>
50 #include <asm/sections.h>
51 #include <asm/paravirt.h>
52 #include <asm/setup.h>
53 #include <asm/cacheflush.h>
54 #include <asm/page_types.h>
55 #include <asm/init.h>
56
57 unsigned long highstart_pfn, highend_pfn;
58
59 static noinline int do_test_wp_bit(void);
60
61 bool __read_mostly __vmalloc_start_set = false;
62
63 static __init void *alloc_low_page(void)
64 {
65         unsigned long pfn = e820_table_end++;
66         void *adr;
67
68         if (pfn >= e820_table_top)
69                 panic("alloc_low_page: ran out of memory");
70
71         adr = __va(pfn * PAGE_SIZE);
72         clear_page(adr);
73         return adr;
74 }
75
76 /*
77  * Creates a middle page table and puts a pointer to it in the
78  * given global directory entry. This only returns the gd entry
79  * in non-PAE compilation mode, since the middle layer is folded.
80  */
81 static pmd_t * __init one_md_table_init(pgd_t *pgd)
82 {
83         pud_t *pud;
84         pmd_t *pmd_table;
85
86 #ifdef CONFIG_X86_PAE
87         if (!(pgd_val(*pgd) & _PAGE_PRESENT)) {
88                 if (after_bootmem)
89                         pmd_table = (pmd_t *)alloc_bootmem_pages(PAGE_SIZE);
90                 else
91                         pmd_table = (pmd_t *)alloc_low_page();
92                 paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT);
93                 set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
94                 pud = pud_offset(pgd, 0);
95                 BUG_ON(pmd_table != pmd_offset(pud, 0));
96
97                 return pmd_table;
98         }
99 #endif
100         pud = pud_offset(pgd, 0);
101         pmd_table = pmd_offset(pud, 0);
102
103         return pmd_table;
104 }
105
106 /*
107  * Create a page table and place a pointer to it in a middle page
108  * directory entry:
109  */
110 static pte_t * __init one_page_table_init(pmd_t *pmd)
111 {
112         if (!(pmd_val(*pmd) & _PAGE_PRESENT)) {
113                 pte_t *page_table = NULL;
114
115                 if (after_bootmem) {
116 #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KMEMCHECK)
117                         page_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);
118 #endif
119                         if (!page_table)
120                                 page_table =
121                                 (pte_t *)alloc_bootmem_pages(PAGE_SIZE);
122                 } else
123                         page_table = (pte_t *)alloc_low_page();
124
125                 paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT);
126                 set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE));
127                 BUG_ON(page_table != pte_offset_kernel(pmd, 0));
128         }
129
130         return pte_offset_kernel(pmd, 0);
131 }
132
133 pmd_t * __init populate_extra_pmd(unsigned long vaddr)
134 {
135         int pgd_idx = pgd_index(vaddr);
136         int pmd_idx = pmd_index(vaddr);
137
138         return one_md_table_init(swapper_pg_dir + pgd_idx) + pmd_idx;
139 }
140
141 pte_t * __init populate_extra_pte(unsigned long vaddr)
142 {
143         int pte_idx = pte_index(vaddr);
144         pmd_t *pmd;
145
146         pmd = populate_extra_pmd(vaddr);
147         return one_page_table_init(pmd) + pte_idx;
148 }
149
150 static pte_t *__init page_table_kmap_check(pte_t *pte, pmd_t *pmd,
151                                            unsigned long vaddr, pte_t *lastpte)
152 {
153 #ifdef CONFIG_HIGHMEM
154         /*
155          * Something (early fixmap) may already have put a pte
156          * page here, which causes the page table allocation
157          * to become nonlinear. Attempt to fix it, and if it
158          * is still nonlinear then we have to bug.
