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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *
4 * Copyright (C) 1995 Linus Torvalds
5 *
6 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
7 */
8
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/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/dma.h>
39#include <asm/fixmap.h>
40#include <asm/e820/api.h>
41#include <asm/apic.h>
42#include <asm/bugs.h>
43#include <asm/tlb.h>
44#include <asm/tlbflush.h>
45#include <asm/olpc_ofw.h>
46#include <asm/pgalloc.h>
47#include <asm/sections.h>
48#include <asm/setup.h>
49#include <asm/set_memory.h>
50#include <asm/page_types.h>
51#include <asm/cpu_entry_area.h>
52#include <asm/init.h>
53#include <asm/pgtable_areas.h>
54#include <asm/numa.h>
55
56#include "mm_internal.h"
57
58unsigned long highstart_pfn, highend_pfn;
59
60bool __read_mostly __vmalloc_start_set = false;
61
62/*
63 * Creates a middle page table and puts a pointer to it in the
64 * given global directory entry. This only returns the gd entry
65 * in non-PAE compilation mode, since the middle layer is folded.
66 */
67static pmd_t * __init one_md_table_init(pgd_t *pgd)
68{
69 p4d_t *p4d;
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 set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
77 p4d = p4d_offset(pgd, 0);
78 pud = pud_offset(p4d, 0);
79 BUG_ON(pmd_table != pmd_offset(pud, 0));
80
81 return pmd_table;
82 }
83#endif
84 p4d = p4d_offset(pgd, 0);
85 pud = pud_offset(p4d, 0);
86 pmd_table = pmd_offset(pud, 0);
87
88 return pmd_table;
89}
90
91/*
92 * Create a page table and place a pointer to it in a middle page
93 * directory entry:
94 */
95static pte_t * __init one_page_table_init(pmd_t *pmd)
96{
97 if (!(pmd_val(*pmd) & _PAGE_PRESENT)) {
98 pte_t *page_table = (pte_t *)alloc_low_page();
99
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
107pmd_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
115pte_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
124static unsigned long __init
125page_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
155static 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 set_pmd(pmd, __pmd(__pa(newpte)|_PAGE_TABLE));
182 BUG_ON(newpte != pte_offset_kernel(pmd, 0));
183 __flush_tlb_all();
184
185 pte = newpte;
186 }
187 BUG_ON(vaddr < fix_to_virt(FIX_KMAP_BEGIN - 1)
188 && vaddr > fix_to_virt(FIX_KMAP_END)
189 && lastpte && lastpte + PTRS_PER_PTE != pte);
190#endif
191 return pte;
192}
193
194/*
195 * This function initializes a certain range of kernel virtual memory
196 * with new bootmem page tables, everywhere page tables are missing in
197 * the given range.
198 *
199 * NOTE: The pagetables are allocated contiguous on the physical space
200 * so we can cache the place of the first one and move around without
201 * checking the pgd every time.
202 */
203static void __init
204page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base)
205{
206 int pgd_idx, pmd_idx;
207 unsigned long vaddr;
208 pgd_t *pgd;
209 pmd_t *pmd;
210 pte_t *pte = NULL;
211 unsigned long count = page_table_range_init_count(start, end);
212 void *adr = NULL;
213
214 if (count)
215 adr = alloc_low_pages(count);
216
217 vaddr = start;
218 pgd_idx = pgd_index(vaddr);
219 pmd_idx = pmd_index(vaddr);
220 pgd = pgd_base + pgd_idx;
221
222 for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
223 pmd = one_md_table_init(pgd);
224 pmd = pmd + pmd_index(vaddr);
225 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);
226 pmd++, pmd_idx++) {
227 pte = page_table_kmap_check(one_page_table_init(pmd),
228 pmd, vaddr, pte, &adr);
229
230 vaddr += PMD_SIZE;
231 }
232 pmd_idx = 0;
233 }
234}
235
236static inline int is_x86_32_kernel_text(unsigned long addr)
237{
238 if (addr >= (unsigned long)_text && addr <= (unsigned long)__init_end)
239 return 1;
240 return 0;
241}
242
243/*
244 * This maps the physical memory to kernel virtual address space, a total
245 * of max_low_pfn pages, by creating page tables starting from address
246 * PAGE_OFFSET:
247 */
248unsigned long __init
249kernel_physical_mapping_init(unsigned long start,
250 unsigned long end,
251 unsigned long page_size_mask,
252 pgprot_t prot)
253{
254 int use_pse = page_size_mask == (1<<PG_LEVEL_2M);
255 unsigned long last_map_addr = end;
256 unsigned long start_pfn, end_pfn;
257 pgd_t *pgd_base = swapper_pg_dir;
258 int pgd_idx, pmd_idx, pte_ofs;
259 unsigned long pfn;
260 pgd_t *pgd;
261 pmd_t *pmd;
262 pte_t *pte;
263 unsigned pages_2m, pages_4k;
264 int mapping_iter;
265
266 start_pfn = start >> PAGE_SHIFT;
267 end_pfn = end >> PAGE_SHIFT;
268
269 /*
270 * First iteration will setup identity mapping using large/small pages
271 * based on use_pse, with other attributes same as set by
272 * the early code in head_32.S
273 *
274 * Second iteration will setup the appropriate attributes (NX, GLOBAL..)
275 * as desired for the kernel identity mapping.
276 *
277 * This two pass mechanism conforms to the TLB app note which says:
278 *
279 * "Software should not write to a paging-structure entry in a way
280 * that would change, for any linear address, both the page size
281 * and either the page frame or attributes."
