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x86-32, mm: Add an initial page table for core bootstrapping
[~shefty/rdma-dev.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/proc_fs.h>
29 #include <linux/memory_hotplug.h>
30 #include <linux/initrd.h>
31 #include <linux/cpumask.h>
32 #include <linux/gfp.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/page_types.h>
53 #include <asm/init.h>
54
55 unsigned long highstart_pfn, highend_pfn;
56
57 static noinline int do_test_wp_bit(void);
58
59 bool __read_mostly __vmalloc_start_set = false;
60
61 static __init void *alloc_low_page(void)
62 {
63         unsigned long pfn = e820_table_end++;
64         void *adr;
65
66         if (pfn >= e820_table_top)
67                 panic("alloc_low_page: ran out of memory");
68
69         adr = __va(pfn * PAGE_SIZE);
70         clear_page(adr);
71         return adr;
72 }
73
74 /*
75  * Creates a middle page table and puts a pointer to it in the
76  * given global directory entry. This only returns the gd entry
77  * in non-PAE compilation mode, since the middle layer is folded.
78  */
79 static pmd_t * __init one_md_table_init(pgd_t *pgd)
80 {
81         pud_t *pud;
82         pmd_t *pmd_table;
83
84 #ifdef CONFIG_X86_PAE
85         if (!(pgd_val(*pgd) & _PAGE_PRESENT)) {
86                 if (after_bootmem)
87                         pmd_table = (pmd_t *)alloc_bootmem_pages(PAGE_SIZE);
88                 else
89                         pmd_table = (pmd_t *)alloc_low_page();
90                 paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT);
91                 set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
92                 pud = pud_offset(pgd, 0);
93                 BUG_ON(pmd_table != pmd_offset(pud, 0));
94
95                 return pmd_table;
96         }
97 #endif
98         pud = pud_offset(pgd, 0);
99         pmd_table = pmd_offset(pud, 0);
100
101         return pmd_table;
102 }
103
104 /*
105  * Create a page table and place a pointer to it in a middle page
106  * directory entry:
107  */
108 static pte_t * __init one_page_table_init(pmd_t *pmd)
109 {
110         if (!(pmd_val(*pmd) & _PAGE_PRESENT)) {
111                 pte_t *page_table = NULL;
112
113                 if (after_bootmem) {
114 #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KMEMCHECK)
115                         page_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);
116 #endif
117                         if (!page_table)
118                                 page_table =
119                                 (pte_t *)alloc_bootmem_pages(PAGE_SIZE);
120                 } else
121                         page_table = (pte_t *)alloc_low_page();
122
123                 paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT);
124                 set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE));
125                 BUG_ON(page_table != pte_offset_kernel(pmd, 0));
126         }
127
128         return pte_offset_kernel(pmd, 0);
129 }
130
131 pmd_t * __init populate_extra_pmd(unsigned long vaddr)
132 {
133         int pgd_idx = pgd_index(vaddr);
134         int pmd_idx = pmd_index(vaddr);
135
136         return one_md_table_init(swapper_pg_dir + pgd_idx) + pmd_idx;
137 }
138
139 pte_t * __init populate_extra_pte(unsigned long vaddr)
140 {
141         int pte_idx = pte_index(vaddr);
142         pmd_t *pmd;
143
144         pmd = populate_extra_pmd(vaddr);
145         return one_page_table_init(pmd) + pte_idx;
146 }
147
148 static pte_t *__init page_table_kmap_check(pte_t *pte, pmd_t *pmd,
149                                            unsigned long vaddr, pte_t *lastpte)
150 {
151 #ifdef CONFIG_HIGHMEM
152         /*
153          * Something (early fixmap) may already have put a pte
154          * page here, which causes the page table allocation
155          * to become nonlinear. Attempt to fix it, and if it
156          * is still nonlinear then we have to bug.