159          */
160         int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT;
161         int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT;
162
163         if (pmd_idx_kmap_begin != pmd_idx_kmap_end
164             && (vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin
165             && (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end
166             && ((__pa(pte) >> PAGE_SHIFT) < e820_table_start
167                 || (__pa(pte) >> PAGE_SHIFT) >= e820_table_end)) {
168                 pte_t *newpte;
169                 int i;
170
171                 BUG_ON(after_bootmem);
172                 newpte = alloc_low_page();
173                 for (i = 0; i < PTRS_PER_PTE; i++)
174                         set_pte(newpte + i, pte[i]);
175
176                 paravirt_alloc_pte(&init_mm, __pa(newpte) >> PAGE_SHIFT);
177                 set_pmd(pmd, __pmd(__pa(newpte)|_PAGE_TABLE));
178                 BUG_ON(newpte != pte_offset_kernel(pmd, 0));
179                 __flush_tlb_all();
180
181                 paravirt_release_pte(__pa(pte) >> PAGE_SHIFT);
182                 pte = newpte;
183         }
184         BUG_ON(vaddr < fix_to_virt(FIX_KMAP_BEGIN - 1)
185                && vaddr > fix_to_virt(FIX_KMAP_END)
186                && lastpte && lastpte + PTRS_PER_PTE != pte);
187 #endif
188         return pte;
189 }
190
191 /*
192  * This function initializes a certain range of kernel virtual memory
193  * with new bootmem page tables, everywhere page tables are missing in
194  * the given range.
195  *
196  * NOTE: The pagetables are allocated contiguous on the physical space
197  * so we can cache the place of the first one and move around without
198  * checking the pgd every time.
199  */
200 static void __init
201 page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base)
202 {
203         int pgd_idx, pmd_idx;
204         unsigned long vaddr;
205         pgd_t *pgd;
206         pmd_t *pmd;
207         pte_t *pte = NULL;
208
209         vaddr = start;
210         pgd_idx = pgd_index(vaddr);
211         pmd_idx = pmd_index(vaddr);
212         pgd = pgd_base + pgd_idx;
213
214         for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
215                 pmd = one_md_table_init(pgd);
216                 pmd = pmd + pmd_index(vaddr);
217                 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);
218                                                         pmd++, pmd_idx++) {
219                         pte = page_table_kmap_check(one_page_table_init(pmd),
220                                                     pmd, vaddr, pte);
221
222                         vaddr += PMD_SIZE;
223                 }
224                 pmd_idx = 0;
225         }
226 }
227
228 static inline int is_kernel_text(unsigned long addr)
229 {
230         if (addr >= (unsigned long)_text && addr <= (unsigned long)__init_end)
231                 return 1;
232         return 0;
233 }
234
235 /*
236  * This maps the physical memory to kernel virtual address space, a total
237  * of max_low_pfn pages, by creating page tables starting from address
238  * PAGE_OFFSET:
239  */
240 unsigned long __init
241 kernel_physical_mapping_init(unsigned long start,
242                              unsigned long end,
243                              unsigned long page_size_mask)
244 {
245         int use_pse = page_size_mask == (1<<PG_LEVEL_2M);
246         unsigned long last_map_addr = end;
247         unsigned long start_pfn, end_pfn;
248         pgd_t *pgd_base = swapper_pg_dir;
249         int pgd_idx, pmd_idx, pte_ofs;
250         unsigned long pfn;
251         pgd_t *pgd;
252         pmd_t *pmd;
253         pte_t *pte;
254         unsigned pages_2m, pages_4k;
255         int mapping_iter;
256
257         start_pfn = start >> PAGE_SHIFT;
258         end_pfn = end >> PAGE_SHIFT;
259
260         /*
261          * First iteration will setup identity mapping using large/small pages
262          * based on use_pse, with other attributes same as set by
263          * the early code in head_32.S
264          *
265          * Second iteration will setup the appropriate attributes (NX, GLOBAL..)
266          * as desired for the kernel identity mapping.
267          *
268          * This two pass mechanism conforms to the TLB app note which says:
269          *
270          *     "Software should not write to a paging-structure entry in a way
271          *      that would change, for any linear address, both the page size
272          *      and either the page frame or attributes."