282 */
283 mapping_iter = 1;
284
285 if (!boot_cpu_has(X86_FEATURE_PSE))
286 use_pse = 0;
287
288repeat:
289 pages_2m = pages_4k = 0;
290 pfn = start_pfn;
291 pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
292 pgd = pgd_base + pgd_idx;
293 for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) {
294 pmd = one_md_table_init(pgd);
295
296 if (pfn >= end_pfn)
297 continue;
298#ifdef CONFIG_X86_PAE
299 pmd_idx = pmd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
300 pmd += pmd_idx;
301#else
302 pmd_idx = 0;
303#endif
304 for (; pmd_idx < PTRS_PER_PMD && pfn < end_pfn;
305 pmd++, pmd_idx++) {
306 unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET;
307
308 /*
309 * Map with big pages if possible, otherwise
310 * create normal page tables:
311 */
312 if (use_pse) {
313 unsigned int addr2;
314 pgprot_t prot = PAGE_KERNEL_LARGE;
315 /*
316 * first pass will use the same initial
317 * identity mapping attribute + _PAGE_PSE.
318 */
319 pgprot_t init_prot =
320 __pgprot(PTE_IDENT_ATTR |
321 _PAGE_PSE);
322
323 pfn &= PMD_MASK >> PAGE_SHIFT;
324 addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE +
325 PAGE_OFFSET + PAGE_SIZE-1;
326
327 if (is_x86_32_kernel_text(addr) ||
328 is_x86_32_kernel_text(addr2))
329 prot = PAGE_KERNEL_LARGE_EXEC;
330
331 pages_2m++;
332 if (mapping_iter == 1)
333 set_pmd(pmd, pfn_pmd(pfn, init_prot));
334 else
335 set_pmd(pmd, pfn_pmd(pfn, prot));
336
337 pfn += PTRS_PER_PTE;
338 continue;
339 }
340 pte = one_page_table_init(pmd);
341
342 pte_ofs = pte_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
343 pte += pte_ofs;
344 for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn;
345 pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) {
346 pgprot_t prot = PAGE_KERNEL;
347 /*
348 * first pass will use the same initial
349 * identity mapping attribute.
350 */
351 pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR);
352
353 if (is_x86_32_kernel_text(addr))
354 prot = PAGE_KERNEL_EXEC;
355
356 pages_4k++;
357 if (mapping_iter == 1) {
358 set_pte(pte, pfn_pte(pfn, init_prot));
359 last_map_addr = (pfn << PAGE_SHIFT) + PAGE_SIZE;
360 } else
361 set_pte(pte, pfn_pte(pfn, prot));
362 }
363 }
364 }
365 if (mapping_iter == 1) {
366 /*
367 * update direct mapping page count only in the first
368 * iteration.
369 */
370 update_page_count(PG_LEVEL_2M, pages_2m);
371 update_page_count(PG_LEVEL_4K, pages_4k);
372
373 /*
374 * local global flush tlb, which will flush the previous
375 * mappings present in both small and large page TLB's.
376 */
377 __flush_tlb_all();
378
379 /*
380 * Second iteration will set the actual desired PTE attributes.
381 */
382 mapping_iter = 2;
383 goto repeat;
384 }
385 return last_map_addr;
386}
387
388#ifdef CONFIG_HIGHMEM
389static void __init permanent_kmaps_init(pgd_t *pgd_base)
390{
391 unsigned long vaddr = PKMAP_BASE;
392
393 page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
394
395 pkmap_page_table = virt_to_kpte(vaddr);
396}
397
398void __init add_highpages_with_active_regions(int nid,
399 unsigned long start_pfn, unsigned long end_pfn)
400{
401 phys_addr_t start, end;
402 u64 i;
403
404 for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &start, &end, NULL) {
405 unsigned long pfn = clamp_t(unsigned long, PFN_UP(start),
406 start_pfn, end_pfn);
407 unsigned long e_pfn = clamp_t(unsigned long, PFN_DOWN(end),
408 start_pfn, end_pfn);
409 for ( ; pfn < e_pfn; pfn++)
410 if (pfn_valid(pfn))
411 free_highmem_page(pfn_to_page(pfn));
412 }
413}
414#else
415static inline void permanent_kmaps_init(pgd_t *pgd_base)
416{
417}
418#endif /* CONFIG_HIGHMEM */
419
420void __init sync_initial_page_table(void)
421{
422 clone_pgd_range(initial_page_table + KERNEL_PGD_BOUNDARY,
423 swapper_pg_dir + KERNEL_PGD_BOUNDARY,
424 KERNEL_PGD_PTRS);
425
426 /*
427 * sync back low identity map too. It is used for example
428 * in the 32-bit EFI stub.
429 */
430 clone_pgd_range(initial_page_table,
431 swapper_pg_dir + KERNEL_PGD_BOUNDARY,
432 min(KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY));
433}
434
435void __init native_pagetable_init(void)
436{
437 unsigned long pfn, va;
438 pgd_t *pgd, *base = swapper_pg_dir;
439 p4d_t *p4d;
440 pud_t *pud;
441 pmd_t *pmd;
442 pte_t *pte;
443
444 /*
445 * Remove any mappings which extend past the end of physical
446 * memory from the boot time page table.
447 * In virtual address space, we should have at least two pages
448 * from VMALLOC_END to pkmap or fixmap according to VMALLOC_END
449 * definition. And max_low_pfn is set to VMALLOC_END physical
450 * address. If initial memory mapping is doing right job, we
451 * should have pte used near max_low_pfn or one pmd is not present.
452 */
453 for (pfn = max_low_pfn; pfn < 1<<(32-PAGE_SHIFT); pfn++) {
454 va = PAGE_OFFSET + (pfn<<PAGE_SHIFT);
455 pgd = base + pgd_index(va);
456 if (!pgd_present(*pgd))
457 break;
458
459 p4d = p4d_offset(pgd, va);
460 pud = pud_offset(p4d, va);
461 pmd = pmd_offset(pud, va);
462 if (!pmd_present(*pmd))
463 break;
464
465 /* should not be large page here */
466 if (pmd_large(*pmd)) {
467 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",
468 pfn, pmd, __pa(pmd));
469 BUG_ON(1);
470 }
471
472 pte = pte_offset_kernel(pmd, va);
473 if (!pte_present(*pte))
474 break;
475
476 printk(KERN_DEBUG "clearing pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx pte: %p pte phys: %lx\n",
477 pfn, pmd, __pa(pmd), pte, __pa(pte));
478 pte_clear(NULL, va, pte);
479 }
480 paging_init();
481}
482
483/*
484 * Build a proper pagetable for the kernel mappings. Up until this
485 * point, we've been running on some set of pagetables constructed by
486 * the boot process.
