63b09bae250940349d492693a5fee704577a6ab1
[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/pgalloc.h>
49 #include <asm/sections.h>
50 #include <asm/paravirt.h>
51 #include <asm/setup.h>
52 #include <asm/cacheflush.h>
53 #include <asm/page_types.h>
54 #include <asm/init.h>
55
56 unsigned long highstart_pfn, highend_pfn;
57
58 static noinline int do_test_wp_bit(void);
59
60 bool __read_mostly __vmalloc_start_set = false;
61
62 static __init void *alloc_low_page(void)
63 {
64         unsigned long pfn = e820_table_end++;
65         void *adr;
66
67         if (pfn >= e820_table_top)
68                 panic("alloc_low_page: ran out of memory");
69
70         adr = __va(pfn * PAGE_SIZE);
71         memset(adr, 0, PAGE_SIZE);
72         return adr;
73 }
74
75 /*
76  * Creates a middle page table and puts a pointer to it in the
77  * given global directory entry. This only returns the gd entry
78  * in non-PAE compilation mode, since the middle layer is folded.
79  */
80 static pmd_t * __init one_md_table_init(pgd_t *pgd)
81 {
82         pud_t *pud;
83         pmd_t *pmd_table;
84
85 #ifdef CONFIG_X86_PAE
86         if (!(pgd_val(*pgd) & _PAGE_PRESENT)) {
87                 if (after_bootmem)
88                         pmd_table = (pmd_t *)alloc_bootmem_pages(PAGE_SIZE);
89                 else
90                         pmd_table = (pmd_t *)alloc_low_page();
91                 paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT);
92                 set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
93                 pud = pud_offset(pgd, 0);
94                 BUG_ON(pmd_table != pmd_offset(pud, 0));
95
96                 return pmd_table;
97         }
98 #endif
99         pud = pud_offset(pgd, 0);
100         pmd_table = pmd_offset(pud, 0);
101
102         return pmd_table;
103 }
104
105 /*
106  * Create a page table and place a pointer to it in a middle page
107  * directory entry:
108  */
109 static pte_t * __init one_page_table_init(pmd_t *pmd)
110 {
111         if (!(pmd_val(*pmd) & _PAGE_PRESENT)) {
112                 pte_t *page_table = NULL;
113
114                 if (after_bootmem) {
115 #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KMEMCHECK)
116                         page_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);
117 #endif
118                         if (!page_table)
119                                 page_table =
120                                 (pte_t *)alloc_bootmem_pages(PAGE_SIZE);
121                 } else
122                         page_table = (pte_t *)alloc_low_page();
123
124                 paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT);
125                 set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE));
126                 BUG_ON(page_table != pte_offset_kernel(pmd, 0));
127         }
128
129         return pte_offset_kernel(pmd, 0);
130 }
131
132 pmd_t * __init populate_extra_pmd(unsigned long vaddr)
133 {
134         int pgd_idx = pgd_index(vaddr);
135         int pmd_idx = pmd_index(vaddr);
136
137         return one_md_table_init(swapper_pg_dir + pgd_idx) + pmd_idx;
138 }
139
140 pte_t * __init populate_extra_pte(unsigned long vaddr)
141 {
142         int pte_idx = pte_index(vaddr);
143         pmd_t *pmd;
144
145         pmd = populate_extra_pmd(vaddr);
146         return one_page_table_init(pmd) + pte_idx;
147 }
148
149 static pte_t *__init page_table_kmap_check(pte_t *pte, pmd_t *pmd,
150                                            unsigned long vaddr, pte_t *lastpte)
151 {
152 #ifdef CONFIG_HIGHMEM
153         /*
154          * Something (early fixmap) may already have put a pte
155          * page here, which causes the page table allocation
156          * to become nonlinear. Attempt to fix it, and if it
157          * is still nonlinear then we have to bug.