157          */
158         int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT;
159         int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT;
160
161         if (pmd_idx_kmap_begin != pmd_idx_kmap_end
162             && (vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin
163             && (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end
164             && ((__pa(pte) >> PAGE_SHIFT) < e820_table_start
165                 || (__pa(pte) >> PAGE_SHIFT) >= e820_table_end)) {
166                 pte_t *newpte;
167                 int i;
168
169                 BUG_ON(after_bootmem);
170                 newpte = alloc_low_page();
171                 for (i = 0; i < PTRS_PER_PTE; i++)
172                         set_pte(newpte + i, pte[i]);
173
174                 paravirt_alloc_pte(&init_mm, __pa(newpte) >> PAGE_SHIFT);
175                 set_pmd(pmd, __pmd(__pa(newpte)|_PAGE_TABLE));
176                 BUG_ON(newpte != pte_offset_kernel(pmd, 0));
177                 __flush_tlb_all();
178
179                 paravirt_release_pte(__pa(pte) >> PAGE_SHIFT);
180                 pte = newpte;
181         }
182         BUG_ON(vaddr < fix_to_virt(FIX_KMAP_BEGIN - 1)
183                && vaddr > fix_to_virt(FIX_KMAP_END)
184                && lastpte && lastpte + PTRS_PER_PTE != pte);
185 #endif
186         return pte;
187 }
188
189 /*
190  * This function initializes a certain range of kernel virtual memory
191  * with new bootmem page tables, everywhere page tables are missing in
192  * the given range.
193  *
194  * NOTE: The pagetables are allocated contiguous on the physical space
195  * so we can cache the place of the first one and move around without
196  * checking the pgd every time.
197  */
198 static void __init
199 page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base)
200 {
201         int pgd_idx, pmd_idx;
202         unsigned long vaddr;
203         pgd_t *pgd;
204         pmd_t *pmd;
205         pte_t *pte = NULL;
206
207         vaddr = start;
208         pgd_idx = pgd_index(vaddr);
209         pmd_idx = pmd_index(vaddr);
210         pgd = pgd_base + pgd_idx;
211
212         for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
213                 pmd = one_md_table_init(pgd);
214                 pmd = pmd + pmd_index(vaddr);
215                 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);
216                                                         pmd++, pmd_idx++) {
217                         pte = page_table_kmap_check(one_page_table_init(pmd),
218                                                     pmd, vaddr, pte);
219
220                         vaddr += PMD_SIZE;
221                 }
222                 pmd_idx = 0;
223         }
224 }
225
226 static inline int is_kernel_text(unsigned long addr)
227 {
228         if (addr >= PAGE_OFFSET && addr <= (unsigned long)__init_end)
229                 return 1;
230         return 0;
231 }
232
233 /*
234  * This maps the physical memory to kernel virtual address space, a total
235  * of max_low_pfn pages, by creating page tables starting from address
236  * PAGE_OFFSET:
237  */
238 unsigned long __init
239 kernel_physical_mapping_init(unsigned long start,
240                              unsigned long end,
241                              unsigned long page_size_mask)
242 {
243         int use_pse = page_size_mask == (1<<PG_LEVEL_2M);
244         unsigned long last_map_addr = end;
245         unsigned long start_pfn, end_pfn;
246         pgd_t *pgd_base = swapper_pg_dir;
247         int pgd_idx, pmd_idx, pte_ofs;
248         unsigned long pfn;
249         pgd_t *pgd;
250         pmd_t *pmd;
251         pte_t *pte;
252         unsigned pages_2m, pages_4k;
253         int mapping_iter;
254
255         start_pfn = start >> PAGE_SHIFT;
256         end_pfn = end >> PAGE_SHIFT;
257
258         /*
259          * First iteration will setup identity mapping using large/small pages
260          * based on use_pse, with other attributes same as set by
261          * the early code in head_32.S
262          *
263          * Second iteration will setup the appropriate attributes (NX, GLOBAL..)
264          * as desired for the kernel identity mapping.
265          *
266          * This two pass mechanism conforms to the TLB app note which says:
267          *
268          *     "Software should not write to a paging-structure entry in a way
269          *      that would change, for any linear address, both the page size
270          *      and either the page frame or attributes."
271          */
272         mapping_iter = 1;
273
274         if (!cpu_has_pse)
275                 use_pse = 0;
276
277 repeat:
278         pages_2m = pages_4k = 0;
279         pfn = start_pfn;
280         pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
281         pgd = pgd_base + pgd_idx;
282         for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) {
283                 pmd = one_md_table_init(pgd);
284
285                 if (pfn >= end_pfn)
286                         continue;
287 #ifdef CONFIG_X86_PAE
288                 pmd_idx = pmd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
289                 pmd += pmd_idx;
290 #else
291                 pmd_idx = 0;
292 #endif
293                 for (; pmd_idx < PTRS_PER_PMD && pfn < end_pfn;
294                      pmd++, pmd_idx++) {
295                         unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET;
296
297                         /*
298                          * Map with big pages if possible, otherwise
299                          * create normal page tables:
300                          */
301                         if (use_pse) {
302                                 unsigned int addr2;
303                                 pgprot_t prot = PAGE_KERNEL_LARGE;
304                                 /*
305                                  * first pass will use the same initial
306                                  * identity mapping attribute + _PAGE_PSE.
