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1da177e4 LT |
1 | /* |
2 | * linux/arch/i386/mm/init.c | |
3 | * | |
4 | * Copyright (C) 1995 Linus Torvalds | |
5 | * | |
6 | * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 | |
7 | */ | |
8 | ||
1da177e4 LT |
9 | #include <linux/module.h> |
10 | #include <linux/signal.h> | |
11 | #include <linux/sched.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/errno.h> | |
14 | #include <linux/string.h> | |
15 | #include <linux/types.h> | |
16 | #include <linux/ptrace.h> | |
17 | #include <linux/mman.h> | |
18 | #include <linux/mm.h> | |
19 | #include <linux/hugetlb.h> | |
20 | #include <linux/swap.h> | |
21 | #include <linux/smp.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/highmem.h> | |
24 | #include <linux/pagemap.h> | |
6fb14755 | 25 | #include <linux/pfn.h> |
c9cf5528 | 26 | #include <linux/poison.h> |
1da177e4 LT |
27 | #include <linux/bootmem.h> |
28 | #include <linux/slab.h> | |
29 | #include <linux/proc_fs.h> | |
30 | #include <linux/efi.h> | |
05039b92 | 31 | #include <linux/memory_hotplug.h> |
27d99f7e | 32 | #include <linux/initrd.h> |
55b2355e | 33 | #include <linux/cpumask.h> |
1da177e4 LT |
34 | |
35 | #include <asm/processor.h> | |
36 | #include <asm/system.h> | |
37 | #include <asm/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/tlb.h> | |
44 | #include <asm/tlbflush.h> | |
45 | #include <asm/sections.h> | |
b239fb25 | 46 | #include <asm/paravirt.h> |
1da177e4 LT |
47 | |
48 | unsigned int __VMALLOC_RESERVE = 128 << 20; | |
49 | ||
50 | DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); | |
51 | unsigned long highstart_pfn, highend_pfn; | |
52 | ||
53 | static int noinline do_test_wp_bit(void); | |
54 | ||
55 | /* | |
56 | * Creates a middle page table and puts a pointer to it in the | |
57 | * given global directory entry. This only returns the gd entry | |
58 | * in non-PAE compilation mode, since the middle layer is folded. | |
59 | */ | |
60 | static pmd_t * __init one_md_table_init(pgd_t *pgd) | |
61 | { | |
62 | pud_t *pud; | |
63 | pmd_t *pmd_table; | |
64 | ||
65 | #ifdef CONFIG_X86_PAE | |
b239fb25 JF |
66 | if (!(pgd_val(*pgd) & _PAGE_PRESENT)) { |
67 | pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE); | |
68 | ||
69 | paravirt_alloc_pd(__pa(pmd_table) >> PAGE_SHIFT); | |
70 | set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT)); | |
71 | pud = pud_offset(pgd, 0); | |
72 | if (pmd_table != pmd_offset(pud, 0)) | |
73 | BUG(); | |
74 | } | |
75 | #endif | |
1da177e4 LT |
76 | pud = pud_offset(pgd, 0); |
77 | pmd_table = pmd_offset(pud, 0); | |
1da177e4 LT |
78 | return pmd_table; |
79 | } | |
80 | ||
81 | /* | |
82 | * Create a page table and place a pointer to it in a middle page | |
83 | * directory entry. | |
84 | */ | |
85 | static pte_t * __init one_page_table_init(pmd_t *pmd) | |
86 | { | |
b239fb25 | 87 | if (!(pmd_val(*pmd) & _PAGE_PRESENT)) { |
1da177e4 | 88 | pte_t *page_table = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE); |
b239fb25 | 89 | |
fdb4c338 | 90 | paravirt_alloc_pt(&init_mm, __pa(page_table) >> PAGE_SHIFT); |
1da177e4 | 91 | set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE)); |
b239fb25 | 92 | BUG_ON(page_table != pte_offset_kernel(pmd, 0)); |
1da177e4 LT |
93 | } |
94 | ||
95 | return pte_offset_kernel(pmd, 0); | |
