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/signal.h>
9 #include <linux/sched.h>
10 #include <linux/kernel.h>
11 #include <linux/errno.h>
12 #include <linux/string.h>
13 #include <linux/types.h>
14 #include <linux/ptrace.h>
15 #include <linux/mman.h>
16 #include <linux/mm.h>
17 #include <linux/hugetlb.h>
18 #include <linux/swap.h>
19 #include <linux/smp.h>
20 #include <linux/init.h>
21 #include <linux/highmem.h>
22 #include <linux/pagemap.h>
23 #include <linux/pci.h>
24 #include <linux/pfn.h>
25 #include <linux/poison.h>
26 #include <linux/bootmem.h>
27 #include <linux/memblock.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 <linux/uaccess.h>
38 #include <asm/pgtable.h>
39 #include <asm/dma.h>
40 #include <asm/fixmap.h>
41 #include <asm/e820.h>
42 #include <asm/apic.h>
43 #include <asm/bugs.h>
44 #include <asm/tlb.h>
45 #include <asm/tlbflush.h>
46 #include <asm/olpc_ofw.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 #include "mm_internal.h"
56
57 unsigned long highstart_pfn, highend_pfn;
58
59 static noinline int do_test_wp_bit(void);
60
61 bool __read_mostly __vmalloc_start_set = false;
62
63 /*
64 * Creates a middle page table and puts a pointer to it in the
65 * given global directory entry. This only returns the gd entry
66 * in non-PAE compilation mode, since the middle layer is folded.
67 */
68 static pmd_t * __init one_md_table_init(pgd_t *pgd)
69 {
70 pud_t *pud;
71 pmd_t *pmd_table;
72
73 #ifdef CONFIG_X86_PAE
74 if (!(pgd_val(*pgd) & _PAGE_PRESENT)) {
75 pmd_table = (pmd_t *)alloc_low_page();
76 paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT);
77 set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
78 pud = pud_offset(pgd, 0);
79 BUG_ON(pmd_table != pmd_offset(pud, 0));
80
81 return pmd_table;
82 }
83 #endif
84 pud = pud_offset(pgd, 0);
85 pmd_table = pmd_offset(pud, 0);
86
87 return pmd_table;
88 }
89
90 /*
91 * Create a page table and place a pointer to it in a middle page
92 * directory entry:
93 */
94 static pte_t * __init one_page_table_init(pmd_t *pmd)
95 {
96 if (!(pmd_val(*pmd) & _PAGE_PRESENT)) {
97 pte_t *page_table = (pte_t *)alloc_low_page();
98
99 paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT);
100 set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE));
101 BUG_ON(page_table != pte_offset_kernel(pmd, 0));
102 }
103
104 return pte_offset_kernel(pmd, 0);
105 }
106
107 pmd_t * __init populate_extra_pmd(unsigned long vaddr)
108 {
109 int pgd_idx = pgd_index(vaddr);
110 int pmd_idx = pmd_index(vaddr);
111
112 return one_md_table_init(swapper_pg_dir + pgd_idx) + pmd_idx;
113 }
114
115 pte_t * __init populate_extra_pte(unsigned long vaddr)
116 {
117 int pte_idx = pte_index(vaddr);
118 pmd_t *pmd;
119
120 pmd = populate_extra_pmd(vaddr);
121 return one_page_table_init(pmd) + pte_idx;
122 }
123
124 static unsigned long __init
125 page_table_range_init_count(unsigned long start, unsigned long end)
126 {
127 unsigned long count = 0;
128 #ifdef CONFIG_HIGHMEM
129 int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT;
130 int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT;
131 int pgd_idx, pmd_idx;
132 unsigned long vaddr;
133
134 if (pmd_idx_kmap_begin == pmd_idx_kmap_end)
135 return 0;
136
137 vaddr = start;
138 pgd_idx = pgd_index(vaddr);
139 pmd_idx = pmd_index(vaddr);
140
141 for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd_idx++) {
142 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);
143 pmd_idx++) {
144 if ((vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin &&
145 (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end)
146 count++;
147 vaddr += PMD_SIZE;
148 }
149 pmd_idx = 0;
150 }
151 #endif
152 return count;
153 }
154
155 static pte_t *__init page_table_kmap_check(pte_t *pte, pmd_t *pmd,
156 unsigned long vaddr, pte_t *lastpte,
157 void **adr)
158 {
159 #ifdef CONFIG_HIGHMEM
160 /*
161 * Something (early fixmap) may already have put a pte
162 * page here, which causes the page table allocation
163 * to become nonlinear. Attempt to fix it, and if it
164 * is still nonlinear then we have to bug.