307                                  */
308                                 pgprot_t init_prot =
309                                         __pgprot(PTE_IDENT_ATTR |
310                                                  _PAGE_PSE);
311
312                                 addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE +
313                                         PAGE_OFFSET + PAGE_SIZE-1;
314
315                                 if (is_kernel_text(addr) ||
316                                     is_kernel_text(addr2))
317                                         prot = PAGE_KERNEL_LARGE_EXEC;
318
319                                 pages_2m++;
320                                 if (mapping_iter == 1)
321                                         set_pmd(pmd, pfn_pmd(pfn, init_prot));
322                                 else
323                                         set_pmd(pmd, pfn_pmd(pfn, prot));
324
325                                 pfn += PTRS_PER_PTE;
326                                 continue;
327                         }
328                         pte = one_page_table_init(pmd);
329
330                         pte_ofs = pte_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
331                         pte += pte_ofs;
332                         for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn;
333                              pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) {
334                                 pgprot_t prot = PAGE_KERNEL;
335                                 /*
336                                  * first pass will use the same initial
337                                  * identity mapping attribute.
338                                  */
339                                 pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR);
340
341                                 if (is_kernel_text(addr))
342                                         prot = PAGE_KERNEL_EXEC;
343
344                                 pages_4k++;
345                                 if (mapping_iter == 1) {
346                                         set_pte(pte, pfn_pte(pfn, init_prot));
347                                         last_map_addr = (pfn << PAGE_SHIFT) + PAGE_SIZE;
348                                 } else
349                                         set_pte(pte, pfn_pte(pfn, prot));
350                         }
351                 }
352         }
353         if (mapping_iter == 1) {
354                 /*
355                  * update direct mapping page count only in the first
356                  * iteration.
357                  */
358                 update_page_count(PG_LEVEL_2M, pages_2m);
359                 update_page_count(PG_LEVEL_4K, pages_4k);
360
361                 /*
362                  * local global flush tlb, which will flush the previous
363                  * mappings present in both small and large page TLB's.
364                  */
365                 __flush_tlb_all();
366
367                 /*
368                  * Second iteration will set the actual desired PTE attributes.
369                  */
370                 mapping_iter = 2;
371                 goto repeat;
372         }
373         return last_map_addr;
374 }
375
376 pte_t *kmap_pte;
377 pgprot_t kmap_prot;
378
379 static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr)
380 {
381         return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
382                         vaddr), vaddr), vaddr);
383 }
384
385 static void __init kmap_init(void)
386 {
387         unsigned long kmap_vstart;
388
389         /*
390          * Cache the first kmap pte:
391          */
392         kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
393         kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
394
395         kmap_prot = PAGE_KERNEL;
396 }
397
398 #ifdef CONFIG_HIGHMEM
399 static void __init permanent_kmaps_init(pgd_t *pgd_base)
400 {
401         unsigned long vaddr;
402         pgd_t *pgd;
403         pud_t *pud;
404         pmd_t *pmd;
405         pte_t *pte;
406
407         vaddr = PKMAP_BASE;
408         page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
409
410         pgd = swapper_pg_dir + pgd_index(vaddr);
411         pud = pud_offset(pgd, vaddr);
412         pmd = pmd_offset(pud, vaddr);
413         pte = pte_offset_kernel(pmd, vaddr);
414         pkmap_page_table = pte;
415 }
416
417 static void __init add_one_highpage_init(struct page *page)
418 {
419         ClearPageReserved(page);
420         init_page_count(page);
421         __free_page(page);
422         totalhigh_pages++;
423 }
424
425 struct add_highpages_data {