273          */
274         mapping_iter = 1;
275
276         if (!cpu_has_pse)
277                 use_pse = 0;
278
279 repeat:
280         pages_2m = pages_4k = 0;
281         pfn = start_pfn;
282         pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
283         pgd = pgd_base + pgd_idx;
284         for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) {
285                 pmd = one_md_table_init(pgd);
286
287                 if (pfn >= end_pfn)
288                         continue;
289 #ifdef CONFIG_X86_PAE
290                 pmd_idx = pmd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
291                 pmd += pmd_idx;
292 #else
293                 pmd_idx = 0;
294 #endif
295                 for (; pmd_idx < PTRS_PER_PMD && pfn < end_pfn;
296                      pmd++, pmd_idx++) {
297                         unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET;
298
299                         /*
300                          * Map with big pages if possible, otherwise
301                          * create normal page tables:
302                          */
303                         if (use_pse) {
304                                 unsigned int addr2;
305                                 pgprot_t prot = PAGE_KERNEL_LARGE;
306                                 /*
307                                  * first pass will use the same initial
308                                  * identity mapping attribute + _PAGE_PSE.
309                                  */
310                                 pgprot_t init_prot =
311                                         __pgprot(PTE_IDENT_ATTR |
312                                                  _PAGE_PSE);
313
314                                 addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE +
315                                         PAGE_OFFSET + PAGE_SIZE-1;
316
317                                 if (is_kernel_text(addr) ||
318                                     is_kernel_text(addr2))
319                                         prot = PAGE_KERNEL_LARGE_EXEC;
320
321                                 pages_2m++;
322                                 if (mapping_iter == 1)
323                                         set_pmd(pmd, pfn_pmd(pfn, init_prot));
324                                 else
325                                         set_pmd(pmd, pfn_pmd(pfn, prot));
326
327                                 pfn += PTRS_PER_PTE;
328                                 continue;
329                         }
330                         pte = one_page_table_init(pmd);
331
332                         pte_ofs = pte_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
333                         pte += pte_ofs;
334                         for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn;
335                              pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) {
336                                 pgprot_t prot = PAGE_KERNEL;
337                                 /*
338                                  * first pass will use the same initial
339                                  * identity mapping attribute.
340                                  */
341                                 pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR);
342
343                                 if (is_kernel_text(addr))
344                                         prot = PAGE_KERNEL_EXEC;
345
346                                 pages_4k++;
347                                 if (mapping_iter == 1) {
348                                         set_pte(pte, pfn_pte(pfn, init_prot));
349                                         last_map_addr = (pfn << PAGE_SHIFT) + PAGE_SIZE;
350                                 } else
351                                         set_pte(pte, pfn_pte(pfn, prot));
352                         }
353                 }
354         }
355         if (mapping_iter == 1) {
356                 /*
357                  * update direct mapping page count only in the first
358                  * iteration.
359                  */
360                 update_page_count(PG_LEVEL_2M, pages_2m);
361                 update_page_count(PG_LEVEL_4K, pages_4k);
362
363                 /*
364                  * local global flush tlb, which will flush the previous
365                  * mappings present in both small and large page TLB's.
366                  */
367                 __flush_tlb_all();
368
369                 /*
370                  * Second iteration will set the actual desired PTE attributes.