487 *
488 * This will be a pagetable constructed in arch/x86/kernel/head_32.S.
489 * The root of the pagetable will be swapper_pg_dir.
490 *
491 * In general, pagetable_init() assumes that the pagetable may already
492 * be partially populated, and so it avoids stomping on any existing
493 * mappings.
494 */
495void __init early_ioremap_page_table_range_init(void)
496{
497 pgd_t *pgd_base = swapper_pg_dir;
498 unsigned long vaddr, end;
499
500 /*
501 * Fixed mappings, only the page table structure has to be
502 * created - mappings will be set by set_fixmap():
503 */
504 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
505 end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
506 page_table_range_init(vaddr, end, pgd_base);
507 early_ioremap_reset();
508}
509
510static void __init pagetable_init(void)
511{
512 pgd_t *pgd_base = swapper_pg_dir;
513
514 permanent_kmaps_init(pgd_base);
515}
516
517#define DEFAULT_PTE_MASK ~(_PAGE_NX | _PAGE_GLOBAL)
518/* Bits supported by the hardware: */
519pteval_t __supported_pte_mask __read_mostly = DEFAULT_PTE_MASK;
520/* Bits allowed in normal kernel mappings: */
521pteval_t __default_kernel_pte_mask __read_mostly = DEFAULT_PTE_MASK;
522EXPORT_SYMBOL_GPL(__supported_pte_mask);
523/* Used in PAGE_KERNEL_* macros which are reasonably used out-of-tree: */
524EXPORT_SYMBOL(__default_kernel_pte_mask);
525
526/* user-defined highmem size */
527static unsigned int highmem_pages = -1;
528
529/*
530 * highmem=size forces highmem to be exactly 'size' bytes.
531 * This works even on boxes that have no highmem otherwise.
532 * This also works to reduce highmem size on bigger boxes.
533 */
534static int __init parse_highmem(char *arg)
535{
536 if (!arg)
537 return -EINVAL;
538
539 highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT;
540 return 0;
541}
542early_param("highmem", parse_highmem);
543
544#define MSG_HIGHMEM_TOO_BIG \
545 "highmem size (%luMB) is bigger than pages available (%luMB)!\n"
546
547#define MSG_LOWMEM_TOO_SMALL \
548 "highmem size (%luMB) results in <64MB lowmem, ignoring it!\n"
549/*
550 * All of RAM fits into lowmem - but if user wants highmem
551 * artificially via the highmem=x boot parameter then create
552 * it:
553 */
554static void __init lowmem_pfn_init(void)
555{
556 /* max_low_pfn is 0, we already have early_res support */
557 max_low_pfn = max_pfn;
558
559 if (highmem_pages == -1)
560 highmem_pages = 0;
561#ifdef CONFIG_HIGHMEM
562 if (highmem_pages >= max_pfn) {
563 printk(KERN_ERR MSG_HIGHMEM_TOO_BIG,
564 pages_to_mb(highmem_pages), pages_to_mb(max_pfn));
565 highmem_pages = 0;
566 }
567 if (highmem_pages) {
568 if (max_low_pfn - highmem_pages < 64*1024*1024/PAGE_SIZE) {
569 printk(KERN_ERR MSG_LOWMEM_TOO_SMALL,
570 pages_to_mb(highmem_pages));
571 highmem_pages = 0;
572 }
573 max_low_pfn -= highmem_pages;
574 }
575#else
576 if (highmem_pages)
577 printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n");
578#endif
579}
580
581#define MSG_HIGHMEM_TOO_SMALL \
582 "only %luMB highmem pages available, ignoring highmem size of %luMB!\n"
583
584#define MSG_HIGHMEM_TRIMMED \
585 "Warning: only 4GB will be used. Use a HIGHMEM64G enabled kernel!\n"
586/*
587 * We have more RAM than fits into lowmem - we try to put it into
588 * highmem, also taking the highmem=x boot parameter into account:
589 */
590static void __init highmem_pfn_init(void)
591{
592 max_low_pfn = MAXMEM_PFN;
593
594 if (highmem_pages == -1)
595 highmem_pages = max_pfn - MAXMEM_PFN;
596
597 if (highmem_pages + MAXMEM_PFN < max_pfn)
598 max_pfn = MAXMEM_PFN + highmem_pages;
599
600 if (highmem_pages + MAXMEM_PFN > max_pfn) {
601 printk(KERN_WARNING MSG_HIGHMEM_TOO_SMALL,
602 pages_to_mb(max_pfn - MAXMEM_PFN),
603 pages_to_mb(highmem_pages));
604 highmem_pages = 0;
605 }
606#ifndef CONFIG_HIGHMEM
607 /* Maximum memory usable is what is directly addressable */
608 printk(KERN_WARNING "Warning only %ldMB will be used.\n", MAXMEM>>20);
609 if (max_pfn > MAX_NONPAE_PFN)
610 printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n");
611 else
612 printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");
613 max_pfn = MAXMEM_PFN;
614#else /* !CONFIG_HIGHMEM */
615#ifndef CONFIG_HIGHMEM64G
616 if (max_pfn > MAX_NONPAE_PFN) {
617 max_pfn = MAX_NONPAE_PFN;
618 printk(KERN_WARNING MSG_HIGHMEM_TRIMMED);
619 }
620#endif /* !CONFIG_HIGHMEM64G */
621#endif /* !CONFIG_HIGHMEM */
622}
623
624/*
625 * Determine low and high memory ranges:
626 */
627void __init find_low_pfn_range(void)
628{
629 /* it could update max_pfn */
630
631 if (max_pfn <= MAXMEM_PFN)
632 lowmem_pfn_init();
633 else
634 highmem_pfn_init();
635}
636
637#ifndef CONFIG_NUMA
638void __init initmem_init(void)
639{
640#ifdef CONFIG_HIGHMEM
641 highstart_pfn = highend_pfn = max_pfn;
642 if (max_pfn > max_low_pfn)
643 highstart_pfn = max_low_pfn;
644 printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
645 pages_to_mb(highend_pfn - highstart_pfn));
646 high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1;
647#else
648 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1;
649#endif
650
651 memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
652
653#ifdef CONFIG_FLATMEM
654 max_mapnr = IS_ENABLED(CONFIG_HIGHMEM) ? highend_pfn : max_low_pfn;
655#endif
656 __vmalloc_start_set = true;
657
658 printk(KERN_NOTICE "%ldMB LOWMEM available.\n",
659 pages_to_mb(max_low_pfn));
660
661 setup_bootmem_allocator();
662}
663#endif /* !CONFIG_NUMA */
664
665void __init setup_bootmem_allocator(void)
666{
667 printk(KERN_INFO " mapped low ram: 0 - %08lx\n",
668 max_pfn_mapped<<PAGE_SHIFT);
669 printk(KERN_INFO " low ram: 0 - %08lx\n", max_low_pfn<<PAGE_SHIFT);
670}
671
672/*
673 * paging_init() sets up the page tables - note that the first 8MB are
674 * already mapped by head.S.