426         unsigned long start_pfn;
427         unsigned long end_pfn;
428 };
429
430 static int __init add_highpages_work_fn(unsigned long start_pfn,
431                                          unsigned long end_pfn, void *datax)
432 {
433         int node_pfn;
434         struct page *page;
435         unsigned long final_start_pfn, final_end_pfn;
436         struct add_highpages_data *data;
437
438         data = (struct add_highpages_data *)datax;
439
440         final_start_pfn = max(start_pfn, data->start_pfn);
441         final_end_pfn = min(end_pfn, data->end_pfn);
442         if (final_start_pfn >= final_end_pfn)
443                 return 0;
444
445         for (node_pfn = final_start_pfn; node_pfn < final_end_pfn;
446              node_pfn++) {
447                 if (!pfn_valid(node_pfn))
448                         continue;
449                 page = pfn_to_page(node_pfn);
450                 add_one_highpage_init(page);
451         }
452
453         return 0;
454
455 }
456
457 void __init add_highpages_with_active_regions(int nid, unsigned long start_pfn,
458                                               unsigned long end_pfn)
459 {
460         struct add_highpages_data data;
461
462         data.start_pfn = start_pfn;
463         data.end_pfn = end_pfn;
464
465         work_with_active_regions(nid, add_highpages_work_fn, &data);
466 }
467
468 #else
469 static inline void permanent_kmaps_init(pgd_t *pgd_base)
470 {
471 }
472 #endif /* CONFIG_HIGHMEM */
473
474 void __init native_pagetable_setup_start(pgd_t *base)
475 {
476         unsigned long pfn, va;
477         pgd_t *pgd;
478         pud_t *pud;
479         pmd_t *pmd;
480         pte_t *pte;
481
482         /*
483          * Remove any mappings which extend past the end of physical
484          * memory from the boot time page table:
485          */
486         for (pfn = max_low_pfn + 1; pfn < 1<<(32-PAGE_SHIFT); pfn++) {
487                 va = PAGE_OFFSET + (pfn<<PAGE_SHIFT);
488                 pgd = base + pgd_index(va);
489                 if (!pgd_present(*pgd))
490                         break;
491
492                 pud = pud_offset(pgd, va);
493                 pmd = pmd_offset(pud, va);
494                 if (!pmd_present(*pmd))
495                         break;
496
497                 pte = pte_offset_kernel(pmd, va);
498                 if (!pte_present(*pte))
499                         break;
500
501                 pte_clear(NULL, va, pte);
502         }
503         paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT);
504 }
505
506 void __init native_pagetable_setup_done(pgd_t *base)
507 {
508 }
509
510 /*
511  * Build a proper pagetable for the kernel mappings.  Up until this
512  * point, we've been running on some set of pagetables constructed by
513  * the boot process.
514  *
515  * If we're booting on native hardware, this will be a pagetable
516  * constructed in arch/x86/kernel/head_32.S.  The root of the
517  * pagetable will be swapper_pg_dir.
518  *
519  * If we're booting paravirtualized under a hypervisor, then there are
520  * more options: we may already be running PAE, and the pagetable may
521  * or may not be based in swapper_pg_dir.  In any case,
522  * paravirt_pagetable_setup_start() will set up swapper_pg_dir
523  * appropriately for the rest of the initialization to work.
524  *
525  * In general, pagetable_init() assumes that the pagetable may already
526  * be partially populated, and so it avoids stomping on any existing
527  * mappings.
528  */
529 void __init early_ioremap_page_table_range_init(void)
530 {
531         pgd_t *pgd_base = swapper_pg_dir;
532         unsigned long vaddr, end;
533
534         /*
535          * Fixed mappings, only the page table structure has to be
536          * created - mappings will be set by set_fixmap():
537          */
538         vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
539         end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
540         page_table_range_init(vaddr, end, pgd_base);
541         early_ioremap_reset();
542 }
543
544 static void __init pagetable_init(void)
545 {
546         pgd_t *pgd_base = swapper_pg_dir;
547
548         permanent_kmaps_init(pgd_base);
549 }
550
551 pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL | _PAGE_IOMAP);
552 EXPORT_SYMBOL_GPL(__supported_pte_mask);
553
554 /* user-defined highmem size */
555 static unsigned int highmem_pages = -1;
556
557 /*
558  * highmem=size forces highmem to be exactly 'size' bytes.
559  * This works even on boxes that have no highmem otherwise.
560  * This also works to reduce highmem size on bigger boxes.