165 */
166 int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT;
167 int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT;
168
169 if (pmd_idx_kmap_begin != pmd_idx_kmap_end
170 && (vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin
171 && (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end) {
172 pte_t *newpte;
173 int i;
174
175 BUG_ON(after_bootmem);
176 newpte = *adr;
177 for (i = 0; i < PTRS_PER_PTE; i++)
178 set_pte(newpte + i, pte[i]);
179 *adr = (void *)(((unsigned long)(*adr)) + PAGE_SIZE);
180
181 paravirt_alloc_pte(&init_mm, __pa(newpte) >> PAGE_SHIFT);
182 set_pmd(pmd, __pmd(__pa(newpte)|_PAGE_TABLE));
183 BUG_ON(newpte != pte_offset_kernel(pmd, 0));
184 __flush_tlb_all();
185
186 paravirt_release_pte(__pa(pte) >> PAGE_SHIFT);
187 pte = newpte;
188 }
189 BUG_ON(vaddr < fix_to_virt(FIX_KMAP_BEGIN - 1)
190 && vaddr > fix_to_virt(FIX_KMAP_END)
191 && lastpte && lastpte + PTRS_PER_PTE != pte);
192 #endif
193 return pte;
194 }
195
196 /*
197 * This function initializes a certain range of kernel virtual memory
198 * with new bootmem page tables, everywhere page tables are missing in
199 * the given range.
200 *
201 * NOTE: The pagetables are allocated contiguous on the physical space
202 * so we can cache the place of the first one and move around without
203 * checking the pgd every time.
204 */
205 static void __init
206 page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base)
207 {
208 int pgd_idx, pmd_idx;
209 unsigned long vaddr;
210 pgd_t *pgd;
211 pmd_t *pmd;
212 pte_t *pte = NULL;
213 unsigned long count = page_table_range_init_count(start, end);
214 void *adr = NULL;
215
216 if (count)
217 adr = alloc_low_pages(count);
218
219 vaddr = start;
220 pgd_idx = pgd_index(vaddr);
221 pmd_idx = pmd_index(vaddr);
222 pgd = pgd_base + pgd_idx;
223
224 for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
225 pmd = one_md_table_init(pgd);
226 pmd = pmd + pmd_index(vaddr);
227 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);
228 pmd++, pmd_idx++) {
229 pte = page_table_kmap_check(one_page_table_init(pmd),
230 pmd, vaddr, pte, &adr);
231
232 vaddr += PMD_SIZE;
233 }
234 pmd_idx = 0;
235 }
236 }
237
238 static inline int is_kernel_text(unsigned long addr)
239 {
240 if (addr >= (unsigned long)_text && addr <= (unsigned long)__init_end)
241 return 1;
242 return 0;
243 }
244
245 /*
246 * This maps the physical memory to kernel virtual address space, a total
247 * of max_low_pfn pages, by creating page tables starting from address
248 * PAGE_OFFSET:
249 */
250 unsigned long __init
251 kernel_physical_mapping_init(unsigned long start,
252 unsigned long end,
253 unsigned long page_size_mask)
254 {
255 int use_pse = page_size_mask == (1<<PG_LEVEL_2M);
256 unsigned long last_map_addr = end;
257 unsigned long start_pfn, end_pfn;
258 pgd_t *pgd_base = swapper_pg_dir;
259 int pgd_idx, pmd_idx, pte_ofs;
260 unsigned long pfn;
261 pgd_t *pgd;
262 pmd_t *pmd;
263 pte_t *pte;
264 unsigned pages_2m, pages_4k;
265 int mapping_iter;
266
267 start_pfn = start >> PAGE_SHIFT;
268 end_pfn = end >> PAGE_SHIFT;
269
270 /*
271 * First iteration will setup identity mapping using large/small pages
272 * based on use_pse, with other attributes same as set by
273 * the early code in head_32.S
274 *
275 * Second iteration will setup the appropriate attributes (NX, GLOBAL..)