158          */
159         int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT;
160         int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT;
161
162         if (pmd_idx_kmap_begin != pmd_idx_kmap_end
163             && (vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin
164             && (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end
165             && ((__pa(pte) >> PAGE_SHIFT) < e820_table_start
166                 || (__pa(pte) >> PAGE_SHIFT) >= e820_table_end)) {
167                 pte_t *newpte;
168                 int i;
169
170                 BUG_ON(after_bootmem);
171                 newpte = alloc_low_page();
172                 for (i = 0; i < PTRS_PER_PTE; i++)
173                         set_pte(newpte + i, pte[i]);
174
175                 paravirt_alloc_pte(&init_mm, __pa(newpte) >> PAGE_SHIFT);
176                 set_pmd(pmd, __pmd(__pa(newpte)|_PAGE_TABLE));
177                 BUG_ON(newpte != pte_offset_kernel(pmd, 0));
178                 __flush_tlb_all();
179
180                 paravirt_release_pte(__pa(pte) >> PAGE_SHIFT);
181                 pte = newpte;
182         }
183         BUG_ON(vaddr < fix_to_virt(FIX_KMAP_BEGIN - 1)
184                && vaddr > fix_to_virt(FIX_KMAP_END)
185                && lastpte && lastpte + PTRS_PER_PTE != pte);
186 #endif
187         return pte;
188 }
189
190 /*
191  * This function initializes a certain range of kernel virtual memory
192  * with new bootmem page tables, everywhere page tables are missing in
193  * the given range.
194  *
195  * NOTE: The pagetables are allocated contiguous on the physical space
196  * so we can cache the place of the first one and move around without
197  * checking the pgd every time.
198  */
199 static void __init
200 page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base)
201 {
202         int pgd_idx, pmd_idx;
203         unsigned long vaddr;
204         pgd_t *pgd;
205         pmd_t *pmd;
206         pte_t *pte = NULL;
207
208         vaddr = start;
209         pgd_idx = pgd_index(vaddr);
210         pmd_idx = pmd_index(vaddr);
211         pgd = pgd_base + pgd_idx;
212
213         for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
214                 pmd = one_md_table_init(pgd);
215                 pmd = pmd + pmd_index(vaddr);
216                 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);
217                                                         pmd++, pmd_idx++) {
218                         pte = page_table_kmap_check(one_page_table_init(pmd),
219                                                     pmd, vaddr, pte);
220
221                         vaddr += PMD_SIZE;
222                 }
223                 pmd_idx = 0;
224         }
225 }
226
227 static inline int is_kernel_text(unsigned long addr)
228 {
229         if (addr >= PAGE_OFFSET && addr <= (unsigned long)__init_end)
230                 return 1;
231         return 0;
232 }
233
234 /*
235  * This maps the physical memory to kernel virtual address space, a total
236  * of max_low_pfn pages, by creating page tables starting from address
237  * PAGE_OFFSET:
238  */
239 unsigned long __init
240 kernel_physical_mapping_init(unsigned long start,
241                              unsigned long end,
242                              unsigned long page_size_mask)
243 {
244         int use_pse = page_size_mask == (1<<PG_LEVEL_2M);
245         unsigned long last_map_addr = end;
246         unsigned long start_pfn, end_pfn;
247         pgd_t *pgd_base = swapper_pg_dir;
248         int pgd_idx, pmd_idx, pte_ofs;
249         unsigned long pfn;
250         pgd_t *pgd;
251         pmd_t *pmd;
252         pte_t *pte;
253         unsigned pages_2m, pages_4k;
254         int mapping_iter;
255
256         start_pfn = start >> PAGE_SHIFT;
257         end_pfn = end >> PAGE_SHIFT;
258
259         /*
260          * First iteration will setup identity mapping using large/small pages
261          * based on use_pse, with other attributes same as set by
262          * the early code in head_32.S
263          *
264          * Second iteration will setup the appropriate attributes (NX, GLOBAL..)
265          * as desired for the kernel identity mapping.
266          *
267          * This two pass mechanism conforms to the TLB app note which says:
268          *
269          *     "Software should not write to a paging-structure entry in a way
270          *      that would change, for any linear address, both the page size
271          *      and either the page frame or attributes."
272          */
273         mapping_iter = 1;
274
275         if (!cpu_has_pse)
276                 use_pse = 0;
277
278 repeat:
279         pages_2m = pages_4k = 0;
280         pfn = start_pfn;
281         pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
282         pgd = pgd_base + pgd_idx;
283         for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) {
284                 pmd = one_md_table_init(pgd);
285
286                 if (pfn >= end_pfn)
287                         continue;
288 #ifdef CONFIG_X86_PAE
289                 pmd_idx = pmd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
290                 pmd += pmd_idx;
291 #else
292                 pmd_idx = 0;
293 #endif
294                 for (; pmd_idx < PTRS_PER_PMD && pfn < end_pfn;
295                      pmd++, pmd_idx++) {
296                         unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET;
297
298                         /*
299                          * Map with big pages if possible, otherwise
300                          * create normal page tables:
301                          */
302                         if (use_pse) {
303                                 unsigned int addr2;
304                                 pgprot_t prot = PAGE_KERNEL_LARGE;
305                                 /*
306                                  * first pass will use the same initial
307                                  * identity mapping attribute + _PAGE_PSE.
