x86: Remove old bootmem code
[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 void __init setup_bootmem_allocator(void)
755 {
756         printk(KERN_INFO "  mapped low ram: 0 - %08lx\n",
757                  max_pfn_mapped<<PAGE_SHIFT);
758         printk(KERN_INFO "  low ram: 0 - %08lx\n", max_low_pfn<<PAGE_SHIFT);
759
760         after_bootmem = 1;
761 }
762
763 /*
764  * paging_init() sets up the page tables - note that the first 8MB are
765  * already mapped by head.S.
766  *
767  * This routines also unmaps the page at virtual kernel address 0, so
768  * that we can trap those pesky NULL-reference errors in the kernel.
769  */
770 void __init paging_init(void)
771 {
772         pagetable_init();
773
774         __flush_tlb_all();
775
776         kmap_init();
777
778         /*
779          * NOTE: at this point the bootmem allocator is fully available.
780          */
781         sparse_init();
782         zone_sizes_init();
783 }
784
785 /*
786  * Test if the WP bit works in supervisor mode. It isn't supported on 386's
787  * and also on some strange 486's. All 586+'s are OK. This used to involve
788  * black magic jumps to work around some nasty CPU bugs, but fortunately the
789  * switch to using exceptions got rid of all that.
790  */
791 static void __init test_wp_bit(void)
792 {
793         printk(KERN_INFO
794   "Checking if this processor honours the WP bit even in supervisor mode...");
795
796         /* Any page-aligned address will do, the test is non-destructive */
797         __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_READONLY);
798         boot_cpu_data.wp_works_ok = do_test_wp_bit();
799         clear_fixmap(FIX_WP_TEST);
800
801         if (!boot_cpu_data.wp_works_ok) {
802                 printk(KERN_CONT "No.\n");
803 #ifdef CONFIG_X86_WP_WORKS_OK
804                 panic(
805   "This kernel doesn't support CPU's with broken WP. Recompile it for a 386!");
806 #endif
807         } else {
808                 printk(KERN_CONT "Ok.\n");
809         }
810 }
811
812 void __init mem_init(void)
813 {
814         int codesize, reservedpages, datasize, initsize;
815         int tmp;
816
817         pci_iommu_alloc();
818
819 #ifdef CONFIG_FLATMEM
820         BUG_ON(!mem_map);
821 #endif
822         /* this will put all low memory onto the freelists */
823         totalram_pages += free_all_bootmem();
824
825         reservedpages = 0;
826         for (tmp = 0; tmp < max_low_pfn; tmp++)
827                 /*
828                  * Only count reserved RAM pages:
829                  */
830                 if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp)))
831                         reservedpages++;
832
833         set_highmem_pages_init();
834
835         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
836         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
837         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
838
839         printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
840                         "%dk reserved, %dk data, %dk init, %ldk highmem)\n",
841                 nr_free_pages() << (PAGE_SHIFT-10),
842                 num_physpages << (PAGE_SHIFT-10),
843                 codesize >> 10,
844                 reservedpages << (PAGE_SHIFT-10),
845                 datasize >> 10,
846                 initsize >> 10,
847                 totalhigh_pages << (PAGE_SHIFT-10));
848
849         printk(KERN_INFO "virtual kernel memory layout:\n"
850                 "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
851 #ifdef CONFIG_HIGHMEM
852                 "    pkmap   : 0x%08lx - 0x%08lx   (%4ld kB)\n"
853 #endif
854                 "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
855                 "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
856                 "      .init : 0x%08lx - 0x%08lx   (%4ld kB)\n"
857                 "      .data : 0x%08lx - 0x%08lx   (%4ld kB)\n"
858                 "      .text : 0x%08lx - 0x%08lx   (%4ld kB)\n",
859                 FIXADDR_START, FIXADDR_TOP,
860                 (FIXADDR_TOP - FIXADDR_START) >> 10,
861
862 #ifdef CONFIG_HIGHMEM
863                 PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
864                 (LAST_PKMAP*PAGE_SIZE) >> 10,
865 #endif
866
867                 VMALLOC_START, VMALLOC_END,
868                 (VMALLOC_END - VMALLOC_START) >> 20,
869
870                 (unsigned long)__va(0), (unsigned long)high_memory,
871                 ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
872
873                 (unsigned long)&__init_begin, (unsigned long)&__init_end,
874                 ((unsigned long)&__init_end -
875                  (unsigned long)&__init_begin) >> 10,
876
877                 (unsigned long)&_etext, (unsigned long)&_edata,
878                 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
879
880                 (unsigned long)&_text, (unsigned long)&_etext,
881                 ((unsigned long)&_etext - (unsigned long)&_text) >> 10);
882
883         /*
884          * Check boundaries twice: Some fundamental inconsistencies can
885          * be detected at build time already.