371                  */
372                 mapping_iter = 2;
373                 goto repeat;
374         }
375         return last_map_addr;
376 }
377
378 pte_t *kmap_pte;
379 pgprot_t kmap_prot;
380
381 static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr)
382 {
383         return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
384                         vaddr), vaddr), vaddr);
385 }
386
387 static void __init kmap_init(void)
388 {
389         unsigned long kmap_vstart;
390
391         /*
392          * Cache the first kmap pte:
393          */
394         kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
395         kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
396
397         kmap_prot = PAGE_KERNEL;
398 }
399
400 #ifdef CONFIG_HIGHMEM
401 static void __init permanent_kmaps_init(pgd_t *pgd_base)
402 {
403         unsigned long vaddr;
404         pgd_t *pgd;
405         pud_t *pud;
406         pmd_t *pmd;
407         pte_t *pte;
408
409         vaddr = PKMAP_BASE;
410         page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
411
412         pgd = swapper_pg_dir + pgd_index(vaddr);
413         pud = pud_offset(pgd, vaddr);
414         pmd = pmd_offset(pud, vaddr);
415         pte = pte_offset_kernel(pmd, vaddr);
416         pkmap_page_table = pte;
417 }
418
419 static void __init add_one_highpage_init(struct page *page)
420 {
421         ClearPageReserved(page);
422         init_page_count(page);
423         __free_page(page);
424         totalhigh_pages++;
425 }
426
427 void __init add_highpages_with_active_regions(int nid,
428                          unsigned long start_pfn, unsigned long end_pfn)
429 {
430         struct range *range;
431         int nr_range;
432         int i;
433
434         nr_range = __get_free_all_memory_range(&range, nid, start_pfn, end_pfn);
435
436         for (i = 0; i < nr_range; i++) {
437                 struct page *page;
438                 int node_pfn;
439
440                 for (node_pfn = range[i].start; node_pfn < range[i].end;
441                      node_pfn++) {
442                         if (!pfn_valid(node_pfn))
443                                 continue;
444                         page = pfn_to_page(node_pfn);
445                         add_one_highpage_init(page);
446                 }
447         }
448 }
449 #else
450 static inline void permanent_kmaps_init(pgd_t *pgd_base)
451 {
452 }
453 #endif /* CONFIG_HIGHMEM */
454
455 void __init native_pagetable_setup_start(pgd_t *base)
456 {
457         unsigned long pfn, va;
458         pgd_t *pgd;
459         pud_t *pud;
460         pmd_t *pmd;
461         pte_t *pte;
462
463         /*
464          * Remove any mappings which extend past the end of physical
465          * memory from the boot time page table:
466          */
467         for (pfn = max_low_pfn + 1; pfn < 1<<(32-PAGE_SHIFT); pfn++) {
468                 va = PAGE_OFFSET + (pfn<<PAGE_SHIFT);
469                 pgd = base + pgd_index(va);
470                 if (!pgd_present(*pgd))
471                         break;
472
473                 pud = pud_offset(pgd, va);
474                 pmd = pmd_offset(pud, va);
475                 if (!pmd_present(*pmd))
476                         break;
477
478                 pte = pte_offset_kernel(pmd, va);
479                 if (!pte_present(*pte))
480                         break;
481
482                 pte_clear(NULL, va, pte);
483         }
484         paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT);
485 }
486
487 void __init native_pagetable_setup_done(pgd_t *base)
488 {
489 }
490
491 /*
492  * Build a proper pagetable for the kernel mappings.  Up until this
493  * point, we've been running on some set of pagetables constructed by
494  * the boot process.
495  *
496  * If we're booting on native hardware, this will be a pagetable
497  * constructed in arch/x86/kernel/head_32.S.  The root of the
498  * pagetable will be swapper_pg_dir.
499  *
500  * If we're booting paravirtualized under a hypervisor, then there are
501  * more options: we may already be running PAE, and the pagetable may
502  * or may not be based in swapper_pg_dir.  In any case,
503  * paravirt_pagetable_setup_start() will set up swapper_pg_dir
504  * appropriately for the rest of the initialization to work.
505  *
506  * In general, pagetable_init() assumes that the pagetable may already
507  * be partially populated, and so it avoids stomping on any existing
508  * mappings.