308                                  */
309                                 pgprot_t init_prot =
310                                         __pgprot(PTE_IDENT_ATTR |
311                                                  _PAGE_PSE);
312
313                                 addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE +
314                                         PAGE_OFFSET + PAGE_SIZE-1;
315
316                                 if (is_kernel_text(addr) ||
317                                     is_kernel_text(addr2))
318                                         prot = PAGE_KERNEL_LARGE_EXEC;
319
320                                 pages_2m++;
321                                 if (mapping_iter == 1)
322                                         set_pmd(pmd, pfn_pmd(pfn, init_prot));
323                                 else
324                                         set_pmd(pmd, pfn_pmd(pfn, prot));
325
326                                 pfn += PTRS_PER_PTE;
327                                 continue;
328                         }
329                         pte = one_page_table_init(pmd);
330
331                         pte_ofs = pte_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
332                         pte += pte_ofs;
333                         for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn;
334                              pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) {
335                                 pgprot_t prot = PAGE_KERNEL;
336                                 /*
337                                  * first pass will use the same initial
338                                  * identity mapping attribute.
339                                  */
340                                 pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR);
341
342                                 if (is_kernel_text(addr))
343                                         prot = PAGE_KERNEL_EXEC;
344
345                                 pages_4k++;
346                                 if (mapping_iter == 1) {
347                                         set_pte(pte, pfn_pte(pfn, init_prot));
348                                         last_map_addr = (pfn << PAGE_SHIFT) + PAGE_SIZE;
349                                 } else
350                                         set_pte(pte, pfn_pte(pfn, prot));
351                         }
352                 }
353         }
354         if (mapping_iter == 1) {
355                 /*
356                  * update direct mapping page count only in the first
357                  * iteration.
358                  */
359                 update_page_count(PG_LEVEL_2M, pages_2m);
360                 update_page_count(PG_LEVEL_4K, pages_4k);
361
362                 /*
363                  * local global flush tlb, which will flush the previous
364                  * mappings present in both small and large page TLB's.
365                  */
366                 __flush_tlb_all();
367
368                 /*
369                  * Second iteration will set the actual desired PTE attributes.
370                  */
371                 mapping_iter = 2;
372                 goto repeat;
373         }
374         return last_map_addr;
375 }
376
377 pte_t *kmap_pte;
378 pgprot_t kmap_prot;
379
380 static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr)
381 {
382         return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
383                         vaddr), vaddr), vaddr);
384 }
385
386 static void __init kmap_init(void)
387 {
388         unsigned long kmap_vstart;
389
390         /*
391          * Cache the first kmap pte:
392          */
393         kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
394         kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
395
396         kmap_prot = PAGE_KERNEL;
397 }
398
399 #ifdef CONFIG_HIGHMEM
400 static void __init permanent_kmaps_init(pgd_t *pgd_base)
401 {
402         unsigned long vaddr;
403         pgd_t *pgd;
404         pud_t *pud;
405         pmd_t *pmd;
406         pte_t *pte;
407
408         vaddr = PKMAP_BASE;
409         page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
410
411         pgd = swapper_pg_dir + pgd_index(vaddr);
412         pud = pud_offset(pgd, vaddr);
413         pmd = pmd_offset(pud, vaddr);
414         pte = pte_offset_kernel(pmd, vaddr);
415         pkmap_page_table = pte;
416 }
417
418 static void __init add_one_highpage_init(struct page *page)
419 {
420         ClearPageReserved(page);
421         init_page_count(page);
422         __free_page(page);
423         totalhigh_pages++;
424 }
425
426 struct add_highpages_data {
427         unsigned long start_pfn;
428         unsigned long end_pfn;
429 };
430
431 static int __init add_highpages_work_fn(unsigned long start_pfn,