675 *
676 * This routines also unmaps the page at virtual kernel address 0, so
677 * that we can trap those pesky NULL-reference errors in the kernel.
678 */
679void __init paging_init(void)
680{
681 pagetable_init();
682
683 __flush_tlb_all();
684
685 /*
686 * NOTE: at this point the bootmem allocator is fully available.
687 */
688 olpc_dt_build_devicetree();
689 sparse_init();
690 zone_sizes_init();
691}
692
693/*
694 * Test if the WP bit works in supervisor mode. It isn't supported on 386's
695 * and also on some strange 486's. All 586+'s are OK. This used to involve
696 * black magic jumps to work around some nasty CPU bugs, but fortunately the
697 * switch to using exceptions got rid of all that.
698 */
699static void __init test_wp_bit(void)
700{
701 char z = 0;
702
703 printk(KERN_INFO "Checking if this processor honours the WP bit even in supervisor mode...");
704
705 __set_fixmap(FIX_WP_TEST, __pa_symbol(empty_zero_page), PAGE_KERNEL_RO);
706
707 if (copy_to_kernel_nofault((char *)fix_to_virt(FIX_WP_TEST), &z, 1)) {
708 clear_fixmap(FIX_WP_TEST);
709 printk(KERN_CONT "Ok.\n");
710 return;
711 }
712
713 printk(KERN_CONT "No.\n");
714 panic("Linux doesn't support CPUs with broken WP.");
715}
716
717void __init mem_init(void)
718{
719 pci_iommu_alloc();
720
721#ifdef CONFIG_FLATMEM
722 BUG_ON(!mem_map);
723#endif
724 /*
725 * With CONFIG_DEBUG_PAGEALLOC initialization of highmem pages has to
726 * be done before memblock_free_all(). Memblock use free low memory for
727 * temporary data (see find_range_array()) and for this purpose can use
728 * pages that was already passed to the buddy allocator, hence marked as
729 * not accessible in the page tables when compiled with
730 * CONFIG_DEBUG_PAGEALLOC. Otherwise order of initialization is not
731 * important here.
732 */
733 set_highmem_pages_init();
734
735 /* this will put all low memory onto the freelists */
736 memblock_free_all();
737
738 after_bootmem = 1;
739 x86_init.hyper.init_after_bootmem();
740
741 /*
742 * Check boundaries twice: Some fundamental inconsistencies can
743 * be detected at build time already.
744 */
745#define __FIXADDR_TOP (-PAGE_SIZE)
746#ifdef CONFIG_HIGHMEM
747 BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START);
748 BUILD_BUG_ON(VMALLOC_END > PKMAP_BASE);
749#endif
750#define high_memory (-128UL << 20)
751 BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END);
752#undef high_memory
753#undef __FIXADDR_TOP
754
755#ifdef CONFIG_HIGHMEM
756 BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START);
757 BUG_ON(VMALLOC_END > PKMAP_BASE);
758#endif
759 BUG_ON(VMALLOC_START >= VMALLOC_END);
760 BUG_ON((unsigned long)high_memory > VMALLOC_START);
761
762 test_wp_bit();
763}
764
765int kernel_set_to_readonly __read_mostly;
766
767static void mark_nxdata_nx(void)
768{
769 /*
770 * When this called, init has already been executed and released,
771 * so everything past _etext should be NX.