96 | } | |
97 | ||
98 | /* | |
99 | * This function initializes a certain range of kernel virtual memory | |
100 | * with new bootmem page tables, everywhere page tables are missing in | |
101 | * the given range. | |
102 | */ | |
103 | ||
104 | /* | |
105 | * NOTE: The pagetables are allocated contiguous on the physical space | |
106 | * so we can cache the place of the first one and move around without | |
107 | * checking the pgd every time. | |
108 | */ | |
109 | static void __init page_table_range_init (unsigned long start, unsigned long end, pgd_t *pgd_base) | |
110 | { | |
111 | pgd_t *pgd; | |
1da177e4 LT |
112 | pmd_t *pmd; |
113 | int pgd_idx, pmd_idx; | |
114 | unsigned long vaddr; | |
115 | ||
116 | vaddr = start; | |
117 | pgd_idx = pgd_index(vaddr); | |
118 | pmd_idx = pmd_index(vaddr); | |
119 | pgd = pgd_base + pgd_idx; | |
120 | ||
121 | for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) { | |
b239fb25 JF |
122 | pmd = one_md_table_init(pgd); |
123 | pmd = pmd + pmd_index(vaddr); | |
1da177e4 | 124 | for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end); pmd++, pmd_idx++) { |
b239fb25 | 125 | one_page_table_init(pmd); |
1da177e4 LT |
126 | |
127 | vaddr += PMD_SIZE; | |
128 | } | |
129 | pmd_idx = 0; | |
130 | } | |
131 | } | |
132 | ||
133 | static inline int is_kernel_text(unsigned long addr) | |
134 | { | |
135 | if (addr >= PAGE_OFFSET && addr <= (unsigned long)__init_end) | |
136 | return 1; | |
137 | return 0; | |
138 | } | |
139 | ||
140 | /* | |
141 | * This maps the physical memory to kernel virtual address space, a total | |
142 | * of max_low_pfn pages, by creating page tables starting from address | |
143 | * PAGE_OFFSET. | |
144 | */ | |
145 | static void __init kernel_physical_mapping_init(pgd_t *pgd_base) | |
146 | { | |
147 | unsigned long pfn; | |
148 | pgd_t *pgd; | |
149 | pmd_t *pmd; | |
150 | pte_t *pte; | |
151 | int pgd_idx, pmd_idx, pte_ofs; | |
152 | ||
153 | pgd_idx = pgd_index(PAGE_OFFSET); | |
154 | pgd = pgd_base + pgd_idx; | |
155 | pfn = 0; | |
156 | ||
157 | for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) { | |
158 | pmd = one_md_table_init(pgd); | |
159 | if (pfn >= max_low_pfn) | |
160 | continue; | |
161 | for (pmd_idx = 0; pmd_idx < PTRS_PER_PMD && pfn < max_low_pfn; pmd++, pmd_idx++) { | |
162 | unsigned int address = pfn * PAGE_SIZE + PAGE_OFFSET; | |
163 | ||
164 | /* Map with big pages if possible, otherwise create normal page tables. */ | |
165 | if (cpu_has_pse) { | |
166 | unsigned int address2 = (pfn + PTRS_PER_PTE - 1) * PAGE_SIZE + PAGE_OFFSET + PAGE_SIZE-1; | |
1da177e4 LT |
167 | if (is_kernel_text(address) || is_kernel_text(address2)) |
168 | set_pmd(pmd, pfn_pmd(pfn, PAGE_KERNEL_LARGE_EXEC)); | |
169 | else | |
170 | set_pmd(pmd, pfn_pmd(pfn, PAGE_KERNEL_LARGE)); | |
b239fb25 | 171 | |
1da177e4 LT |
172 | pfn += PTRS_PER_PTE; |
173 | } else { | |
174 | pte = one_page_table_init(pmd); | |
175 | ||
b239fb25 JF |
176 | for (pte_ofs = 0; |
177 | pte_ofs < PTRS_PER_PTE && pfn < max_low_pfn; | |
178 | pte++, pfn++, pte_ofs++, address += PAGE_SIZE) { | |
179 | if (is_kernel_text(address)) | |
180 | set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC)); | |
181 | else | |
182 | set_pte(pte, pfn_pte(pfn, PAGE_KERNEL)); | |
1da177e4 LT |
183 | } |
184 | } | |
185 | } | |
186 | } | |
187 | } | |