432                                          unsigned long end_pfn, void *datax)
433 {
434         int node_pfn;
435         struct page *page;
436         unsigned long final_start_pfn, final_end_pfn;
437         struct add_highpages_data *data;
438
439         data = (struct add_highpages_data *)datax;
440
441         final_start_pfn = max(start_pfn, data->start_pfn);
442         final_end_pfn = min(end_pfn, data->end_pfn);
443         if (final_start_pfn >= final_end_pfn)
444                 return 0;
445
446         for (node_pfn = final_start_pfn; node_pfn < final_end_pfn;
447              node_pfn++) {
448                 if (!pfn_valid(node_pfn))
449                         continue;
450                 page = pfn_to_page(node_pfn);
451                 add_one_highpage_init(page);
452         }
453
454         return 0;
455
456 }
457
458 void __init add_highpages_with_active_regions(int nid, unsigned long start_pfn,
459                                               unsigned long end_pfn)
460 {
461         struct add_highpages_data data;
462
463         data.start_pfn = start_pfn;
464         data.end_pfn = end_pfn;
465
466         work_with_active_regions(nid, add_highpages_work_fn, &data);
467 }
468
469 #else
470 static inline void permanent_kmaps_init(pgd_t *pgd_base)
471 {
472 }
473 #endif /* CONFIG_HIGHMEM */
474
475 void __init native_pagetable_setup_start(pgd_t *base)
476 {
477         unsigned long pfn, va;
478         pgd_t *pgd;
479         pud_t *pud;
480         pmd_t *pmd;
481         pte_t *pte;
482
483         /*
484          * Remove any mappings which extend past the end of physical
485          * memory from the boot time page table:
486          */
487         for (pfn = max_low_pfn + 1; pfn < 1<<(32-PAGE_SHIFT); pfn++) {
488                 va = PAGE_OFFSET + (pfn<<PAGE_SHIFT);
489                 pgd = base + pgd_index(va);
490                 if (!pgd_present(*pgd))
491                         break;
492
493                 pud = pud_offset(pgd, va);
494                 pmd = pmd_offset(pud, va);
495                 if (!pmd_present(*pmd))
496                         break;
497
498                 pte = pte_offset_kernel(pmd, va);
499                 if (!pte_present(*pte))
500                         break;
501
502                 pte_clear(NULL, va, pte);
503         }
504         paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT);
505 }
506
507 void __init native_pagetable_setup_done(pgd_t *base)
508 {
509 }
510
511 /*
512  * Build a proper pagetable for the kernel mappings.  Up until this
513  * point, we've been running on some set of pagetables constructed by
514  * the boot process.
515  *
516  * If we're booting on native hardware, this will be a pagetable
517  * constructed in arch/x86/kernel/head_32.S.  The root of the
518  * pagetable will be swapper_pg_dir.
519  *
520  * If we're booting paravirtualized under a hypervisor, then there are
521  * more options: we may already be running PAE, and the pagetable may
522  * or may not be based in swapper_pg_dir.  In any case,
523  * paravirt_pagetable_setup_start() will set up swapper_pg_dir
524  * appropriately for the rest of the initialization to work.
525  *
526  * In general, pagetable_init() assumes that the pagetable may already
527  * be partially populated, and so it avoids stomping on any existing
528  * mappings.
529  */
530 void __init early_ioremap_page_table_range_init(void)
531 {
532         pgd_t *pgd_base = swapper_pg_dir;
533         unsigned long vaddr, end;
534
535         /*
536          * Fixed mappings, only the page table structure has to be
537          * created - mappings will be set by set_fixmap():
538          */
539         vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
540         end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
541         page_table_range_init(vaddr, end, pgd_base);
542         early_ioremap_reset();
543 }
544
545 static void __init pagetable_init(void)
546 {
547         pgd_t *pgd_base = swapper_pg_dir;
548
549         permanent_kmaps_init(pgd_base);
550 }
551
552 #ifdef CONFIG_ACPI_SLEEP
553 /*
554  * ACPI suspend needs this for resume, because things like the intel-agp
555  * driver might have split up a kernel 4MB mapping.
556  */
557 char swsusp_pg_dir[PAGE_SIZE]
558         __attribute__ ((aligned(PAGE_SIZE)));
559
560 static inline void save_pg_dir(void)
561 {
562         memcpy(swsusp_pg_dir, swapper_pg_dir, PAGE_SIZE);
563 }
564 #else /* !CONFIG_ACPI_SLEEP */
565 static inline void save_pg_dir(void)
566 {
567 }
568 #endif /* !CONFIG_ACPI_SLEEP */
569
570 void zap_low_mappings(bool early)
571 {
572         int i;
573
574         /*
575          * Zap initial low-memory mappings.
576          *
577          * Note that "pgd_clear()" doesn't do it for
578          * us, because pgd_clear() is a no-op on i386.