772 */
773 unsigned long start = PFN_ALIGN(_etext);
774 /*
775 * This comes from is_x86_32_kernel_text upper limit. Also HPAGE where used:
776 */
777 unsigned long size = (((unsigned long)__init_end + HPAGE_SIZE) & HPAGE_MASK) - start;
778
779 if (__supported_pte_mask & _PAGE_NX)
780 printk(KERN_INFO "NX-protecting the kernel data: %luk\n", size >> 10);
781 set_memory_nx(start, size >> PAGE_SHIFT);
782}
783
784void mark_rodata_ro(void)
785{
786 unsigned long start = PFN_ALIGN(_text);
787 unsigned long size = (unsigned long)__end_rodata - start;
788
789 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
790 pr_info("Write protecting kernel text and read-only data: %luk\n",
791 size >> 10);
792
793 kernel_set_to_readonly = 1;
794
795#ifdef CONFIG_CPA_DEBUG
796 pr_info("Testing CPA: Reverting %lx-%lx\n", start, start + size);
797 set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
798
799 pr_info("Testing CPA: write protecting again\n");
800 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
801#endif
802 mark_nxdata_nx();
803 if (__supported_pte_mask & _PAGE_NX)
804 debug_checkwx();
805}
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/uaccess.h>
39#include <asm/pgtable.h>
40#include <asm/dma.h>
41#include <asm/fixmap.h>
42#include <asm/e820.h>
43#include <asm/apic.h>
44#include <asm/bugs.h>
45#include <asm/tlb.h>
46#include <asm/tlbflush.h>
47#include <asm/olpc_ofw.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#include "mm_internal.h"
57
58unsigned long highstart_pfn, highend_pfn;
59
60static noinline int do_test_wp_bit(void);
61
62bool __read_mostly __vmalloc_start_set = false;
63
64/*
65 * Creates a middle page table and puts a pointer to it in the
66 * given global directory entry. This only returns the gd entry
67 * in non-PAE compilation mode, since the middle layer is folded.
68 */
69static pmd_t * __init one_md_table_init(pgd_t *pgd)
70{
71 pud_t *pud;
72 pmd_t *pmd_table;
73
74#ifdef CONFIG_X86_PAE
75 if (!(pgd_val(*pgd) & _PAGE_PRESENT)) {
76 pmd_table = (pmd_t *)alloc_low_page();
77 paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT);
78 set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
79 pud = pud_offset(pgd, 0);
80 BUG_ON(pmd_table != pmd_offset(pud, 0));
81
82 return pmd_table;
83 }
84#endif
85 pud = pud_offset(pgd, 0);
86 pmd_table = pmd_offset(pud, 0);
87
88 return pmd_table;
89}
90
91/*
92 * Create a page table and place a pointer to it in a middle page
93 * directory entry:
94 */
95static pte_t * __init one_page_table_init(pmd_t *pmd)
96{
97 if (!(pmd_val(*pmd) & _PAGE_PRESENT)) {
98 pte_t *page_table = (pte_t *)alloc_low_page();
99
100 paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT);
101 set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE));
102 BUG_ON(page_table != pte_offset_kernel(pmd, 0));
103 }
104
105 return pte_offset_kernel(pmd, 0);
106}
107
108pmd_t * __init populate_extra_pmd(unsigned long vaddr)
109{
110 int pgd_idx = pgd_index(vaddr);
111 int pmd_idx = pmd_index(vaddr);
112
113 return one_md_table_init(swapper_pg_dir + pgd_idx) + pmd_idx;
114}
115
116pte_t * __init populate_extra_pte(unsigned long vaddr)
117{
118 int pte_idx = pte_index(vaddr);
119 pmd_t *pmd;
120
121 pmd = populate_extra_pmd(vaddr);
122 return one_page_table_init(pmd) + pte_idx;
123}
124
125static unsigned long __init
126page_table_range_init_count(unsigned long start, unsigned long end)
127{
128 unsigned long count = 0;
129#ifdef CONFIG_HIGHMEM
130 int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT;
131 int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT;
132 int pgd_idx, pmd_idx;
133 unsigned long vaddr;
134
135 if (pmd_idx_kmap_begin == pmd_idx_kmap_end)
136 return 0;
137
138 vaddr = start;
139 pgd_idx = pgd_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
155static 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 */
205static void __init
206page_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
238static 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 */
250unsigned long __init
251kernel_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 (!cpu_has_pse)
287 use_pse = 0;
288
289repeat:
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
389pte_t *kmap_pte;
390pgprot_t kmap_prot;
391
392static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr)
393{
394 return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
395 vaddr), vaddr), vaddr);
396}
397
398static void __init kmap_init(void)
399{
400 unsigned long kmap_vstart;
401
402 /*
403 * Cache the first kmap pte:
404 */
405 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
406 kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
407
408 kmap_prot = PAGE_KERNEL;
409}
410
411#ifdef CONFIG_HIGHMEM
412static void __init permanent_kmaps_init(pgd_t *pgd_base)
413{
414 unsigned long vaddr;
415 pgd_t *pgd;
416 pud_t *pud;
417 pmd_t *pmd;
418 pte_t *pte;
419
420 vaddr = PKMAP_BASE;
421 page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
422
423 pgd = swapper_pg_dir + pgd_index(vaddr);
424 pud = pud_offset(pgd, vaddr);
425 pmd = pmd_offset(pud, vaddr);
426 pte = pte_offset_kernel(pmd, vaddr);
427 pkmap_page_table = pte;
428}
429
430void __init add_highpages_with_active_regions(int nid,
431 unsigned long start_pfn, unsigned long end_pfn)
432{
433 phys_addr_t start, end;
434 u64 i;
435
436 for_each_free_mem_range(i, nid, &start, &end, NULL) {
437 unsigned long pfn = clamp_t(unsigned long, PFN_UP(start),
438 start_pfn, end_pfn);
439 unsigned long e_pfn = clamp_t(unsigned long, PFN_DOWN(end),
440 start_pfn, end_pfn);
441 for ( ; pfn < e_pfn; pfn++)
442 if (pfn_valid(pfn))
443 free_highmem_page(pfn_to_page(pfn));
444 }
445}
446#else
447static inline void permanent_kmaps_init(pgd_t *pgd_base)
448{
449}
450#endif /* CONFIG_HIGHMEM */
451
452void __init native_pagetable_init(void)
453{
454 unsigned long pfn, va;
455 pgd_t *pgd, *base = swapper_pg_dir;
456 pud_t *pud;
457 pmd_t *pmd;
458 pte_t *pte;
459
460 /*
461 * Remove any mappings which extend past the end of physical
462 * memory from the boot time page table.