561  */
562 static int __init parse_highmem(char *arg)
563 {
564         if (!arg)
565                 return -EINVAL;
566
567         highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT;
568         return 0;
569 }
570 early_param("highmem", parse_highmem);
571
572 #define MSG_HIGHMEM_TOO_BIG \
573         "highmem size (%luMB) is bigger than pages available (%luMB)!\n"
574
575 #define MSG_LOWMEM_TOO_SMALL \
576         "highmem size (%luMB) results in <64MB lowmem, ignoring it!\n"
577 /*
578  * All of RAM fits into lowmem - but if user wants highmem
579  * artificially via the highmem=x boot parameter then create
580  * it:
581  */
582 void __init lowmem_pfn_init(void)
583 {
584         /* max_low_pfn is 0, we already have early_res support */
585         max_low_pfn = max_pfn;
586
587         if (highmem_pages == -1)
588                 highmem_pages = 0;
589 #ifdef CONFIG_HIGHMEM
590         if (highmem_pages >= max_pfn) {
591                 printk(KERN_ERR MSG_HIGHMEM_TOO_BIG,
592                         pages_to_mb(highmem_pages), pages_to_mb(max_pfn));
593                 highmem_pages = 0;
594         }
595         if (highmem_pages) {
596                 if (max_low_pfn - highmem_pages < 64*1024*1024/PAGE_SIZE) {
597                         printk(KERN_ERR MSG_LOWMEM_TOO_SMALL,
598                                 pages_to_mb(highmem_pages));
599                         highmem_pages = 0;
600                 }
601                 max_low_pfn -= highmem_pages;
602         }
603 #else
604         if (highmem_pages)
605                 printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n");
606 #endif
607 }
608
609 #define MSG_HIGHMEM_TOO_SMALL \
610         "only %luMB highmem pages available, ignoring highmem size of %luMB!\n"
611
612 #define MSG_HIGHMEM_TRIMMED \
613         "Warning: only 4GB will be used. Use a HIGHMEM64G enabled kernel!\n"
614 /*
615  * We have more RAM than fits into lowmem - we try to put it into
616  * highmem, also taking the highmem=x boot parameter into account:
617  */
618 void __init highmem_pfn_init(void)
619 {
620         max_low_pfn = MAXMEM_PFN;
621
622         if (highmem_pages == -1)
623                 highmem_pages = max_pfn - MAXMEM_PFN;
624
625         if (highmem_pages + MAXMEM_PFN < max_pfn)
626                 max_pfn = MAXMEM_PFN + highmem_pages;
627
628         if (highmem_pages + MAXMEM_PFN > max_pfn) {
629                 printk(KERN_WARNING MSG_HIGHMEM_TOO_SMALL,
630                         pages_to_mb(max_pfn - MAXMEM_PFN),
631                         pages_to_mb(highmem_pages));
632                 highmem_pages = 0;
633         }
634 #ifndef CONFIG_HIGHMEM
635         /* Maximum memory usable is what is directly addressable */
636         printk(KERN_WARNING "Warning only %ldMB will be used.\n", MAXMEM>>20);
637         if (max_pfn > MAX_NONPAE_PFN)
638                 printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n");
639         else
640                 printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");
641         max_pfn = MAXMEM_PFN;
642 #else /* !CONFIG_HIGHMEM */
643 #ifndef CONFIG_HIGHMEM64G
644         if (max_pfn > MAX_NONPAE_PFN) {
645                 max_pfn = MAX_NONPAE_PFN;
646                 printk(KERN_WARNING MSG_HIGHMEM_TRIMMED);
647         }
648 #endif /* !CONFIG_HIGHMEM64G */
649 #endif /* !CONFIG_HIGHMEM */
650 }
651
652 /*
653  * Determine low and high memory ranges:
654  */
655 void __init find_low_pfn_range(void)
656 {
657         /* it could update max_pfn */
658
659         if (max_pfn <= MAXMEM_PFN)
660                 lowmem_pfn_init();
661         else
662                 highmem_pfn_init();
663 }
664
665 #ifndef CONFIG_NEED_MULTIPLE_NODES
666 void __init initmem_init(unsigned long start_pfn, unsigned long end_pfn,
667                                 int acpi, int k8)
668 {
669 #ifdef CONFIG_HIGHMEM
670         highstart_pfn = highend_pfn = max_pfn;
671         if (max_pfn > max_low_pfn)
672                 highstart_pfn = max_low_pfn;
673         e820_register_active_regions(0, 0, highend_pfn);