579          */
580         for (i = 0; i < KERNEL_PGD_BOUNDARY; i++) {
581 #ifdef CONFIG_X86_PAE
582                 set_pgd(swapper_pg_dir+i, __pgd(1 + __pa(empty_zero_page)));
583 #else
584                 set_pgd(swapper_pg_dir+i, __pgd(0));
585 #endif
586         }
587
588         if (early)
589                 __flush_tlb();
590         else
591                 flush_tlb_all();
592 }
593
594 pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL | _PAGE_IOMAP);
595 EXPORT_SYMBOL_GPL(__supported_pte_mask);
596
597 /* user-defined highmem size */
598 static unsigned int highmem_pages = -1;
599
600 /*
601  * highmem=size forces highmem to be exactly 'size' bytes.
602  * This works even on boxes that have no highmem otherwise.
603  * This also works to reduce highmem size on bigger boxes.
604  */
605 static int __init parse_highmem(char *arg)
606 {
607         if (!arg)
608                 return -EINVAL;
609
610         highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT;
611         return 0;
612 }
613 early_param("highmem", parse_highmem);
614
615 #define MSG_HIGHMEM_TOO_BIG \
616         "highmem size (%luMB) is bigger than pages available (%luMB)!\n"
617
618 #define MSG_LOWMEM_TOO_SMALL \
619         "highmem size (%luMB) results in <64MB lowmem, ignoring it!\n"
620 /*
621  * All of RAM fits into lowmem - but if user wants highmem
622  * artificially via the highmem=x boot parameter then create
623  * it:
624  */
625 void __init lowmem_pfn_init(void)
626 {
627         /* max_low_pfn is 0, we already have early_res support */
628         max_low_pfn = max_pfn;
629
630         if (highmem_pages == -1)
631                 highmem_pages = 0;
632 #ifdef CONFIG_HIGHMEM
633         if (highmem_pages >= max_pfn) {
634                 printk(KERN_ERR MSG_HIGHMEM_TOO_BIG,
635                         pages_to_mb(highmem_pages), pages_to_mb(max_pfn));
636                 highmem_pages = 0;
637         }
638         if (highmem_pages) {
639                 if (max_low_pfn - highmem_pages < 64*1024*1024/PAGE_SIZE) {
640                         printk(KERN_ERR MSG_LOWMEM_TOO_SMALL,
641                                 pages_to_mb(highmem_pages));
642                         highmem_pages = 0;
643                 }
644                 max_low_pfn -= highmem_pages;
645         }
646 #else
647         if (highmem_pages)
648                 printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n");
649 #endif
650 }
651
652 #define MSG_HIGHMEM_TOO_SMALL \
653         "only %luMB highmem pages available, ignoring highmem size of %luMB!\n"
654
655 #define MSG_HIGHMEM_TRIMMED \
656         "Warning: only 4GB will be used. Use a HIGHMEM64G enabled kernel!\n"
657 /*
658  * We have more RAM than fits into lowmem - we try to put it into
659  * highmem, also taking the highmem=x boot parameter into account:
660  */
661 void __init highmem_pfn_init(void)
662 {
663         max_low_pfn = MAXMEM_PFN;
664
665         if (highmem_pages == -1)
666                 highmem_pages = max_pfn - MAXMEM_PFN;
667
668         if (highmem_pages + MAXMEM_PFN < max_pfn)
669                 max_pfn = MAXMEM_PFN + highmem_pages;
670
671         if (highmem_pages + MAXMEM_PFN > max_pfn) {
672                 printk(KERN_WARNING MSG_HIGHMEM_TOO_SMALL,
673                         pages_to_mb(max_pfn - MAXMEM_PFN),
674                         pages_to_mb(highmem_pages));
675                 highmem_pages = 0;
676         }
677 #ifndef CONFIG_HIGHMEM
678         /* Maximum memory usable is what is directly addressable */
679         printk(KERN_WARNING "Warning only %ldMB will be used.\n", MAXMEM>>20);
680         if (max_pfn > MAX_NONPAE_PFN)
681                 printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n");
682         else
683                 printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");
684         max_pfn = MAXMEM_PFN;
685 #else /* !CONFIG_HIGHMEM */
686 #ifndef CONFIG_HIGHMEM64G
687         if (max_pfn > MAX_NONPAE_PFN) {
688                 max_pfn = MAX_NONPAE_PFN;
689                 printk(KERN_WARNING MSG_HIGHMEM_TRIMMED);
690         }
691 #endif /* !CONFIG_HIGHMEM64G */
692 #endif /* !CONFIG_HIGHMEM */
693 }
694
695 /*
696  * Determine low and high memory ranges:
697  */
698 void __init find_low_pfn_range(void)
699 {
700         /* it could update max_pfn */
701
702         if (max_pfn <= MAXMEM_PFN)
703                 lowmem_pfn_init();
704         else
705                 highmem_pfn_init();
706 }
707
708 #ifndef CONFIG_NEED_MULTIPLE_NODES