509  */
510 void __init early_ioremap_page_table_range_init(void)
511 {
512         pgd_t *pgd_base = swapper_pg_dir;
513         unsigned long vaddr, end;
514
515         /*
516          * Fixed mappings, only the page table structure has to be
517          * created - mappings will be set by set_fixmap():
518          */
519         vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
520         end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
521         page_table_range_init(vaddr, end, pgd_base);
522         early_ioremap_reset();
523 }
524
525 static void __init pagetable_init(void)
526 {
527         pgd_t *pgd_base = swapper_pg_dir;
528
529         permanent_kmaps_init(pgd_base);
530 }
531
532 pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL | _PAGE_IOMAP);
533 EXPORT_SYMBOL_GPL(__supported_pte_mask);
534
535 /* user-defined highmem size */
536 static unsigned int highmem_pages = -1;
537
538 /*
539  * highmem=size forces highmem to be exactly 'size' bytes.
540  * This works even on boxes that have no highmem otherwise.
541  * This also works to reduce highmem size on bigger boxes.
542  */
543 static int __init parse_highmem(char *arg)
544 {
545         if (!arg)
546                 return -EINVAL;
547
548         highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT;
549         return 0;
550 }
551 early_param("highmem", parse_highmem);
552
553 #define MSG_HIGHMEM_TOO_BIG \
554         "highmem size (%luMB) is bigger than pages available (%luMB)!\n"
555
556 #define MSG_LOWMEM_TOO_SMALL \
557         "highmem size (%luMB) results in <64MB lowmem, ignoring it!\n"
558 /*
559  * All of RAM fits into lowmem - but if user wants highmem
560  * artificially via the highmem=x boot parameter then create
561  * it:
562  */
563 void __init lowmem_pfn_init(void)
564 {
565         /* max_low_pfn is 0, we already have early_res support */
566         max_low_pfn = max_pfn;
567
568         if (highmem_pages == -1)
569                 highmem_pages = 0;
570 #ifdef CONFIG_HIGHMEM
571         if (highmem_pages >= max_pfn) {
572                 printk(KERN_ERR MSG_HIGHMEM_TOO_BIG,
573                         pages_to_mb(highmem_pages), pages_to_mb(max_pfn));
574                 highmem_pages = 0;
575         }
576         if (highmem_pages) {
577                 if (max_low_pfn - highmem_pages < 64*1024*1024/PAGE_SIZE) {
578                         printk(KERN_ERR MSG_LOWMEM_TOO_SMALL,
579                                 pages_to_mb(highmem_pages));
580                         highmem_pages = 0;
581                 }
582                 max_low_pfn -= highmem_pages;
583         }
584 #else
585         if (highmem_pages)
586                 printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n");
587 #endif
588 }
589
590 #define MSG_HIGHMEM_TOO_SMALL \
591         "only %luMB highmem pages available, ignoring highmem size of %luMB!\n"
592
593 #define MSG_HIGHMEM_TRIMMED \
594         "Warning: only 4GB will be used. Use a HIGHMEM64G enabled kernel!\n"
595 /*
596  * We have more RAM than fits into lowmem - we try to put it into
597  * highmem, also taking the highmem=x boot parameter into account:
598  */
599 void __init highmem_pfn_init(void)
600 {
601         max_low_pfn = MAXMEM_PFN;
602
603         if (highmem_pages == -1)
604                 highmem_pages = max_pfn - MAXMEM_PFN;
605
606         if (highmem_pages + MAXMEM_PFN < max_pfn)
607                 max_pfn = MAXMEM_PFN + highmem_pages;
608
609         if (highmem_pages + MAXMEM_PFN > max_pfn) {
610                 printk(KERN_WARNING MSG_HIGHMEM_TOO_SMALL,
611                         pages_to_mb(max_pfn - MAXMEM_PFN),
612                         pages_to_mb(highmem_pages));
613                 highmem_pages = 0;
614         }
615 #ifndef CONFIG_HIGHMEM
616         /* Maximum memory usable is what is directly addressable */