674         sparse_memory_present_with_active_regions(0);
675         printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
676                 pages_to_mb(highend_pfn - highstart_pfn));
677         num_physpages = highend_pfn;
678         high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1;
679 #else
680         e820_register_active_regions(0, 0, max_low_pfn);
681         sparse_memory_present_with_active_regions(0);
682         num_physpages = max_low_pfn;
683         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1;
684 #endif
685 #ifdef CONFIG_FLATMEM
686         max_mapnr = num_physpages;
687 #endif
688         __vmalloc_start_set = true;
689
690         printk(KERN_NOTICE "%ldMB LOWMEM available.\n",
691                         pages_to_mb(max_low_pfn));
692
693         setup_bootmem_allocator();
694 }
695 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
696
697 static void __init zone_sizes_init(void)
698 {
699         unsigned long max_zone_pfns[MAX_NR_ZONES];
700         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
701         max_zone_pfns[ZONE_DMA] =
702                 virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
703         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
704 #ifdef CONFIG_HIGHMEM
705         max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
706 #endif
707
708         free_area_init_nodes(max_zone_pfns);
709 }
710
711 #ifndef CONFIG_NO_BOOTMEM
712 static unsigned long __init setup_node_bootmem(int nodeid,
713                                  unsigned long start_pfn,
714                                  unsigned long end_pfn,
715                                  unsigned long bootmap)
716 {
717         unsigned long bootmap_size;
718
719         /* don't touch min_low_pfn */
720         bootmap_size = init_bootmem_node(NODE_DATA(nodeid),
721                                          bootmap >> PAGE_SHIFT,
722                                          start_pfn, end_pfn);
723         printk(KERN_INFO "  node %d low ram: %08lx - %08lx\n",
724                 nodeid, start_pfn<<PAGE_SHIFT, end_pfn<<PAGE_SHIFT);
725         printk(KERN_INFO "  node %d bootmap %08lx - %08lx\n",
726                  nodeid, bootmap, bootmap + bootmap_size);
727         free_bootmem_with_active_regions(nodeid, end_pfn);
728
729         return bootmap + bootmap_size;
730 }
731 #endif
732
733 void __init setup_bootmem_allocator(void)
734 {
735 #ifndef CONFIG_NO_BOOTMEM
736         int nodeid;
737         unsigned long bootmap_size, bootmap;
738         /*
739          * Initialize the boot-time allocator (with low memory only):
740          */
741         bootmap_size = bootmem_bootmap_pages(max_low_pfn)<<PAGE_SHIFT;
742         bootmap = find_e820_area(0, max_pfn_mapped<<PAGE_SHIFT, bootmap_size,
743                                  PAGE_SIZE);
744         if (bootmap == -1L)
745                 panic("Cannot find bootmem map of size %ld\n", bootmap_size);
746         reserve_early(bootmap, bootmap + bootmap_size, "BOOTMAP");
747 #endif
748
749         printk(KERN_INFO "  mapped low ram: 0 - %08lx\n",
750                  max_pfn_mapped<<PAGE_SHIFT);
751         printk(KERN_INFO "  low ram: 0 - %08lx\n", max_low_pfn<<PAGE_SHIFT);
752
753 #ifndef CONFIG_NO_BOOTMEM
754         for_each_online_node(nodeid) {
755                  unsigned long start_pfn, end_pfn;
756
757 #ifdef CONFIG_NEED_MULTIPLE_NODES
758                 start_pfn = node_start_pfn[nodeid];
759                 end_pfn = node_end_pfn[nodeid];
760                 if (start_pfn > max_low_pfn)
761                         continue;
762                 if (end_pfn > max_low_pfn)
763                         end_pfn = max_low_pfn;
764 #else
765                 start_pfn = 0;
766                 end_pfn = max_low_pfn;
767 #endif
768                 bootmap = setup_node_bootmem(nodeid, start_pfn, end_pfn,
769                                                  bootmap);
770         }
771 #endif
772
773         after_bootmem = 1;
774 }
775
776 /*
777  * paging_init() sets up the page tables - note that the first 8MB are
778  * already mapped by head.S.