188 | ||
189 | static inline int page_kills_ppro(unsigned long pagenr) | |
190 | { | |
191 | if (pagenr >= 0x70000 && pagenr <= 0x7003F) | |
192 | return 1; | |
193 | return 0; | |
194 | } | |
195 | ||
5b505b90 | 196 | int page_is_ram(unsigned long pagenr) |
1da177e4 LT |
197 | { |
198 | int i; | |
199 | unsigned long addr, end; | |
200 | ||
201 | if (efi_enabled) { | |
202 | efi_memory_desc_t *md; | |
7ae65fd3 | 203 | void *p; |
1da177e4 | 204 | |
7ae65fd3 MT |
205 | for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { |
206 | md = p; | |
1da177e4 LT |
207 | if (!is_available_memory(md)) |
208 | continue; | |
209 | addr = (md->phys_addr+PAGE_SIZE-1) >> PAGE_SHIFT; | |
210 | end = (md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT)) >> PAGE_SHIFT; | |
211 | ||
212 | if ((pagenr >= addr) && (pagenr < end)) | |
213 | return 1; | |
214 | } | |
215 | return 0; | |
216 | } | |
217 | ||
218 | for (i = 0; i < e820.nr_map; i++) { | |
219 | ||
220 | if (e820.map[i].type != E820_RAM) /* not usable memory */ | |
221 | continue; | |
222 | /* | |
223 | * !!!FIXME!!! Some BIOSen report areas as RAM that | |
224 | * are not. Notably the 640->1Mb area. We need a sanity | |
225 | * check here. | |
226 | */ | |
227 | addr = (e820.map[i].addr+PAGE_SIZE-1) >> PAGE_SHIFT; | |
228 | end = (e820.map[i].addr+e820.map[i].size) >> PAGE_SHIFT; | |
229 | if ((pagenr >= addr) && (pagenr < end)) | |
230 | return 1; | |
231 | } | |
232 | return 0; | |
233 | } | |
234 | ||
235 | #ifdef CONFIG_HIGHMEM | |
236 | pte_t *kmap_pte; | |
237 | pgprot_t kmap_prot; | |
238 | ||
239 | #define kmap_get_fixmap_pte(vaddr) \ | |
240 | pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), vaddr), (vaddr)), (vaddr)) | |
241 | ||
242 | static void __init kmap_init(void) | |
243 | { | |
244 | unsigned long kmap_vstart; | |
245 | ||
246 | /* cache the first kmap pte */ | |
247 | kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN); | |
248 | kmap_pte = kmap_get_fixmap_pte(kmap_vstart); | |
249 | ||
250 | kmap_prot = PAGE_KERNEL; | |
251 | } | |
252 | ||
253 | static void __init permanent_kmaps_init(pgd_t *pgd_base) | |
254 | { | |
255 | pgd_t *pgd; | |
256 | pud_t *pud; | |
257 | pmd_t *pmd; | |
258 | pte_t *pte; | |
259 | unsigned long vaddr; | |
260 | ||
261 | vaddr = PKMAP_BASE; | |
262 | page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base); | |
263 | ||
264 | pgd = swapper_pg_dir + pgd_index(vaddr); | |
265 | pud = pud_offset(pgd, vaddr); | |
266 | pmd = pmd_offset(pud, vaddr); | |
267 | pte = pte_offset_kernel(pmd, vaddr); | |
268 | pkmap_page_table = pte; | |
269 | } | |
270 | ||
c09b4240 | 271 | static void __meminit free_new_highpage(struct page *page) |
05039b92 | 272 | { |
7835e98b | 273 | init_page_count(page); |
05039b92 DH |
274 | __free_page(page); |
275 | totalhigh_pages++; | |
276 | } | |
277 | ||
278 | void __init add_one_highpage_init(struct page *page, int pfn, int bad_ppro) | |
1da177e4 LT |
279 | { |
280 | if (page_is_ram(pfn) && !(bad_ppro && page_kills_ppro(pfn))) { | |
281 | ClearPageReserved(page); | |
05039b92 | 282 | free_new_highpage(page); |
1da177e4 LT |
283 | } else |
284 | SetPageReserved(page); | |
285 | } | |
286 | ||
0e0be25d | 287 | static int __meminit add_one_highpage_hotplug(struct page *page, unsigned long pfn) |
05039b92 DH |
288 | { |
289 | free_new_highpage(page); | |