886          */
887 #define __FIXADDR_TOP (-PAGE_SIZE)
888 #ifdef CONFIG_HIGHMEM
889         BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE  > FIXADDR_START);
890         BUILD_BUG_ON(VMALLOC_END                        > PKMAP_BASE);
891 #endif
892 #define high_memory (-128UL << 20)
893         BUILD_BUG_ON(VMALLOC_START                      >= VMALLOC_END);
894 #undef high_memory
895 #undef __FIXADDR_TOP
896
897 #ifdef CONFIG_HIGHMEM
898         BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE        > FIXADDR_START);
899         BUG_ON(VMALLOC_END                              > PKMAP_BASE);
900 #endif
901         BUG_ON(VMALLOC_START                            >= VMALLOC_END);
902         BUG_ON((unsigned long)high_memory               > VMALLOC_START);
903
904         if (boot_cpu_data.wp_works_ok < 0)
905                 test_wp_bit();
906
907         save_pg_dir();
908         zap_low_mappings(true);
909 }
910
911 #ifdef CONFIG_MEMORY_HOTPLUG
912 int arch_add_memory(int nid, u64 start, u64 size)
913 {
914         struct pglist_data *pgdata = NODE_DATA(nid);
915         struct zone *zone = pgdata->node_zones + ZONE_HIGHMEM;
916         unsigned long start_pfn = start >> PAGE_SHIFT;
917         unsigned long nr_pages = size >> PAGE_SHIFT;
918
919         return __add_pages(nid, zone, start_pfn, nr_pages);
920 }
921 #endif
922
923 /*
924  * This function cannot be __init, since exceptions don't work in that
925  * section.  Put this after the callers, so that it cannot be inlined.
926  */
927 static noinline int do_test_wp_bit(void)
928 {
929         char tmp_reg;
930         int flag;
931
932         __asm__ __volatile__(
933                 "       movb %0, %1     \n"
934                 "1:     movb %1, %0     \n"
935                 "       xorl %2, %2     \n"
936                 "2:                     \n"
937                 _ASM_EXTABLE(1b,2b)
938                 :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)),
939                  "=q" (tmp_reg),
940                  "=r" (flag)
941                 :"2" (1)
942                 :"memory");
943
944         return flag;
945 }
946
947 #ifdef CONFIG_DEBUG_RODATA
948 const int rodata_test_data = 0xC3;
949 EXPORT_SYMBOL_GPL(rodata_test_data);
950
951 int kernel_set_to_readonly __read_mostly;
952
953 void set_kernel_text_rw(void)
954 {
955         unsigned long start = PFN_ALIGN(_text);
956         unsigned long size = PFN_ALIGN(_etext) - start;
957
958         if (!kernel_set_to_readonly)
959                 return;
960
961         pr_debug("Set kernel text: %lx - %lx for read write\n",
962                  start, start+size);
963
964         set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
965 }
966
967 void set_kernel_text_ro(void)
968 {
969         unsigned long start = PFN_ALIGN(_text);
970         unsigned long size = PFN_ALIGN(_etext) - start;
971
972         if (!kernel_set_to_readonly)
973                 return;
974
975         pr_debug("Set kernel text: %lx - %lx for read only\n",
976                  start, start+size);
977
978         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
979 }
980
981 void mark_rodata_ro(void)
982 {
983         unsigned long start = PFN_ALIGN(_text);
984         unsigned long size = PFN_ALIGN(_etext) - start;
985
986         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
987         printk(KERN_INFO "Write protecting the kernel text: %luk\n",
988                 size >> 10);
989
990         kernel_set_to_readonly = 1;
991
992 #ifdef CONFIG_CPA_DEBUG
993         printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n",
994                 start, start+size);
995         set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT);
996
997         printk(KERN_INFO "Testing CPA: write protecting again\n");
998         set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT);
999 #endif
1000
1001         start += size;
1002         size = (unsigned long)__end_rodata - start;
1003         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
1004         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
1005                 size >> 10);
1006         rodata_test();
1007
1008 #ifdef CONFIG_CPA_DEBUG
1009         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size);
1010         set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
1011
1012         printk(KERN_INFO "Testing CPA: write protecting again\n");
1013         set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
1014 #endif
1015 }
1016 #endif
1017