779  *
780  * This routines also unmaps the page at virtual kernel address 0, so
781  * that we can trap those pesky NULL-reference errors in the kernel.
782  */
783 void __init paging_init(void)
784 {
785         pagetable_init();
786
787         __flush_tlb_all();
788
789         kmap_init();
790
791         /*
792          * NOTE: at this point the bootmem allocator is fully available.
793          */
794         sparse_init();
795         zone_sizes_init();
796 }
797
798 /*
799  * Test if the WP bit works in supervisor mode. It isn't supported on 386's
800  * and also on some strange 486's. All 586+'s are OK. This used to involve
801  * black magic jumps to work around some nasty CPU bugs, but fortunately the
802  * switch to using exceptions got rid of all that.
803  */
804 static void __init test_wp_bit(void)
805 {
806         printk(KERN_INFO
807   "Checking if this processor honours the WP bit even in supervisor mode...");
808
809         /* Any page-aligned address will do, the test is non-destructive */
810         __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_READONLY);
811         boot_cpu_data.wp_works_ok = do_test_wp_bit();
812         clear_fixmap(FIX_WP_TEST);
813
814         if (!boot_cpu_data.wp_works_ok) {
815                 printk(KERN_CONT "No.\n");
816 #ifdef CONFIG_X86_WP_WORKS_OK
817                 panic(
818   "This kernel doesn't support CPU's with broken WP. Recompile it for a 386!");
819 #endif
820         } else {
821                 printk(KERN_CONT "Ok.\n");
822         }
823 }
824
825 void __init mem_init(void)
826 {
827         int codesize, reservedpages, datasize, initsize;
828         int tmp;
829
830         pci_iommu_alloc();
831
832 #ifdef CONFIG_FLATMEM
833         BUG_ON(!mem_map);
834 #endif
835         /* this will put all low memory onto the freelists */
836         totalram_pages += free_all_bootmem();
837
838         reservedpages = 0;
839         for (tmp = 0; tmp < max_low_pfn; tmp++)
840                 /*
841                  * Only count reserved RAM pages:
842                  */
843                 if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp)))
844                         reservedpages++;
845
846         set_highmem_pages_init();
847
848         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
849         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
850         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
851
852         printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
853                         "%dk reserved, %dk data, %dk init, %ldk highmem)\n",
854                 nr_free_pages() << (PAGE_SHIFT-10),
855                 num_physpages << (PAGE_SHIFT-10),
856                 codesize >> 10,
857                 reservedpages << (PAGE_SHIFT-10),
858                 datasize >> 10,
859                 initsize >> 10,
860                 totalhigh_pages << (PAGE_SHIFT-10));
861
862         printk(KERN_INFO "virtual kernel memory layout:\n"
863                 "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
864 #ifdef CONFIG_HIGHMEM
865                 "    pkmap   : 0x%08lx - 0x%08lx   (%4ld kB)\n"
866 #endif
867                 "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
868                 "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
869                 "      .init : 0x%08lx - 0x%08lx   (%4ld kB)\n"
870                 "      .data : 0x%08lx - 0x%08lx   (%4ld kB)\n"
871                 "      .text : 0x%08lx - 0x%08lx   (%4ld kB)\n",
872                 FIXADDR_START, FIXADDR_TOP,
873                 (FIXADDR_TOP - FIXADDR_START) >> 10,
874
875 #ifdef CONFIG_HIGHMEM
876                 PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
877                 (LAST_PKMAP*PAGE_SIZE) >> 10,
878 #endif
879
880                 VMALLOC_START, VMALLOC_END,
881                 (VMALLOC_END - VMALLOC_START) >> 20,
882
883                 (unsigned long)__va(0), (unsigned long)high_memory,
884                 ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
885
886                 (unsigned long)&__init_begin, (unsigned long)&__init_end,
887                 ((unsigned long)&__init_end -
888                  (unsigned long)&__init_begin) >> 10,
889
890                 (unsigned long)&_etext, (unsigned long)&_edata,
891                 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
892
893                 (unsigned long)&_text, (unsigned long)&_etext,
894                 ((unsigned long)&_etext - (unsigned long)&_text) >> 10);
895
896         /*
897          * Check boundaries twice: Some fundamental inconsistencies can
898          * be detected at build time already.