290 | totalram_pages++; | |
291 | #ifdef CONFIG_FLATMEM | |
292 | max_mapnr = max(pfn, max_mapnr); | |
293 | #endif | |
294 | num_physpages++; | |
295 | return 0; | |
296 | } | |
297 | ||
298 | /* | |
299 | * Not currently handling the NUMA case. | |
300 | * Assuming single node and all memory that | |
301 | * has been added dynamically that would be | |
302 | * onlined here is in HIGHMEM | |
303 | */ | |
0e0be25d | 304 | void __meminit online_page(struct page *page) |
05039b92 DH |
305 | { |
306 | ClearPageReserved(page); | |
307 | add_one_highpage_hotplug(page, page_to_pfn(page)); | |
308 | } | |
309 | ||
310 | ||
05b79bdc AW |
311 | #ifdef CONFIG_NUMA |
312 | extern void set_highmem_pages_init(int); | |
313 | #else | |
1da177e4 LT |
314 | static void __init set_highmem_pages_init(int bad_ppro) |
315 | { | |
316 | int pfn; | |
317 | for (pfn = highstart_pfn; pfn < highend_pfn; pfn++) | |
05039b92 | 318 | add_one_highpage_init(pfn_to_page(pfn), pfn, bad_ppro); |
1da177e4 LT |
319 | totalram_pages += totalhigh_pages; |
320 | } | |
05b79bdc | 321 | #endif /* CONFIG_FLATMEM */ |
1da177e4 LT |
322 | |
323 | #else | |
324 | #define kmap_init() do { } while (0) | |
325 | #define permanent_kmaps_init(pgd_base) do { } while (0) | |
326 | #define set_highmem_pages_init(bad_ppro) do { } while (0) | |
327 | #endif /* CONFIG_HIGHMEM */ | |
328 | ||
329 | unsigned long long __PAGE_KERNEL = _PAGE_KERNEL; | |
129f6946 | 330 | EXPORT_SYMBOL(__PAGE_KERNEL); |
1da177e4 LT |
331 | unsigned long long __PAGE_KERNEL_EXEC = _PAGE_KERNEL_EXEC; |
332 | ||
05b79bdc | 333 | #ifdef CONFIG_NUMA |
1da177e4 | 334 | extern void __init remap_numa_kva(void); |
05b79bdc AW |
335 | #else |
336 | #define remap_numa_kva() do {} while (0) | |
1da177e4 LT |
337 | #endif |
338 | ||
b239fb25 | 339 | void __init native_pagetable_setup_start(pgd_t *base) |
1da177e4 | 340 | { |
1da177e4 LT |
341 | #ifdef CONFIG_X86_PAE |
342 | int i; | |
b239fb25 JF |
343 | |
344 | /* | |
345 | * Init entries of the first-level page table to the | |
346 | * zero page, if they haven't already been set up. | |
347 | * | |
348 | * In a normal native boot, we'll be running on a | |
349 | * pagetable rooted in swapper_pg_dir, but not in PAE | |
350 | * mode, so this will end up clobbering the mappings | |
351 | * for the lower 24Mbytes of the address space, | |
352 | * without affecting the kernel address space. | |
353 | */ | |
354 | for (i = 0; i < USER_PTRS_PER_PGD; i++) | |
355 | set_pgd(&base[i], | |
356 | __pgd(__pa(empty_zero_page) | _PAGE_PRESENT)); | |
357 | ||
358 | /* Make sure kernel address space is empty so that a pagetable | |
359 | will be allocated for it. */ | |
360 | memset(&base[USER_PTRS_PER_PGD], 0, | |
361 | KERNEL_PGD_PTRS * sizeof(pgd_t)); | |
c119ecce ZA |
362 | #else |
363 | paravirt_alloc_pd(__pa(swapper_pg_dir) >> PAGE_SHIFT); | |
1da177e4 | 364 | #endif |
b239fb25 JF |
365 | } |
366 | ||
367 | void __init native_pagetable_setup_done(pgd_t *base) | |
368 | { | |
369 | #ifdef CONFIG_X86_PAE | |
370 | /* | |
371 | * Add low memory identity-mappings - SMP needs it when | |
372 | * starting up on an AP from real-mode. In the non-PAE | |
373 | * case we already have these mappings through head.S. | |
374 | * All user-space mappings are explicitly cleared after | |
375 | * SMP startup. | |
376 | */ | |