276 * as desired for the kernel identity mapping.
277 *
278 * This two pass mechanism conforms to the TLB app note which says:
279 *
280 * "Software should not write to a paging-structure entry in a way
281 * that would change, for any linear address, both the page size
282 * and either the page frame or attributes."
283 */
284 mapping_iter = 1;
285
286 if (!boot_cpu_has(X86_FEATURE_PSE))
287 use_pse = 0;
288
289 repeat:
290 pages_2m = pages_4k = 0;
291 pfn = start_pfn;
292 pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
293 pgd = pgd_base + pgd_idx;
294 for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) {
295 pmd = one_md_table_init(pgd);
296
297 if (pfn >= end_pfn)
298 continue;
299 #ifdef CONFIG_X86_PAE
300 pmd_idx = pmd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
301 pmd += pmd_idx;
302 #else
303 pmd_idx = 0;
304 #endif
305 for (; pmd_idx < PTRS_PER_PMD && pfn < end_pfn;
306 pmd++, pmd_idx++) {
307 unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET;
308
309 /*
310 * Map with big pages if possible, otherwise
311 * create normal page tables:
312 */
313 if (use_pse) {
314 unsigned int addr2;
315 pgprot_t prot = PAGE_KERNEL_LARGE;
316 /*
317 * first pass will use the same initial
318 * identity mapping attribute + _PAGE_PSE.
319 */
320 pgprot_t init_prot =
321 __pgprot(PTE_IDENT_ATTR |
322 _PAGE_PSE);
323
324 pfn &= PMD_MASK >> PAGE_SHIFT;
325 addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE +
326 PAGE_OFFSET + PAGE_SIZE-1;
327
328 if (is_kernel_text(addr) ||
329 is_kernel_text(addr2))
330 prot = PAGE_KERNEL_LARGE_EXEC;
331
332 pages_2m++;
333 if (mapping_iter == 1)
334 set_pmd(pmd, pfn_pmd(pfn, init_prot));
335 else
336 set_pmd(pmd, pfn_pmd(pfn, prot));
337
338 pfn += PTRS_PER_PTE;
339 continue;
340 }
341 pte = one_page_table_init(pmd);
342
343 pte_ofs = pte_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
344 pte += pte_ofs;
345 for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn;
346 pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) {
347 pgprot_t prot = PAGE_KERNEL;
348 /*
349 * first pass will use the same initial
350 * identity mapping attribute.
351 */
352 pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR);
353
354 if (is_kernel_text(addr))
355 prot = PAGE_KERNEL_EXEC;
356
357 pages_4k++;
358 if (mapping_iter == 1) {
359 set_pte(pte, pfn_pte(pfn, init_prot));
360 last_map_addr = (pfn << PAGE_SHIFT) + PAGE_SIZE;
361 } else
362 set_pte(pte, pfn_pte(pfn, prot));
363 }
364 }
365 }
366 if (mapping_iter == 1) {
367 /*
368 * update direct mapping page count only in the first
369 * iteration.
370 */
371 update_page_count(PG_LEVEL_2M, pages_2m);
372 update_page_count(PG_LEVEL_4K, pages_4k);
373
374 /*
375 * local global flush tlb, which will flush the previous
376 * mappings present in both small and large page TLB's.
377 */
378 __flush_tlb_all();
379
380 /*
381 * Second iteration will set the actual desired PTE attributes.