617         printk(KERN_WARNING "Warning only %ldMB will be used.\n", MAXMEM>>20);
618         if (max_pfn > MAX_NONPAE_PFN)
619                 printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n");
620         else
621                 printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");
622         max_pfn = MAXMEM_PFN;
623 #else /* !CONFIG_HIGHMEM */
624 #ifndef CONFIG_HIGHMEM64G
625         if (max_pfn > MAX_NONPAE_PFN) {
626                 max_pfn = MAX_NONPAE_PFN;
627                 printk(KERN_WARNING MSG_HIGHMEM_TRIMMED);
628         }
629 #endif /* !CONFIG_HIGHMEM64G */
630 #endif /* !CONFIG_HIGHMEM */
631 }
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         if (max_pfn <= MAXMEM_PFN)
641                 lowmem_pfn_init();
642         else
643                 highmem_pfn_init();
644 }
645
646 #ifndef CONFIG_NEED_MULTIPLE_NODES
647 void __init initmem_init(unsigned long start_pfn, unsigned long end_pfn,
648                                 int acpi, int k8)
649 {
650 #ifdef CONFIG_HIGHMEM
651         highstart_pfn = highend_pfn = max_pfn;
652         if (max_pfn > max_low_pfn)
653                 highstart_pfn = max_low_pfn;
654         memblock_x86_register_active_regions(0, 0, highend_pfn);
655         sparse_memory_present_with_active_regions(0);
656         printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
657                 pages_to_mb(highend_pfn - highstart_pfn));
658         num_physpages = highend_pfn;
659         high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1;
660 #else
661         memblock_x86_register_active_regions(0, 0, max_low_pfn);
662         sparse_memory_present_with_active_regions(0);
663         num_physpages = max_low_pfn;
664         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1;
665 #endif
666 #ifdef CONFIG_FLATMEM
667         max_mapnr = num_physpages;
668 #endif
669         __vmalloc_start_set = true;
670
671         printk(KERN_NOTICE "%ldMB LOWMEM available.\n",
672                         pages_to_mb(max_low_pfn));
673
674         setup_bootmem_allocator();
675 }
676 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
677
678 static void __init zone_sizes_init(void)
679 {
680         unsigned long max_zone_pfns[MAX_NR_ZONES];
681         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
682         max_zone_pfns[ZONE_DMA] =
683                 virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
684         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
685 #ifdef CONFIG_HIGHMEM
686         max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
687 #endif
688
689         free_area_init_nodes(max_zone_pfns);
690 }
691
692 void __init setup_bootmem_allocator(void)
693 {
694         printk(KERN_INFO "  mapped low ram: 0 - %08lx\n",
695                  max_pfn_mapped<<PAGE_SHIFT);
696         printk(KERN_INFO "  low ram: 0 - %08lx\n", max_low_pfn<<PAGE_SHIFT);
697
698         after_bootmem = 1;
699 }
700
701 /*
702  * paging_init() sets up the page tables - note that the first 8MB are
703  * already mapped by head.S.
704  *
705  * This routines also unmaps the page at virtual kernel address 0, so
706  * that we can trap those pesky NULL-reference errors in the kernel.
707  */
708 void __init paging_init(void)
709 {
710         pagetable_init();
711
712         __flush_tlb_all();
713
714         kmap_init();
715
716         /*
717          * NOTE: at this point the bootmem allocator is fully available.
718          */
719         olpc_dt_build_devicetree();
720         sparse_init();
721         zone_sizes_init();
722 }
723
724 /*
725  * Test if the WP bit works in supervisor mode. It isn't supported on 386's
726  * and also on some strange 486's. All 586+'s are OK. This used to involve
727  * black magic jumps to work around some nasty CPU bugs, but fortunately the
728  * switch to using exceptions got rid of all that.