377 | set_pgd(&base[0], base[USER_PTRS_PER_PGD]); | |
378 | #endif | |
379 | } | |
380 | ||
381 | /* | |
382 | * Build a proper pagetable for the kernel mappings. Up until this | |
383 | * point, we've been running on some set of pagetables constructed by | |
384 | * the boot process. | |
385 | * | |
386 | * If we're booting on native hardware, this will be a pagetable | |
387 | * constructed in arch/i386/kernel/head.S, and not running in PAE mode | |
388 | * (even if we'll end up running in PAE). The root of the pagetable | |
389 | * will be swapper_pg_dir. | |
390 | * | |
391 | * If we're booting paravirtualized under a hypervisor, then there are | |
392 | * more options: we may already be running PAE, and the pagetable may | |
393 | * or may not be based in swapper_pg_dir. In any case, | |
394 | * paravirt_pagetable_setup_start() will set up swapper_pg_dir | |
395 | * appropriately for the rest of the initialization to work. | |
396 | * | |
397 | * In general, pagetable_init() assumes that the pagetable may already | |
398 | * be partially populated, and so it avoids stomping on any existing | |
399 | * mappings. | |
400 | */ | |
401 | static void __init pagetable_init (void) | |
402 | { | |
403 | unsigned long vaddr, end; | |
404 | pgd_t *pgd_base = swapper_pg_dir; | |
405 | ||
406 | paravirt_pagetable_setup_start(pgd_base); | |
1da177e4 LT |
407 | |
408 | /* Enable PSE if available */ | |
b239fb25 | 409 | if (cpu_has_pse) |
1da177e4 | 410 | set_in_cr4(X86_CR4_PSE); |
1da177e4 LT |
411 | |
412 | /* Enable PGE if available */ | |
413 | if (cpu_has_pge) { | |
414 | set_in_cr4(X86_CR4_PGE); | |
415 | __PAGE_KERNEL |= _PAGE_GLOBAL; | |
416 | __PAGE_KERNEL_EXEC |= _PAGE_GLOBAL; | |
417 | } | |
418 | ||
419 | kernel_physical_mapping_init(pgd_base); | |
420 | remap_numa_kva(); | |
421 | ||
422 | /* | |
423 | * Fixed mappings, only the page table structure has to be | |
424 | * created - mappings will be set by set_fixmap(): | |
425 | */ | |
426 | vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; | |
b239fb25 JF |
427 | end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK; |
428 | page_table_range_init(vaddr, end, pgd_base); | |
1da177e4 LT |
429 | |
430 | permanent_kmaps_init(pgd_base); | |
431 | ||
b239fb25 | 432 | paravirt_pagetable_setup_done(pgd_base); |
1da177e4 LT |
433 | } |
434 | ||
b0cb1a19 | 435 | #if defined(CONFIG_HIBERNATION) || defined(CONFIG_ACPI) |
1da177e4 LT |
436 | /* |
437 | * Swap suspend & friends need this for resume because things like the intel-agp | |
438 | * driver might have split up a kernel 4MB mapping. | |
439 | */ | |
440 | char __nosavedata swsusp_pg_dir[PAGE_SIZE] | |
441 | __attribute__ ((aligned (PAGE_SIZE))); | |
442 | ||
443 | static inline void save_pg_dir(void) | |
444 | { | |
445 | memcpy(swsusp_pg_dir, swapper_pg_dir, PAGE_SIZE); | |
446 | } | |
447 | #else | |
448 | static inline void save_pg_dir(void) | |
449 | { | |
450 | } | |
451 | #endif | |
452 | ||
453 | void zap_low_mappings (void) | |
454 | { | |
455 | int i; | |
456 | ||
457 | save_pg_dir(); | |
458 | ||
459 | /* | |
460 | * Zap initial low-memory mappings. | |
461 | * | |
462 | * Note that "pgd_clear()" doesn't do it for | |
463 | * us, because pgd_clear() is a no-op on i386. | |
464 | */ | |
465 | for (i = 0; i < USER_PTRS_PER_PGD; i++) | |
466 | #ifdef CONFIG_X86_PAE | |