709 void __init initmem_init(unsigned long start_pfn, unsigned long end_pfn,
710                                 int acpi, int k8)
711 {
712 #ifdef CONFIG_HIGHMEM
713         highstart_pfn = highend_pfn = max_pfn;
714         if (max_pfn > max_low_pfn)
715                 highstart_pfn = max_low_pfn;
716         memblock_x86_register_active_regions(0, 0, highend_pfn);
717         sparse_memory_present_with_active_regions(0);
718         printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
719                 pages_to_mb(highend_pfn - highstart_pfn));
720         num_physpages = highend_pfn;
721         high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1;
722 #else
723         memblock_x86_register_active_regions(0, 0, max_low_pfn);
724         sparse_memory_present_with_active_regions(0);
725         num_physpages = max_low_pfn;
726         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1;
727 #endif
728 #ifdef CONFIG_FLATMEM
729         max_mapnr = num_physpages;
730 #endif
731         __vmalloc_start_set = true;
732
733         printk(KERN_NOTICE "%ldMB LOWMEM available.\n",
734                         pages_to_mb(max_low_pfn));
735
736         setup_bootmem_allocator();
737 }
738 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
739
740 static void __init zone_sizes_init(void)
741 {
742         unsigned long max_zone_pfns[MAX_NR_ZONES];
743         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
744         max_zone_pfns[ZONE_DMA] =
745                 virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
746         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
747 #ifdef CONFIG_HIGHMEM
748         max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
749 #endif
750
751         free_area_init_nodes(max_zone_pfns);
752 }
753
754 #ifndef CONFIG_NO_BOOTMEM
755 static unsigned long __init setup_node_bootmem(int nodeid,
756                                  unsigned long start_pfn,
757                                  unsigned long end_pfn,
758                                  unsigned long bootmap)
759 {
760         unsigned long bootmap_size;
761
762         /* don't touch min_low_pfn */
763         bootmap_size = init_bootmem_node(NODE_DATA(nodeid),
764                                          bootmap >> PAGE_SHIFT,
765                                          start_pfn, end_pfn);
766         printk(KERN_INFO "  node %d low ram: %08lx - %08lx\n",
767                 nodeid, start_pfn<<PAGE_SHIFT, end_pfn<<PAGE_SHIFT);
768         printk(KERN_INFO "  node %d bootmap %08lx - %08lx\n",
769                  nodeid, bootmap, bootmap + bootmap_size);
770         free_bootmem_with_active_regions(nodeid, end_pfn);
771
772         return bootmap + bootmap_size;
773 }
774 #endif
775
776 void __init setup_bootmem_allocator(void)
777 {
778 #ifndef CONFIG_NO_BOOTMEM
779         int nodeid;
780         phys_addr_t bootmap_size, bootmap;
781         /*
782          * Initialize the boot-time allocator (with low memory only):
783          */
784         bootmap_size = bootmem_bootmap_pages(max_low_pfn)<<PAGE_SHIFT;
785         bootmap = memblock_find_in_range(0, max_pfn_mapped<<PAGE_SHIFT, bootmap_size,
786                                  PAGE_SIZE);
787         if (bootmap == MEMBLOCK_ERROR)
788                 panic("Cannot find bootmem map of size %ld\n", bootmap_size);
789         memblock_x86_reserve_range(bootmap, bootmap + bootmap_size, "BOOTMAP");
790 #endif
791
792         printk(KERN_INFO "  mapped low ram: 0 - %08lx\n",
793                  max_pfn_mapped<<PAGE_SHIFT);
794         printk(KERN_INFO "  low ram: 0 - %08lx\n", max_low_pfn<<PAGE_SHIFT);
795
796 #ifndef CONFIG_NO_BOOTMEM
797         for_each_online_node(nodeid) {
798                  unsigned long start_pfn, end_pfn;
799
800 #ifdef CONFIG_NEED_MULTIPLE_NODES
801                 start_pfn = node_start_pfn[nodeid];
802                 end_pfn = node_end_pfn[nodeid];
803                 if (start_pfn > max_low_pfn)
804                         continue;
805                 if (end_pfn > max_low_pfn)
806                         end_pfn = max_low_pfn;
807 #else
808                 start_pfn = 0;
809                 end_pfn = max_low_pfn;
810 #endif
811                 bootmap = setup_node_bootmem(nodeid, start_pfn, end_pfn,
812                                                  bootmap);
813         }
814 #endif
815
816         after_bootmem = 1;
817 }
818
819 /*
820  * paging_init() sets up the page tables - note that the first 8MB are
821  * already mapped by head.S.
