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