899          */
900 #define __FIXADDR_TOP (-PAGE_SIZE)
901 #ifdef CONFIG_HIGHMEM
902         BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE  > FIXADDR_START);
903         BUILD_BUG_ON(VMALLOC_END                        > PKMAP_BASE);
904 #endif
905 #define high_memory (-128UL << 20)
906         BUILD_BUG_ON(VMALLOC_START                      >= VMALLOC_END);
907 #undef high_memory
908 #undef __FIXADDR_TOP
909
910 #ifdef CONFIG_HIGHMEM
911         BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE        > FIXADDR_START);
912         BUG_ON(VMALLOC_END                              > PKMAP_BASE);
913 #endif
914         BUG_ON(VMALLOC_START                            >= VMALLOC_END);
915         BUG_ON((unsigned long)high_memory               > VMALLOC_START);
916
917         if (boot_cpu_data.wp_works_ok < 0)
918                 test_wp_bit();
919 }
920
921 #ifdef CONFIG_MEMORY_HOTPLUG
922 int arch_add_memory(int nid, u64 start, u64 size)
923 {
924         struct pglist_data *pgdata = NODE_DATA(nid);
925         struct zone *zone = pgdata->node_zones + ZONE_HIGHMEM;
926         unsigned long start_pfn = start >> PAGE_SHIFT;
927         unsigned long nr_pages = size >> PAGE_SHIFT;
928
929         return __add_pages(nid, zone, start_pfn, nr_pages);
930 }
931 #endif
932
933 /*
934  * This function cannot be __init, since exceptions don't work in that
935  * section.  Put this after the callers, so that it cannot be inlined.
936  */
937 static noinline int do_test_wp_bit(void)
938 {
939         char tmp_reg;
940         int flag;
941
942         __asm__ __volatile__(
943                 "       movb %0, %1     \n"
944                 "1:     movb %1, %0     \n"
945                 "       xorl %2, %2     \n"
946                 "2:                     \n"
947                 _ASM_EXTABLE(1b,2b)
948                 :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)),
949                  "=q" (tmp_reg),
950                  "=r" (flag)
951                 :"2" (1)
952                 :"memory");
953
954         return flag;
955 }
956
957 #ifdef CONFIG_DEBUG_RODATA
958 const int rodata_test_data = 0xC3;
959 EXPORT_SYMBOL_GPL(rodata_test_data);
960
961 int kernel_set_to_readonly __read_mostly;
962
963 void set_kernel_text_rw(void)
964 {
965         unsigned long start = PFN_ALIGN(_text);
966         unsigned long size = PFN_ALIGN(_etext) - start;
967
968         if (!kernel_set_to_readonly)
969                 return;
970
971         pr_debug("Set kernel text: %lx - %lx for read write\n",
972                  start, start+size);
973
974         set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
975 }
976
977 void set_kernel_text_ro(void)
978 {
979         unsigned long start = PFN_ALIGN(_text);
980         unsigned long size = PFN_ALIGN(_etext) - start;
981
982         if (!kernel_set_to_readonly)
983                 return;
984
985         pr_debug("Set kernel text: %lx - %lx for read only\n",
986                  start, start+size);
987
988         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
989 }
990
991 void mark_rodata_ro(void)
992 {
993         unsigned long start = PFN_ALIGN(_text);
994         unsigned long size = PFN_ALIGN(_etext) - start;
995
996         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
997         printk(KERN_INFO "Write protecting the kernel text: %luk\n",
998                 size >> 10);
999
1000         kernel_set_to_readonly = 1;
1001
1002 #ifdef CONFIG_CPA_DEBUG
1003         printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n",
1004                 start, start+size);
1005         set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT);
1006
1007         printk(KERN_INFO "Testing CPA: write protecting again\n");
1008         set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT);
1009 #endif
1010
1011         start += size;
1012         size = (unsigned long)__end_rodata - start;
1013         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
1014         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
1015                 size >> 10);
1016         rodata_test();
1017
1018 #ifdef CONFIG_CPA_DEBUG
1019         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size);
1020         set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
1021
1022         printk(KERN_INFO "Testing CPA: write protecting again\n");
1023         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
1024 #endif
1025 }
1026 #endif
1027
1028 int __init reserve_bootmem_generic(unsigned long phys, unsigned long len,
1029                                    int flags)
1030 {
1031         return reserve_bootmem(phys, len, flags);
1032 }