382 */
383 mapping_iter = 2;
384 goto repeat;
385 }
386 return last_map_addr;
387 }
388
389 pte_t *kmap_pte;
390
391 static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr)
392 {
393 return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
394 vaddr), vaddr), vaddr);
395 }
396
397 static void __init kmap_init(void)
398 {
399 unsigned long kmap_vstart;
400
401 /*
402 * Cache the first kmap pte:
403 */
404 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
405 kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
406 }
407
408 #ifdef CONFIG_HIGHMEM
409 static void __init permanent_kmaps_init(pgd_t *pgd_base)
410 {
411 unsigned long vaddr;
412 pgd_t *pgd;
413 pud_t *pud;
414 pmd_t *pmd;
415 pte_t *pte;
416
417 vaddr = PKMAP_BASE;
418 page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
419
420 pgd = swapper_pg_dir + pgd_index(vaddr);
421 pud = pud_offset(pgd, vaddr);
422 pmd = pmd_offset(pud, vaddr);
423 pte = pte_offset_kernel(pmd, vaddr);
424 pkmap_page_table = pte;
425 }
426
427 void __init add_highpages_with_active_regions(int nid,
428 unsigned long start_pfn, unsigned long end_pfn)
429 {
430 phys_addr_t start, end;
431 u64 i;
432
433 for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &start, &end, NULL) {
434 unsigned long pfn = clamp_t(unsigned long, PFN_UP(start),
435 start_pfn, end_pfn);
436 unsigned long e_pfn = clamp_t(unsigned long, PFN_DOWN(end),
437 start_pfn, end_pfn);
438 for ( ; pfn < e_pfn; pfn++)
439 if (pfn_valid(pfn))
440 free_highmem_page(pfn_to_page(pfn));
441 }
442 }
443 #else
444 static inline void permanent_kmaps_init(pgd_t *pgd_base)
445 {
446 }
447 #endif /* CONFIG_HIGHMEM */
448
449 void __init native_pagetable_init(void)
450 {
451 unsigned long pfn, va;
452 pgd_t *pgd, *base = swapper_pg_dir;
453 pud_t *pud;
454 pmd_t *pmd;
455 pte_t *pte;
456
457 /*
458 * Remove any mappings which extend past the end of physical
459 * memory from the boot time page table.
460 * In virtual address space, we should have at least two pages
461 * from VMALLOC_END to pkmap or fixmap according to VMALLOC_END
462 * definition. And max_low_pfn is set to VMALLOC_END physical
463 * address. If initial memory mapping is doing right job, we
464 * should have pte used near max_low_pfn or one pmd is not present.
465 */
466 for (pfn = max_low_pfn; pfn < 1<<(32-PAGE_SHIFT); pfn++) {
467 va = PAGE_OFFSET + (pfn<<PAGE_SHIFT);
468 pgd = base + pgd_index(va);
469 if (!pgd_present(*pgd))
470 break;
471
472 pud = pud_offset(pgd, va);
473 pmd = pmd_offset(pud, va);
474 if (!pmd_present(*pmd))
475 break;
476
477 /* should not be large page here */
478 if (pmd_large(*pmd)) {
479 pr_warn("try to clear pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx, but pmd is big page and is not using pte !\n",
480 pfn, pmd, __pa(pmd));
481 BUG_ON(1);
482 }
483
484 pte = pte_offset_kernel(pmd, va);
485 if (!pte_present(*pte))
486 break;
487
488 printk(KERN_DEBUG "clearing pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx pte: %p pte phys: %lx\n",
489 pfn, pmd, __pa(pmd), pte, __pa(pte));
490 pte_clear(NULL, va, pte);
491 }
492 paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT);
493 paging_init();
494 }
495
496 /*
497 * Build a proper pagetable for the kernel mappings. Up until this
498 * point, we've been running on some set of pagetables constructed by
499 * the boot process.
500 *
501 * If we're booting on native hardware, this will be a pagetable
502 * constructed in arch/x86/kernel/head_32.S. The root of the
503 * pagetable will be swapper_pg_dir.