463 * In virtual address space, we should have at least two pages
464 * from VMALLOC_END to pkmap or fixmap according to VMALLOC_END
465 * definition. And max_low_pfn is set to VMALLOC_END physical
466 * address. If initial memory mapping is doing right job, we
467 * should have pte used near max_low_pfn or one pmd is not present.
468 */
469 for (pfn = max_low_pfn; pfn < 1<<(32-PAGE_SHIFT); pfn++) {
470 va = PAGE_OFFSET + (pfn<<PAGE_SHIFT);
471 pgd = base + pgd_index(va);
472 if (!pgd_present(*pgd))
473 break;
474
475 pud = pud_offset(pgd, va);
476 pmd = pmd_offset(pud, va);
477 if (!pmd_present(*pmd))
478 break;
479
480 /* should not be large page here */
481 if (pmd_large(*pmd)) {
482 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",
483 pfn, pmd, __pa(pmd));
484 BUG_ON(1);
485 }
486
487 pte = pte_offset_kernel(pmd, va);
488 if (!pte_present(*pte))
489 break;
490
491 printk(KERN_DEBUG "clearing pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx pte: %p pte phys: %lx\n",
492 pfn, pmd, __pa(pmd), pte, __pa(pte));
493 pte_clear(NULL, va, pte);
494 }
495 paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT);
496 paging_init();
497}
498
499/*
500 * Build a proper pagetable for the kernel mappings. Up until this
501 * point, we've been running on some set of pagetables constructed by
502 * the boot process.
503 *
504 * If we're booting on native hardware, this will be a pagetable
505 * constructed in arch/x86/kernel/head_32.S. The root of the
506 * pagetable will be swapper_pg_dir.
507 *
508 * If we're booting paravirtualized under a hypervisor, then there are
509 * more options: we may already be running PAE, and the pagetable may
510 * or may not be based in swapper_pg_dir. In any case,
511 * paravirt_pagetable_init() will set up swapper_pg_dir
512 * appropriately for the rest of the initialization to work.
513 *
514 * In general, pagetable_init() assumes that the pagetable may already
515 * be partially populated, and so it avoids stomping on any existing
516 * mappings.
517 */
518void __init early_ioremap_page_table_range_init(void)
519{
520 pgd_t *pgd_base = swapper_pg_dir;
521 unsigned long vaddr, end;
522
523 /*
524 * Fixed mappings, only the page table structure has to be
525 * created - mappings will be set by set_fixmap():
526 */
527 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
528 end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
529 page_table_range_init(vaddr, end, pgd_base);
530 early_ioremap_reset();
531}
532
533static void __init pagetable_init(void)
534{
535 pgd_t *pgd_base = swapper_pg_dir;
536
537 permanent_kmaps_init(pgd_base);
538}
539
540pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL | _PAGE_IOMAP);
541EXPORT_SYMBOL_GPL(__supported_pte_mask);
542
543/* user-defined highmem size */
544static unsigned int highmem_pages = -1;
545
546/*
547 * highmem=size forces highmem to be exactly 'size' bytes.
548 * This works even on boxes that have no highmem otherwise.
549 * This also works to reduce highmem size on bigger boxes.
550 */
551static int __init parse_highmem(char *arg)
552{
553 if (!arg)
554 return -EINVAL;
555
556 highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT;
557 return 0;
558}
559early_param("highmem", parse_highmem);
560
561#define MSG_HIGHMEM_TOO_BIG \
562 "highmem size (%luMB) is bigger than pages available (%luMB)!\n"
563
564#define MSG_LOWMEM_TOO_SMALL \
565 "highmem size (%luMB) results in <64MB lowmem, ignoring it!\n"
566/*
567 * All of RAM fits into lowmem - but if user wants highmem
568 * artificially via the highmem=x boot parameter then create
569 * it:
570 */
571static void __init lowmem_pfn_init(void)
572{
573 /* max_low_pfn is 0, we already have early_res support */
574 max_low_pfn = max_pfn;
575
576 if (highmem_pages == -1)
577 highmem_pages = 0;
578#ifdef CONFIG_HIGHMEM
579 if (highmem_pages >= max_pfn) {
580 printk(KERN_ERR MSG_HIGHMEM_TOO_BIG,
581 pages_to_mb(highmem_pages), pages_to_mb(max_pfn));
582 highmem_pages = 0;
583 }
584 if (highmem_pages) {
585 if (max_low_pfn - highmem_pages < 64*1024*1024/PAGE_SIZE) {
586 printk(KERN_ERR MSG_LOWMEM_TOO_SMALL,
587 pages_to_mb(highmem_pages));
588 highmem_pages = 0;
589 }
590 max_low_pfn -= highmem_pages;
591 }
592#else
593 if (highmem_pages)
594 printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n");
595#endif
596}
597
598#define MSG_HIGHMEM_TOO_SMALL \
599 "only %luMB highmem pages available, ignoring highmem size of %luMB!\n"
600
601#define MSG_HIGHMEM_TRIMMED \
602 "Warning: only 4GB will be used. Use a HIGHMEM64G enabled kernel!\n"
603/*
604 * We have more RAM than fits into lowmem - we try to put it into
605 * highmem, also taking the highmem=x boot parameter into account:
606 */
607static void __init highmem_pfn_init(void)
608{
609 max_low_pfn = MAXMEM_PFN;
610
611 if (highmem_pages == -1)
612 highmem_pages = max_pfn - MAXMEM_PFN;
613
614 if (highmem_pages + MAXMEM_PFN < max_pfn)
615 max_pfn = MAXMEM_PFN + highmem_pages;
616
617 if (highmem_pages + MAXMEM_PFN > max_pfn) {
618 printk(KERN_WARNING MSG_HIGHMEM_TOO_SMALL,
619 pages_to_mb(max_pfn - MAXMEM_PFN),
620 pages_to_mb(highmem_pages));
621 highmem_pages = 0;
622 }
623#ifndef CONFIG_HIGHMEM
624 /* Maximum memory usable is what is directly addressable */
625 printk(KERN_WARNING "Warning only %ldMB will be used.\n", MAXMEM>>20);
626 if (max_pfn > MAX_NONPAE_PFN)