822  *
823  * This routines also unmaps the page at virtual kernel address 0, so
824  * that we can trap those pesky NULL-reference errors in the kernel.
825  */
826 void __init paging_init(void)
827 {
828         pagetable_init();
829
830         __flush_tlb_all();
831
832         kmap_init();
833
834         /*
835          * NOTE: at this point the bootmem allocator is fully available.
836          */
837         sparse_init();
838         zone_sizes_init();
839 }
840
841 /*
842  * Test if the WP bit works in supervisor mode. It isn't supported on 386's
843  * and also on some strange 486's. All 586+'s are OK. This used to involve
844  * black magic jumps to work around some nasty CPU bugs, but fortunately the
845  * switch to using exceptions got rid of all that.
846  */
847 static void __init test_wp_bit(void)
848 {
849         printk(KERN_INFO
850   "Checking if this processor honours the WP bit even in supervisor mode...");
851
852         /* Any page-aligned address will do, the test is non-destructive */
853         __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_READONLY);
854         boot_cpu_data.wp_works_ok = do_test_wp_bit();
855         clear_fixmap(FIX_WP_TEST);
856
857         if (!boot_cpu_data.wp_works_ok) {
858                 printk(KERN_CONT "No.\n");
859 #ifdef CONFIG_X86_WP_WORKS_OK
860                 panic(
861   "This kernel doesn't support CPU's with broken WP. Recompile it for a 386!");
862 #endif
863         } else {
864                 printk(KERN_CONT "Ok.\n");
865         }
866 }
867
868 void __init mem_init(void)
869 {
870         int codesize, reservedpages, datasize, initsize;
871         int tmp;
872
873         pci_iommu_alloc();
874
875 #ifdef CONFIG_FLATMEM
876         BUG_ON(!mem_map);
877 #endif
878         /* this will put all low memory onto the freelists */
879         totalram_pages += free_all_bootmem();
880
881         reservedpages = 0;
882         for (tmp = 0; tmp < max_low_pfn; tmp++)
883                 /*
884                  * Only count reserved RAM pages:
885                  */
886                 if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp)))
887                         reservedpages++;
888
889         set_highmem_pages_init();
890
891         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
892         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
893         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
894
895         printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
896                         "%dk reserved, %dk data, %dk init, %ldk highmem)\n",
897                 nr_free_pages() << (PAGE_SHIFT-10),
898                 num_physpages << (PAGE_SHIFT-10),
899                 codesize >> 10,
900                 reservedpages << (PAGE_SHIFT-10),
901                 datasize >> 10,
902                 initsize >> 10,
903                 totalhigh_pages << (PAGE_SHIFT-10));
904
905         printk(KERN_INFO "virtual kernel memory layout:\n"
906                 "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
907 #ifdef CONFIG_HIGHMEM
908                 "    pkmap   : 0x%08lx - 0x%08lx   (%4ld kB)\n"
909 #endif
910                 "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
911                 "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
912                 "      .init : 0x%08lx - 0x%08lx   (%4ld kB)\n"
913                 "      .data : 0x%08lx - 0x%08lx   (%4ld kB)\n"
914                 "      .text : 0x%08lx - 0x%08lx   (%4ld kB)\n",
915                 FIXADDR_START, FIXADDR_TOP,
916                 (FIXADDR_TOP - FIXADDR_START) >> 10,
917
918 #ifdef CONFIG_HIGHMEM
919                 PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
920                 (LAST_PKMAP*PAGE_SIZE) >> 10,
921 #endif
922
923                 VMALLOC_START, VMALLOC_END,
924                 (VMALLOC_END - VMALLOC_START) >> 20,
925
926                 (unsigned long)__va(0), (unsigned long)high_memory,
927                 ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
928
929                 (unsigned long)&__init_begin, (unsigned long)&__init_end,
930                 ((unsigned long)&__init_end -
931                  (unsigned long)&__init_begin) >> 10,
932
933                 (unsigned long)&_etext, (unsigned long)&_edata,
934                 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
935
936                 (unsigned long)&_text, (unsigned long)&_etext,
937                 ((unsigned long)&_etext - (unsigned long)&_text) >> 10);
938
939         /*
940          * Check boundaries twice: Some fundamental inconsistencies can
941          * be detected at build time already.