504 *
505 * If we're booting paravirtualized under a hypervisor, then there are
506 * more options: we may already be running PAE, and the pagetable may
507 * or may not be based in swapper_pg_dir. In any case,
508 * paravirt_pagetable_init() will set up swapper_pg_dir
509 * appropriately for the rest of the initialization to work.
510 *
511 * In general, pagetable_init() assumes that the pagetable may already
512 * be partially populated, and so it avoids stomping on any existing
513 * mappings.
514 */
515 void __init early_ioremap_page_table_range_init(void)
516 {
517 pgd_t *pgd_base = swapper_pg_dir;
518 unsigned long vaddr, end;
519
520 /*
521 * Fixed mappings, only the page table structure has to be
522 * created - mappings will be set by set_fixmap():
523 */
524 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
525 end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
526 page_table_range_init(vaddr, end, pgd_base);
527 early_ioremap_reset();
528 }
529
530 static void __init pagetable_init(void)
531 {
532 pgd_t *pgd_base = swapper_pg_dir;
533
534 permanent_kmaps_init(pgd_base);
535 }
536
537 pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL);
538 EXPORT_SYMBOL_GPL(__supported_pte_mask);
539
540 /* user-defined highmem size */
541 static unsigned int highmem_pages = -1;
542
543 /*
544 * highmem=size forces highmem to be exactly 'size' bytes.
545 * This works even on boxes that have no highmem otherwise.
546 * This also works to reduce highmem size on bigger boxes.
547 */
548 static int __init parse_highmem(char *arg)
549 {
550 if (!arg)
551 return -EINVAL;
552
553 highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT;
554 return 0;
555 }
556 early_param("highmem", parse_highmem);
557
558 #define MSG_HIGHMEM_TOO_BIG \
559 "highmem size (%luMB) is bigger than pages available (%luMB)!\n"
560
561 #define MSG_LOWMEM_TOO_SMALL \
562 "highmem size (%luMB) results in <64MB lowmem, ignoring it!\n"
563 /*
564 * All of RAM fits into lowmem - but if user wants highmem
565 * artificially via the highmem=x boot parameter then create
566 * it:
567 */
568 static void __init lowmem_pfn_init(void)
569 {
570 /* max_low_pfn is 0, we already have early_res support */
571 max_low_pfn = max_pfn;
572
573 if (highmem_pages == -1)
574 highmem_pages = 0;
575 #ifdef CONFIG_HIGHMEM
576 if (highmem_pages >= max_pfn) {
577 printk(KERN_ERR MSG_HIGHMEM_TOO_BIG,
578 pages_to_mb(highmem_pages), pages_to_mb(max_pfn));
579 highmem_pages = 0;
580 }
581 if (highmem_pages) {
582 if (max_low_pfn - highmem_pages < 64*1024*1024/PAGE_SIZE) {
583 printk(KERN_ERR MSG_LOWMEM_TOO_SMALL,
584 pages_to_mb(highmem_pages));
585 highmem_pages = 0;
586 }
587 max_low_pfn -= highmem_pages;
588 }
589 #else
590 if (highmem_pages)
591 printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n");
592 #endif
593 }
594
595 #define MSG_HIGHMEM_TOO_SMALL \
596 "only %luMB highmem pages available, ignoring highmem size of %luMB!\n"
597
598 #define MSG_HIGHMEM_TRIMMED \
599 "Warning: only 4GB will be used. Use a HIGHMEM64G enabled kernel!\n"
600 /*
601 * We have more RAM than fits into lowmem - we try to put it into
602 * highmem, also taking the highmem=x boot parameter into account:
603 */
604 static void __init highmem_pfn_init(void)
605 {
606 max_low_pfn = MAXMEM_PFN;