627 printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n");
628 else
629 printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");
630 max_pfn = MAXMEM_PFN;
631#else /* !CONFIG_HIGHMEM */
632#ifndef CONFIG_HIGHMEM64G
633 if (max_pfn > MAX_NONPAE_PFN) {
634 max_pfn = MAX_NONPAE_PFN;
635 printk(KERN_WARNING MSG_HIGHMEM_TRIMMED);
636 }
637#endif /* !CONFIG_HIGHMEM64G */
638#endif /* !CONFIG_HIGHMEM */
639}
640
641/*
642 * Determine low and high memory ranges:
643 */
644void __init find_low_pfn_range(void)
645{
646 /* it could update max_pfn */
647
648 if (max_pfn <= MAXMEM_PFN)
649 lowmem_pfn_init();
650 else
651 highmem_pfn_init();
652}
653
654#ifndef CONFIG_NEED_MULTIPLE_NODES
655void __init initmem_init(void)
656{
657#ifdef CONFIG_HIGHMEM
658 highstart_pfn = highend_pfn = max_pfn;
659 if (max_pfn > max_low_pfn)
660 highstart_pfn = max_low_pfn;
661 printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
662 pages_to_mb(highend_pfn - highstart_pfn));
663 high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1;
664#else
665 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1;
666#endif
667
668 memblock_set_node(0, (phys_addr_t)ULLONG_MAX, &memblock.memory, 0);
669 sparse_memory_present_with_active_regions(0);
670
671#ifdef CONFIG_FLATMEM
672 max_mapnr = IS_ENABLED(CONFIG_HIGHMEM) ? highend_pfn : max_low_pfn;
673#endif
674 __vmalloc_start_set = true;
675
676 printk(KERN_NOTICE "%ldMB LOWMEM available.\n",
677 pages_to_mb(max_low_pfn));
678
679 setup_bootmem_allocator();
680}
681#endif /* !CONFIG_NEED_MULTIPLE_NODES */
682
683void __init setup_bootmem_allocator(void)
684{
685 printk(KERN_INFO " mapped low ram: 0 - %08lx\n",
686 max_pfn_mapped<<PAGE_SHIFT);
687 printk(KERN_INFO " low ram: 0 - %08lx\n", max_low_pfn<<PAGE_SHIFT);
688}
689
690/*
691 * paging_init() sets up the page tables - note that the first 8MB are
692 * already mapped by head.S.
693 *
694 * This routines also unmaps the page at virtual kernel address 0, so
695 * that we can trap those pesky NULL-reference errors in the kernel.
696 */
697void __init paging_init(void)
698{
699 pagetable_init();
700
701 __flush_tlb_all();
702
703 kmap_init();
704
705 /*
706 * NOTE: at this point the bootmem allocator is fully available.
707 */
708 olpc_dt_build_devicetree();
709 sparse_memory_present_with_active_regions(MAX_NUMNODES);
710 sparse_init();
711 zone_sizes_init();
712}
713
714/*
715 * Test if the WP bit works in supervisor mode. It isn't supported on 386's
716 * and also on some strange 486's. All 586+'s are OK. This used to involve
717 * black magic jumps to work around some nasty CPU bugs, but fortunately the
718 * switch to using exceptions got rid of all that.
719 */
720static void __init test_wp_bit(void)
721{
722 printk(KERN_INFO
723 "Checking if this processor honours the WP bit even in supervisor mode...");
724
725 /* Any page-aligned address will do, the test is non-destructive */
726 __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_KERNEL_RO);
727 boot_cpu_data.wp_works_ok = do_test_wp_bit();
728 clear_fixmap(FIX_WP_TEST);
729
730 if (!boot_cpu_data.wp_works_ok) {
731 printk(KERN_CONT "No.\n");
732 panic("Linux doesn't support CPUs with broken WP.");
733 } else {
734 printk(KERN_CONT "Ok.\n");
735 }
736}
737
738void __init mem_init(void)
739{
740 pci_iommu_alloc();
741
742#ifdef CONFIG_FLATMEM
743 BUG_ON(!mem_map);
744#endif
745 /*
746 * With CONFIG_DEBUG_PAGEALLOC initialization of highmem pages has to
747 * be done before free_all_bootmem(). Memblock use free low memory for
748 * temporary data (see find_range_array()) and for this purpose can use
749 * pages that was already passed to the buddy allocator, hence marked as
750 * not accessible in the page tables when compiled with
751 * CONFIG_DEBUG_PAGEALLOC. Otherwise order of initialization is not
752 * important here.
753 */
754 set_highmem_pages_init();
755
756 /* this will put all low memory onto the freelists */
757 free_all_bootmem();
758
759 after_bootmem = 1;
760
761 mem_init_print_info(NULL);
762 printk(KERN_INFO "virtual kernel memory layout:\n"
763 " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
764#ifdef CONFIG_HIGHMEM
765 " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
766#endif
767 " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n"
768 " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n"
769 " .init : 0x%08lx - 0x%08lx (%4ld kB)\n"
770 " .data : 0x%08lx - 0x%08lx (%4ld kB)\n"
771 " .text : 0x%08lx - 0x%08lx (%4ld kB)\n",
772 FIXADDR_START, FIXADDR_TOP,
773 (FIXADDR_TOP - FIXADDR_START) >> 10,
774
775#ifdef CONFIG_HIGHMEM
776 PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
777 (LAST_PKMAP*PAGE_SIZE) >> 10,
778#endif
779
780 VMALLOC_START, VMALLOC_END,
781 (VMALLOC_END - VMALLOC_START) >> 20,
782
783 (unsigned long)__va(0), (unsigned long)high_memory,
784 ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
785
786 (unsigned long)&__init_begin, (unsigned long)&__init_end,
787 ((unsigned long)&__init_end -
788 (unsigned long)&__init_begin) >> 10,
789
790 (unsigned long)&_etext, (unsigned long)&_edata,
791 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
792
793 (unsigned long)&_text, (unsigned long)&_etext,
794 ((unsigned long)&_etext - (unsigned long)&_text) >> 10);
795
796 /*
797 * Check boundaries twice: Some fundamental inconsistencies can
798 * be detected at build time already.