729  */
730 static void __init test_wp_bit(void)
731 {
732         printk(KERN_INFO
733   "Checking if this processor honours the WP bit even in supervisor mode...");
734
735         /* Any page-aligned address will do, the test is non-destructive */
736         __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_READONLY);
737         boot_cpu_data.wp_works_ok = do_test_wp_bit();
738         clear_fixmap(FIX_WP_TEST);
739
740         if (!boot_cpu_data.wp_works_ok) {
741                 printk(KERN_CONT "No.\n");
742 #ifdef CONFIG_X86_WP_WORKS_OK
743                 panic(
744   "This kernel doesn't support CPU's with broken WP. Recompile it for a 386!");
745 #endif
746         } else {
747                 printk(KERN_CONT "Ok.\n");
748         }
749 }
750
751 void __init mem_init(void)
752 {
753         int codesize, reservedpages, datasize, initsize;
754         int tmp;
755
756         pci_iommu_alloc();
757
758 #ifdef CONFIG_FLATMEM
759         BUG_ON(!mem_map);
760 #endif
761         /* this will put all low memory onto the freelists */
762         totalram_pages += free_all_bootmem();
763
764         reservedpages = 0;
765         for (tmp = 0; tmp < max_low_pfn; tmp++)
766                 /*
767                  * Only count reserved RAM pages:
768                  */
769                 if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp)))
770                         reservedpages++;
771
772         set_highmem_pages_init();
773
774         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
775         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
776         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
777
778         printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
779                         "%dk reserved, %dk data, %dk init, %ldk highmem)\n",
780                 nr_free_pages() << (PAGE_SHIFT-10),
781                 num_physpages << (PAGE_SHIFT-10),
782                 codesize >> 10,
783                 reservedpages << (PAGE_SHIFT-10),
784                 datasize >> 10,
785                 initsize >> 10,
786                 totalhigh_pages << (PAGE_SHIFT-10));
787
788         printk(KERN_INFO "virtual kernel memory layout:\n"
789                 "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
790 #ifdef CONFIG_HIGHMEM
791                 "    pkmap   : 0x%08lx - 0x%08lx   (%4ld kB)\n"
792 #endif
793                 "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
794                 "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
795                 "      .init : 0x%08lx - 0x%08lx   (%4ld kB)\n"
796                 "      .data : 0x%08lx - 0x%08lx   (%4ld kB)\n"
797                 "      .text : 0x%08lx - 0x%08lx   (%4ld kB)\n",
798                 FIXADDR_START, FIXADDR_TOP,
799                 (FIXADDR_TOP - FIXADDR_START) >> 10,
800
801 #ifdef CONFIG_HIGHMEM
802                 PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
803                 (LAST_PKMAP*PAGE_SIZE) >> 10,
804 #endif
805
806                 VMALLOC_START, VMALLOC_END,
807                 (VMALLOC_END - VMALLOC_START) >> 20,
808
809                 (unsigned long)__va(0), (unsigned long)high_memory,
810                 ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
811
812                 (unsigned long)&__init_begin, (unsigned long)&__init_end,
813                 ((unsigned long)&__init_end -
814                  (unsigned long)&__init_begin) >> 10,
815
816                 (unsigned long)&_etext, (unsigned long)&_edata,
817                 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
818
819                 (unsigned long)&_text, (unsigned long)&_etext,
820                 ((unsigned long)&_etext - (unsigned long)&_text) >> 10);
821
822         /*
823          * Check boundaries twice: Some fundamental inconsistencies can
824          * be detected at build time already.
825          */
826 #define __FIXADDR_TOP (-PAGE_SIZE)
827 #ifdef CONFIG_HIGHMEM
828         BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE  > FIXADDR_START);
829         BUILD_BUG_ON(VMALLOC_END                        > PKMAP_BASE);
830 #endif
831 #define high_memory (-128UL << 20)
832         BUILD_BUG_ON(VMALLOC_START                      >= VMALLOC_END);
833 #undef high_memory
834 #undef __FIXADDR_TOP
835
836 #ifdef CONFIG_HIGHMEM
837         BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE        > FIXADDR_START);
838         BUG_ON(VMALLOC_END                              > PKMAP_BASE);
839 #endif
840         BUG_ON(VMALLOC_START                            >= VMALLOC_END);
841         BUG_ON((unsigned long)high_memory               > VMALLOC_START);
842
843         if (boot_cpu_data.wp_works_ok < 0)
844                 test_wp_bit();
845 }
846
847 #ifdef CONFIG_MEMORY_HOTPLUG
848 int arch_add_memory(int nid, u64 start, u64 size)
849 {
850         struct pglist_data *pgdata = NODE_DATA(nid);
851         struct zone *zone = pgdata->node_zones + ZONE_HIGHMEM;
852         unsigned long start_pfn = start >> PAGE_SHIFT;
853         unsigned long nr_pages = size >> PAGE_SHIFT;
854
855         return __add_pages(nid, zone, start_pfn, nr_pages);
856 }
857 #endif
858
859 /*
860  * This function cannot be __init, since exceptions don't work in that
861  * section.  Put this after the callers, so that it cannot be inlined.