607
608 if (highmem_pages == -1)
609 highmem_pages = max_pfn - MAXMEM_PFN;
610
611 if (highmem_pages + MAXMEM_PFN < max_pfn)
612 max_pfn = MAXMEM_PFN + highmem_pages;
613
614 if (highmem_pages + MAXMEM_PFN > max_pfn) {
615 printk(KERN_WARNING MSG_HIGHMEM_TOO_SMALL,
616 pages_to_mb(max_pfn - MAXMEM_PFN),
617 pages_to_mb(highmem_pages));
618 highmem_pages = 0;
619 }
620 #ifndef CONFIG_HIGHMEM
621 /* Maximum memory usable is what is directly addressable */
622 printk(KERN_WARNING "Warning only %ldMB will be used.\n", MAXMEM>>20);
623 if (max_pfn > MAX_NONPAE_PFN)
624 printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n");
625 else
626 printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");
627 max_pfn = MAXMEM_PFN;
628 #else /* !CONFIG_HIGHMEM */
629 #ifndef CONFIG_HIGHMEM64G
630 if (max_pfn > MAX_NONPAE_PFN) {
631 max_pfn = MAX_NONPAE_PFN;
632 printk(KERN_WARNING MSG_HIGHMEM_TRIMMED);
633 }
634 #endif /* !CONFIG_HIGHMEM64G */
635 #endif /* !CONFIG_HIGHMEM */
636 }
637
638 /*
639 * Determine low and high memory ranges:
640 */
641 void __init find_low_pfn_range(void)
642 {
643 /* it could update max_pfn */
644
645 if (max_pfn <= MAXMEM_PFN)
646 lowmem_pfn_init();
647 else
648 highmem_pfn_init();
649 }
650
651 #ifndef CONFIG_NEED_MULTIPLE_NODES
652 void __init initmem_init(void)
653 {
654 #ifdef CONFIG_HIGHMEM
655 highstart_pfn = highend_pfn = max_pfn;
656 if (max_pfn > max_low_pfn)
657 highstart_pfn = max_low_pfn;
658 printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
659 pages_to_mb(highend_pfn - highstart_pfn));
660 high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1;
661 #else
662 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1;
663 #endif
664
665 memblock_set_node(0, (phys_addr_t)ULLONG_MAX, &memblock.memory, 0);
666 sparse_memory_present_with_active_regions(0);
667
668 #ifdef CONFIG_FLATMEM
669 max_mapnr = IS_ENABLED(CONFIG_HIGHMEM) ? highend_pfn : max_low_pfn;
670 #endif
671 __vmalloc_start_set = true;
672
673 printk(KERN_NOTICE "%ldMB LOWMEM available.\n",
674 pages_to_mb(max_low_pfn));
675
676 setup_bootmem_allocator();
677 }
678 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
679
680 void __init setup_bootmem_allocator(void)
681 {
682 printk(KERN_INFO " mapped low ram: 0 - %08lx\n",
683 max_pfn_mapped<<PAGE_SHIFT);
684 printk(KERN_INFO " low ram: 0 - %08lx\n", max_low_pfn<<PAGE_SHIFT);
685 }
686
687 /*
688 * paging_init() sets up the page tables - note that the first 8MB are
689 * already mapped by head.S.
690 *
691 * This routines also unmaps the page at virtual kernel address 0, so
692 * that we can trap those pesky NULL-reference errors in the kernel.
693 */
694 void __init paging_init(void)
695 {
696 pagetable_init();
697
698 __flush_tlb_all();
699
700 kmap_init();
701
702 /*
703 * NOTE: at this point the bootmem allocator is fully available.
704 */
705 olpc_dt_build_devicetree();
706 sparse_memory_present_with_active_regions(MAX_NUMNODES);
707 sparse_init();
708 zone_sizes_init();
709 }
710
711 /*
712 * Test if the WP bit works in supervisor mode. It isn't supported on 386's
713 * and also on some strange 486's. All 586+'s are OK. This used to involve
714 * black magic jumps to work around some nasty CPU bugs, but fortunately the
715 * switch to using exceptions got rid of all that.