799 */
800#define __FIXADDR_TOP (-PAGE_SIZE)
801#ifdef CONFIG_HIGHMEM
802 BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START);
803 BUILD_BUG_ON(VMALLOC_END > PKMAP_BASE);
804#endif
805#define high_memory (-128UL << 20)
806 BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END);
807#undef high_memory
808#undef __FIXADDR_TOP
809#ifdef CONFIG_RANDOMIZE_BASE
810 BUILD_BUG_ON(CONFIG_RANDOMIZE_BASE_MAX_OFFSET > KERNEL_IMAGE_SIZE);
811#endif
812
813#ifdef CONFIG_HIGHMEM
814 BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START);
815 BUG_ON(VMALLOC_END > PKMAP_BASE);
816#endif
817 BUG_ON(VMALLOC_START >= VMALLOC_END);
818 BUG_ON((unsigned long)high_memory > VMALLOC_START);
819
820 if (boot_cpu_data.wp_works_ok < 0)
821 test_wp_bit();
822}
823
824#ifdef CONFIG_MEMORY_HOTPLUG
825int arch_add_memory(int nid, u64 start, u64 size)
826{
827 struct pglist_data *pgdata = NODE_DATA(nid);
828 struct zone *zone = pgdata->node_zones + ZONE_HIGHMEM;
829 unsigned long start_pfn = start >> PAGE_SHIFT;
830 unsigned long nr_pages = size >> PAGE_SHIFT;
831
832 return __add_pages(nid, zone, start_pfn, nr_pages);
833}
834
835#ifdef CONFIG_MEMORY_HOTREMOVE
836int arch_remove_memory(u64 start, u64 size)
837{
838 unsigned long start_pfn = start >> PAGE_SHIFT;
839 unsigned long nr_pages = size >> PAGE_SHIFT;
840 struct zone *zone;
841
842 zone = page_zone(pfn_to_page(start_pfn));
843 return __remove_pages(zone, start_pfn, nr_pages);
844}
845#endif
846#endif
847
848/*
849 * This function cannot be __init, since exceptions don't work in that
850 * section. Put this after the callers, so that it cannot be inlined.
851 */
852static noinline int do_test_wp_bit(void)
853{
854 char tmp_reg;
855 int flag;
856
857 __asm__ __volatile__(
858 " movb %0, %1 \n"
859 "1: movb %1, %0 \n"
860 " xorl %2, %2 \n"
861 "2: \n"
862 _ASM_EXTABLE(1b,2b)
863 :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)),
864 "=q" (tmp_reg),
865 "=r" (flag)
866 :"2" (1)
867 :"memory");
868
869 return flag;
870}
871
872#ifdef CONFIG_DEBUG_RODATA
873const int rodata_test_data = 0xC3;
874EXPORT_SYMBOL_GPL(rodata_test_data);
875
876int kernel_set_to_readonly __read_mostly;
877
878void set_kernel_text_rw(void)
879{
880 unsigned long start = PFN_ALIGN(_text);
881 unsigned long size = PFN_ALIGN(_etext) - start;
882
883 if (!kernel_set_to_readonly)
884 return;
885
886 pr_debug("Set kernel text: %lx - %lx for read write\n",
887 start, start+size);
888
889 set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
890}
891
892void set_kernel_text_ro(void)
893{
894 unsigned long start = PFN_ALIGN(_text);
895 unsigned long size = PFN_ALIGN(_etext) - start;
896
897 if (!kernel_set_to_readonly)
898 return;
899
900 pr_debug("Set kernel text: %lx - %lx for read only\n",
901 start, start+size);
902
903 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
904}
905
906static void mark_nxdata_nx(void)
907{
908 /*
909 * When this called, init has already been executed and released,
910 * so everything past _etext should be NX.
911 */
912 unsigned long start = PFN_ALIGN(_etext);
913 /*
914 * This comes from is_kernel_text upper limit. Also HPAGE where used:
915 */
916 unsigned long size = (((unsigned long)__init_end + HPAGE_SIZE) & HPAGE_MASK) - start;
917
918 if (__supported_pte_mask & _PAGE_NX)
919 printk(KERN_INFO "NX-protecting the kernel data: %luk\n", size >> 10);
920 set_pages_nx(virt_to_page(start), size >> PAGE_SHIFT);
921}
922
923void mark_rodata_ro(void)
924{
925 unsigned long start = PFN_ALIGN(_text);
926 unsigned long size = PFN_ALIGN(_etext) - start;
927
928 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
929 printk(KERN_INFO "Write protecting the kernel text: %luk\n",
930 size >> 10);
931
932 kernel_set_to_readonly = 1;
933
934#ifdef CONFIG_CPA_DEBUG
935 printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n",
936 start, start+size);
937 set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT);
938
939 printk(KERN_INFO "Testing CPA: write protecting again\n");
940 set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT);
941#endif
942
943 start += size;
944 size = (unsigned long)__end_rodata - start;
945 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
946 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
947 size >> 10);
948 rodata_test();
949
950#ifdef CONFIG_CPA_DEBUG
951 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size);
952 set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
953
954 printk(KERN_INFO "Testing CPA: write protecting again\n");
955 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
956#endif
957 mark_nxdata_nx();
958}
959#endif
960