942          */
943 #define __FIXADDR_TOP (-PAGE_SIZE)
944 #ifdef CONFIG_HIGHMEM
945         BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE  > FIXADDR_START);
946         BUILD_BUG_ON(VMALLOC_END                        > PKMAP_BASE);
947 #endif
948 #define high_memory (-128UL << 20)
949         BUILD_BUG_ON(VMALLOC_START                      >= VMALLOC_END);
950 #undef high_memory
951 #undef __FIXADDR_TOP
952
953 #ifdef CONFIG_HIGHMEM
954         BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE        > FIXADDR_START);
955         BUG_ON(VMALLOC_END                              > PKMAP_BASE);
956 #endif
957         BUG_ON(VMALLOC_START                            >= VMALLOC_END);
958         BUG_ON((unsigned long)high_memory               > VMALLOC_START);
959
960         if (boot_cpu_data.wp_works_ok < 0)
961                 test_wp_bit();
962
963         save_pg_dir();
964         zap_low_mappings(true);
965 }
966
967 #ifdef CONFIG_MEMORY_HOTPLUG
968 int arch_add_memory(int nid, u64 start, u64 size)
969 {
970         struct pglist_data *pgdata = NODE_DATA(nid);
971         struct zone *zone = pgdata->node_zones + ZONE_HIGHMEM;
972         unsigned long start_pfn = start >> PAGE_SHIFT;
973         unsigned long nr_pages = size >> PAGE_SHIFT;
974
975         return __add_pages(nid, zone, start_pfn, nr_pages);
976 }
977 #endif
978
979 /*
980  * This function cannot be __init, since exceptions don't work in that
981  * section.  Put this after the callers, so that it cannot be inlined.
982  */
983 static noinline int do_test_wp_bit(void)
984 {
985         char tmp_reg;
986         int flag;
987
988         __asm__ __volatile__(
989                 "       movb %0, %1     \n"
990                 "1:     movb %1, %0     \n"
991                 "       xorl %2, %2     \n"
992                 "2:                     \n"
993                 _ASM_EXTABLE(1b,2b)
994                 :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)),
995                  "=q" (tmp_reg),
996                  "=r" (flag)
997                 :"2" (1)
998                 :"memory");
999
1000         return flag;
1001 }
1002
1003 #ifdef CONFIG_DEBUG_RODATA
1004 const int rodata_test_data = 0xC3;
1005 EXPORT_SYMBOL_GPL(rodata_test_data);
1006
1007 int kernel_set_to_readonly __read_mostly;
1008
1009 void set_kernel_text_rw(void)
1010 {
1011         unsigned long start = PFN_ALIGN(_text);
1012         unsigned long size = PFN_ALIGN(_etext) - start;
1013
1014         if (!kernel_set_to_readonly)
1015                 return;
1016
1017         pr_debug("Set kernel text: %lx - %lx for read write\n",
1018                  start, start+size);
1019
1020         set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
1021 }
1022
1023 void set_kernel_text_ro(void)
1024 {
1025         unsigned long start = PFN_ALIGN(_text);
1026         unsigned long size = PFN_ALIGN(_etext) - start;
1027
1028         if (!kernel_set_to_readonly)
1029                 return;
1030
1031         pr_debug("Set kernel text: %lx - %lx for read only\n",
1032                  start, start+size);
1033
1034         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
1035 }
1036
1037 void mark_rodata_ro(void)
1038 {
1039         unsigned long start = PFN_ALIGN(_text);
1040         unsigned long size = PFN_ALIGN(_etext) - start;
1041
1042         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
1043         printk(KERN_INFO "Write protecting the kernel text: %luk\n",
1044                 size >> 10);
1045
1046         kernel_set_to_readonly = 1;
1047
1048 #ifdef CONFIG_CPA_DEBUG
1049         printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n",
1050                 start, start+size);
1051         set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT);
1052
1053         printk(KERN_INFO "Testing CPA: write protecting again\n");
1054         set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT);
1055 #endif
1056
1057         start += size;
1058         size = (unsigned long)__end_rodata - start;
1059         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
1060         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
1061                 size >> 10);
1062         rodata_test();
1063
1064 #ifdef CONFIG_CPA_DEBUG
1065         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size);
1066         set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
1067
1068         printk(KERN_INFO "Testing CPA: write protecting again\n");
1069         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
1070 #endif
1071 }
1072 #endif
1073