467 | set_pgd(swapper_pg_dir+i, __pgd(1 + __pa(empty_zero_page))); | |
468 | #else | |
469 | set_pgd(swapper_pg_dir+i, __pgd(0)); | |
470 | #endif | |
471 | flush_tlb_all(); | |
472 | } | |
473 | ||
d5321abe JB |
474 | int nx_enabled = 0; |
475 | ||
476 | #ifdef CONFIG_X86_PAE | |
477 | ||
1da177e4 | 478 | static int disable_nx __initdata = 0; |
6c231b7b | 479 | u64 __supported_pte_mask __read_mostly = ~_PAGE_NX; |
bdef40a6 | 480 | EXPORT_SYMBOL_GPL(__supported_pte_mask); |
1da177e4 LT |
481 | |
482 | /* | |
483 | * noexec = on|off | |
484 | * | |
485 | * Control non executable mappings. | |
486 | * | |
487 | * on Enable | |
488 | * off Disable | |
489 | */ | |
1a3f239d | 490 | static int __init noexec_setup(char *str) |
1da177e4 | 491 | { |
1a3f239d RR |
492 | if (!str || !strcmp(str, "on")) { |
493 | if (cpu_has_nx) { | |
494 | __supported_pte_mask |= _PAGE_NX; | |
495 | disable_nx = 0; | |
496 | } | |
497 | } else if (!strcmp(str,"off")) { | |
1da177e4 LT |
498 | disable_nx = 1; |
499 | __supported_pte_mask &= ~_PAGE_NX; | |
1a3f239d RR |
500 | } else |
501 | return -EINVAL; | |
502 | ||
503 | return 0; | |
1da177e4 | 504 | } |
1a3f239d | 505 | early_param("noexec", noexec_setup); |
1da177e4 | 506 | |
1da177e4 LT |
507 | static void __init set_nx(void) |
508 | { | |
509 | unsigned int v[4], l, h; | |
510 | ||
511 | if (cpu_has_pae && (cpuid_eax(0x80000000) > 0x80000001)) { | |
512 | cpuid(0x80000001, &v[0], &v[1], &v[2], &v[3]); | |
513 | if ((v[3] & (1 << 20)) && !disable_nx) { | |
514 | rdmsr(MSR_EFER, l, h); | |
515 | l |= EFER_NX; | |
516 | wrmsr(MSR_EFER, l, h); | |
517 | nx_enabled = 1; | |
518 | __supported_pte_mask |= _PAGE_NX; | |
519 | } | |
520 | } | |
521 | } | |
522 | ||
523 | /* | |
524 | * Enables/disables executability of a given kernel page and | |
525 | * returns the previous setting. | |
526 | */ | |
527 | int __init set_kernel_exec(unsigned long vaddr, int enable) | |
528 | { | |
529 | pte_t *pte; | |
530 | int ret = 1; | |
531 | ||
532 | if (!nx_enabled) | |
533 | goto out; | |
534 | ||
535 | pte = lookup_address(vaddr); | |
536 | BUG_ON(!pte); | |
537 | ||
538 | if (!pte_exec_kernel(*pte)) | |
539 | ret = 0; | |
540 | ||
541 | if (enable) | |
542 | pte->pte_high &= ~(1 << (_PAGE_BIT_NX - 32)); | |
543 | else | |
544 | pte->pte_high |= 1 << (_PAGE_BIT_NX - 32); | |
789e6ac0 | 545 | pte_update_defer(&init_mm, vaddr, pte); |
1da177e4 LT |
546 | __flush_tlb_all(); |
547 | out: | |
548 | return ret; | |
549 | } | |
550 | ||
551 | #endif | |
552 | ||
553 | /* | |
554 | * paging_init() sets up the page tables - note that the first 8MB are | |
555 | * already mapped by head.S. | |
556 | * | |
557 | * This routines also unmaps the page at virtual kernel address 0, so | |
558 | * that we can trap those pesky NULL-reference errors in the kernel. | |
559 | */ | |
560 | void __init paging_init(void) | |
561 | { | |
562 | #ifdef CONFIG_X86_PAE | |
563 | set_nx(); | |
564 | if (nx_enabled) | |
565 | printk("NX (Execute Disable) protection: active\n"); | |
566 | #endif | |
567 | ||
568 | pagetable_init(); | |
569 | ||
570 | load_cr3(swapper_pg_dir); | |
571 | ||
572 | #ifdef CONFIG_X86_PAE | |
573 | /* | |
574 | * We will bail out later - printk doesn't work right now so | |
575 | * the user would just see a hanging kernel. | |
576 | */ | |
577 | if (cpu_has_pae) | |