862  */
863 static noinline int do_test_wp_bit(void)
864 {
865         char tmp_reg;
866         int flag;
867
868         __asm__ __volatile__(
869                 "       movb %0, %1     \n"
870                 "1:     movb %1, %0     \n"
871                 "       xorl %2, %2     \n"
872                 "2:                     \n"
873                 _ASM_EXTABLE(1b,2b)
874                 :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)),
875                  "=q" (tmp_reg),
876                  "=r" (flag)
877                 :"2" (1)
878                 :"memory");
879
880         return flag;
881 }
882
883 #ifdef CONFIG_DEBUG_RODATA
884 const int rodata_test_data = 0xC3;
885 EXPORT_SYMBOL_GPL(rodata_test_data);
886
887 int kernel_set_to_readonly __read_mostly;
888
889 void set_kernel_text_rw(void)
890 {
891         unsigned long start = PFN_ALIGN(_text);
892         unsigned long size = PFN_ALIGN(_etext) - start;
893
894         if (!kernel_set_to_readonly)
895                 return;
896
897         pr_debug("Set kernel text: %lx - %lx for read write\n",
898                  start, start+size);
899
900         set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
901 }
902
903 void set_kernel_text_ro(void)
904 {
905         unsigned long start = PFN_ALIGN(_text);
906         unsigned long size = PFN_ALIGN(_etext) - start;
907
908         if (!kernel_set_to_readonly)
909                 return;
910
911         pr_debug("Set kernel text: %lx - %lx for read only\n",
912                  start, start+size);
913
914         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
915 }
916
917 static void mark_nxdata_nx(void)
918 {
919         /*
920          * When this called, init has already been executed and released,
921          * so everything past _etext sould be NX.
922          */
923         unsigned long start = PFN_ALIGN(_etext);
924         /*
925          * This comes from is_kernel_text upper limit. Also HPAGE where used:
926          */
927         unsigned long size = (((unsigned long)__init_end + HPAGE_SIZE) & HPAGE_MASK) - start;
928
929         if (__supported_pte_mask & _PAGE_NX)
930                 printk(KERN_INFO "NX-protecting the kernel data: %luk\n", size >> 10);
931         set_pages_nx(virt_to_page(start), size >> PAGE_SHIFT);
932 }
933
934 void mark_rodata_ro(void)
935 {
936         unsigned long start = PFN_ALIGN(_text);
937         unsigned long size = PFN_ALIGN(_etext) - start;
938
939         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
940         printk(KERN_INFO "Write protecting the kernel text: %luk\n",
941                 size >> 10);
942
943         kernel_set_to_readonly = 1;
944
945 #ifdef CONFIG_CPA_DEBUG
946         printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n",
947                 start, start+size);
948         set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT);
949
950         printk(KERN_INFO "Testing CPA: write protecting again\n");
951         set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT);
952 #endif
953
954         start += size;
955         size = (unsigned long)__end_rodata - start;
956         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
957         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
958                 size >> 10);
959         rodata_test();
960
961 #ifdef CONFIG_CPA_DEBUG
962         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size);
963         set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
964
965         printk(KERN_INFO "Testing CPA: write protecting again\n");
966         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
967 #endif
968         mark_nxdata_nx();
969 }
970 #endif
971