716 */
717 static void __init test_wp_bit(void)
718 {
719 printk(KERN_INFO
720 "Checking if this processor honours the WP bit even in supervisor mode...");
721
722 /* Any page-aligned address will do, the test is non-destructive */
723 __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_KERNEL_RO);
724 boot_cpu_data.wp_works_ok = do_test_wp_bit();
725 clear_fixmap(FIX_WP_TEST);
726
727 if (!boot_cpu_data.wp_works_ok) {
728 printk(KERN_CONT "No.\n");
729 panic("Linux doesn't support CPUs with broken WP.");
730 } else {
731 printk(KERN_CONT "Ok.\n");
732 }
733 }
734
735 void __init mem_init(void)
736 {
737 pci_iommu_alloc();
738
739 #ifdef CONFIG_FLATMEM
740 BUG_ON(!mem_map);
741 #endif
742 /*
743 * With CONFIG_DEBUG_PAGEALLOC initialization of highmem pages has to
744 * be done before free_all_bootmem(). Memblock use free low memory for
745 * temporary data (see find_range_array()) and for this purpose can use
746 * pages that was already passed to the buddy allocator, hence marked as
747 * not accessible in the page tables when compiled with
748 * CONFIG_DEBUG_PAGEALLOC. Otherwise order of initialization is not
749 * important here.
750 */
751 set_highmem_pages_init();
752
753 /* this will put all low memory onto the freelists */
754 free_all_bootmem();
755
756 after_bootmem = 1;
757
758 mem_init_print_info(NULL);
759 printk(KERN_INFO "virtual kernel memory layout:\n"
760 " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
761 #ifdef CONFIG_HIGHMEM
762 " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
763 #endif
764 " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n"
765 " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n"
766 " .init : 0x%08lx - 0x%08lx (%4ld kB)\n"
767 " .data : 0x%08lx - 0x%08lx (%4ld kB)\n"
768 " .text : 0x%08lx - 0x%08lx (%4ld kB)\n",
769 FIXADDR_START, FIXADDR_TOP,
770 (FIXADDR_TOP - FIXADDR_START) >> 10,
771
772 #ifdef CONFIG_HIGHMEM
773 PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
774 (LAST_PKMAP*PAGE_SIZE) >> 10,
775 #endif
776
777 VMALLOC_START, VMALLOC_END,
778 (VMALLOC_END - VMALLOC_START) >> 20,
779
780 (unsigned long)__va(0), (unsigned long)high_memory,
781 ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
782
783 (unsigned long)&__init_begin, (unsigned long)&__init_end,
784 ((unsigned long)&__init_end -
785 (unsigned long)&__init_begin) >> 10,
786
787 (unsigned long)&_etext, (unsigned long)&_edata,
788 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
789
790 (unsigned long)&_text, (unsigned long)&_etext,
791 ((unsigned long)&_etext - (unsigned long)&_text) >> 10);
792
793 /*
794 * Check boundaries twice: Some fundamental inconsistencies can
795 * be detected at build time already.
796 */
797 #define __FIXADDR_TOP (-PAGE_SIZE)
798 #ifdef CONFIG_HIGHMEM
799 BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START);
800 BUILD_BUG_ON(VMALLOC_END > PKMAP_BASE);
801 #endif
802 #define high_memory (-128UL << 20)
803 BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END);
804 #undef high_memory
805 #undef __FIXADDR_TOP
806
807 #ifdef CONFIG_HIGHMEM
808 BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START);
809 BUG_ON(VMALLOC_END > PKMAP_BASE);
810 #endif
811 BUG_ON(VMALLOC_START >= VMALLOC_END);
812 BUG_ON((unsigned long)high_memory > VMALLOC_START);
813
814 if (boot_cpu_data.wp_works_ok < 0)
815 test_wp_bit();
816 }
817
818 #ifdef CONFIG_MEMORY_HOTPLUG
819 int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
820 {
821 struct pglist_data *pgdata = NODE_DATA(nid);
822 struct zone *zone = pgdata->node_zones +
823 zone_for_memory(nid, start, size, ZONE_HIGHMEM, for_device);
824 unsigned long start_pfn = start >> PAGE_SHIFT;
825 unsigned long nr_pages = size >> PAGE_SHIFT;
826
827 return __add_pages(nid, zone, start_pfn, nr_pages);
828 }
829
830 #ifdef CONFIG_MEMORY_HOTREMOVE
831 int arch_remove_memory(u64 start, u64 size)
832 {
833 unsigned long start_pfn = start >> PAGE_SHIFT;
834 unsigned long nr_pages = size >> PAGE_SHIFT;
835 struct zone *zone;
836
837 zone = page_zone(pfn_to_page(start_pfn));
838 return __remove_pages(zone, start_pfn, nr_pages);
839 }
840 #endif
841 #endif
842
843 /*
844 * This function cannot be __init, since exceptions don't work in that
845 * section. Put this after the callers, so that it cannot be inlined.