578 | set_in_cr4(X86_CR4_PAE); | |
579 | #endif | |
580 | __flush_tlb_all(); | |
581 | ||
582 | kmap_init(); | |
583 | } | |
584 | ||
585 | /* | |
586 | * Test if the WP bit works in supervisor mode. It isn't supported on 386's | |
587 | * and also on some strange 486's (NexGen etc.). All 586+'s are OK. This | |
588 | * used to involve black magic jumps to work around some nasty CPU bugs, | |
589 | * but fortunately the switch to using exceptions got rid of all that. | |
590 | */ | |
591 | ||
592 | static void __init test_wp_bit(void) | |
593 | { | |
594 | printk("Checking if this processor honours the WP bit even in supervisor mode... "); | |
595 | ||
596 | /* Any page-aligned address will do, the test is non-destructive */ | |
597 | __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_READONLY); | |
598 | boot_cpu_data.wp_works_ok = do_test_wp_bit(); | |
599 | clear_fixmap(FIX_WP_TEST); | |
600 | ||
601 | if (!boot_cpu_data.wp_works_ok) { | |
602 | printk("No.\n"); | |
603 | #ifdef CONFIG_X86_WP_WORKS_OK | |
604 | panic("This kernel doesn't support CPU's with broken WP. Recompile it for a 386!"); | |
605 | #endif | |
606 | } else { | |
607 | printk("Ok.\n"); | |
608 | } | |
609 | } | |
610 | ||
1da177e4 LT |
611 | static struct kcore_list kcore_mem, kcore_vmalloc; |
612 | ||
613 | void __init mem_init(void) | |
614 | { | |
615 | extern int ppro_with_ram_bug(void); | |
616 | int codesize, reservedpages, datasize, initsize; | |
617 | int tmp; | |
618 | int bad_ppro; | |
619 | ||
05b79bdc | 620 | #ifdef CONFIG_FLATMEM |
8d8f3cbe | 621 | BUG_ON(!mem_map); |
1da177e4 LT |
622 | #endif |
623 | ||
624 | bad_ppro = ppro_with_ram_bug(); | |
625 | ||
626 | #ifdef CONFIG_HIGHMEM | |
627 | /* check that fixmap and pkmap do not overlap */ | |
628 | if (PKMAP_BASE+LAST_PKMAP*PAGE_SIZE >= FIXADDR_START) { | |
629 | printk(KERN_ERR "fixmap and kmap areas overlap - this will crash\n"); | |
630 | printk(KERN_ERR "pkstart: %lxh pkend: %lxh fixstart %lxh\n", | |
631 | PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE, FIXADDR_START); | |
632 | BUG(); | |
633 | } | |
634 | #endif | |
635 | ||
1da177e4 LT |
636 | /* this will put all low memory onto the freelists */ |
637 | totalram_pages += free_all_bootmem(); | |
638 | ||
639 | reservedpages = 0; | |
640 | for (tmp = 0; tmp < max_low_pfn; tmp++) | |
641 | /* | |
642 | * Only count reserved RAM pages | |
643 | */ | |
644 | if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp))) | |
645 | reservedpages++; | |
646 | ||
647 | set_highmem_pages_init(bad_ppro); | |
648 | ||
649 | codesize = (unsigned long) &_etext - (unsigned long) &_text; | |
650 | datasize = (unsigned long) &_edata - (unsigned long) &_etext; | |
651 | initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; | |
652 | ||
653 | kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT); | |
654 | kclist_add(&kcore_vmalloc, (void *)VMALLOC_START, | |
655 | VMALLOC_END-VMALLOC_START); | |
656 | ||
657 | printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init, %ldk highmem)\n", | |
658 | (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), | |
659 | num_physpages << (PAGE_SHIFT-10), | |
660 | codesize >> 10, | |
661 | reservedpages << (PAGE_SHIFT-10), | |
662 | datasize >> 10, | |
663 | initsize >> 10, | |
664 | (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)) | |