846 */
847 static noinline int do_test_wp_bit(void)
848 {
849 char tmp_reg;
850 int flag;
851
852 __asm__ __volatile__(
853 " movb %0, %1 \n"
854 "1: movb %1, %0 \n"
855 " xorl %2, %2 \n"
856 "2: \n"
857 _ASM_EXTABLE(1b,2b)
858 :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)),
859 "=q" (tmp_reg),
860 "=r" (flag)
861 :"2" (1)
862 :"memory");
863
864 return flag;
865 }
866
867 const int rodata_test_data = 0xC3;
868 EXPORT_SYMBOL_GPL(rodata_test_data);
869
870 int kernel_set_to_readonly __read_mostly;
871
872 void set_kernel_text_rw(void)
873 {
874 unsigned long start = PFN_ALIGN(_text);
875 unsigned long size = PFN_ALIGN(_etext) - start;
876
877 if (!kernel_set_to_readonly)
878 return;
879
880 pr_debug("Set kernel text: %lx - %lx for read write\n",
881 start, start+size);
882
883 set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
884 }
885
886 void set_kernel_text_ro(void)
887 {
888 unsigned long start = PFN_ALIGN(_text);
889 unsigned long size = PFN_ALIGN(_etext) - start;
890
891 if (!kernel_set_to_readonly)
892 return;
893
894 pr_debug("Set kernel text: %lx - %lx for read only\n",
895 start, start+size);
896
897 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
898 }
899
900 static void mark_nxdata_nx(void)
901 {
902 /*
903 * When this called, init has already been executed and released,
904 * so everything past _etext should be NX.
905 */
906 unsigned long start = PFN_ALIGN(_etext);
907 /*
908 * This comes from is_kernel_text upper limit. Also HPAGE where used:
909 */
910 unsigned long size = (((unsigned long)__init_end + HPAGE_SIZE) & HPAGE_MASK) - start;
911
912 if (__supported_pte_mask & _PAGE_NX)
913 printk(KERN_INFO "NX-protecting the kernel data: %luk\n", size >> 10);
914 set_pages_nx(virt_to_page(start), size >> PAGE_SHIFT);
915 }
916
917 void mark_rodata_ro(void)
918 {
919 unsigned long start = PFN_ALIGN(_text);
920 unsigned long size = PFN_ALIGN(_etext) - start;
921
922 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
923 printk(KERN_INFO "Write protecting the kernel text: %luk\n",
924 size >> 10);
925
926 kernel_set_to_readonly = 1;
927
928 #ifdef CONFIG_CPA_DEBUG
929 printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n",
930 start, start+size);
931 set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT);
932
933 printk(KERN_INFO "Testing CPA: write protecting again\n");
934 set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT);
935 #endif
936
937 start += size;
938 size = (unsigned long)__end_rodata - start;
939 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
940 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
941 size >> 10);
942 rodata_test();
943
944 #ifdef CONFIG_CPA_DEBUG
945 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size);
946 set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
947
948 printk(KERN_INFO "Testing CPA: write protecting again\n");
949 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
950 #endif
951 mark_nxdata_nx();
952 if (__supported_pte_mask & _PAGE_NX)
953 debug_checkwx();
954 }
955
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.