665 | ); | |
666 | ||
052e7994 JF |
667 | #if 1 /* double-sanity-check paranoia */ |
668 | printk("virtual kernel memory layout:\n" | |
669 | " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n" | |
670 | #ifdef CONFIG_HIGHMEM | |
671 | " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n" | |
672 | #endif | |
673 | " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n" | |
674 | " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n" | |
675 | " .init : 0x%08lx - 0x%08lx (%4ld kB)\n" | |
676 | " .data : 0x%08lx - 0x%08lx (%4ld kB)\n" | |
677 | " .text : 0x%08lx - 0x%08lx (%4ld kB)\n", | |
678 | FIXADDR_START, FIXADDR_TOP, | |
679 | (FIXADDR_TOP - FIXADDR_START) >> 10, | |
680 | ||
681 | #ifdef CONFIG_HIGHMEM | |
682 | PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE, | |
683 | (LAST_PKMAP*PAGE_SIZE) >> 10, | |
684 | #endif | |
685 | ||
686 | VMALLOC_START, VMALLOC_END, | |
687 | (VMALLOC_END - VMALLOC_START) >> 20, | |
688 | ||
689 | (unsigned long)__va(0), (unsigned long)high_memory, | |
690 | ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20, | |
691 | ||
692 | (unsigned long)&__init_begin, (unsigned long)&__init_end, | |
693 | ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10, | |
694 | ||
695 | (unsigned long)&_etext, (unsigned long)&_edata, | |
696 | ((unsigned long)&_edata - (unsigned long)&_etext) >> 10, | |
697 | ||
698 | (unsigned long)&_text, (unsigned long)&_etext, | |
699 | ((unsigned long)&_etext - (unsigned long)&_text) >> 10); | |
700 | ||
701 | #ifdef CONFIG_HIGHMEM | |
702 | BUG_ON(PKMAP_BASE+LAST_PKMAP*PAGE_SIZE > FIXADDR_START); | |
703 | BUG_ON(VMALLOC_END > PKMAP_BASE); | |
704 | #endif | |
705 | BUG_ON(VMALLOC_START > VMALLOC_END); | |
706 | BUG_ON((unsigned long)high_memory > VMALLOC_START); | |
707 | #endif /* double-sanity-check paranoia */ | |
708 | ||
1da177e4 LT |
709 | #ifdef CONFIG_X86_PAE |
710 | if (!cpu_has_pae) | |
711 | panic("cannot execute a PAE-enabled kernel on a PAE-less CPU!"); | |
712 | #endif | |
713 | if (boot_cpu_data.wp_works_ok < 0) | |
714 | test_wp_bit(); | |
715 | ||
716 | /* | |
717 | * Subtle. SMP is doing it's boot stuff late (because it has to | |
718 | * fork idle threads) - but it also needs low mappings for the | |
719 | * protected-mode entry to work. We zap these entries only after | |
720 | * the WP-bit has been tested. | |
721 | */ | |
722 | #ifndef CONFIG_SMP | |
723 | zap_low_mappings(); | |
724 | #endif | |
725 | } | |
726 | ||
ad8f5797 | 727 | #ifdef CONFIG_MEMORY_HOTPLUG |
bc02af93 | 728 | int arch_add_memory(int nid, u64 start, u64 size) |
05039b92 | 729 | { |
7c7e9425 | 730 | struct pglist_data *pgdata = NODE_DATA(nid); |
776ed98b | 731 | struct zone *zone = pgdata->node_zones + ZONE_HIGHMEM; |
05039b92 DH |
732 | unsigned long start_pfn = start >> PAGE_SHIFT; |
733 | unsigned long nr_pages = size >> PAGE_SHIFT; | |
734 | ||
735 | return __add_pages(zone, start_pfn, nr_pages); | |
736 | } | |
737 | ||
738 | int remove_memory(u64 start, u64 size) | |
739 | { | |
740 | return -EINVAL; | |
741 | } | |
7c7e9425 | 742 | EXPORT_SYMBOL_GPL(remove_memory); |
9d99aaa3 | 743 | #endif |
05039b92 | 744 | |
e18b890b | 745 | struct kmem_cache *pmd_cache; |
1da177e4 LT |
746 | |
747 | void __init pgtable_cache_init(void) | |
748 | { | |
4f817847 | 749 | if (PTRS_PER_PMD > 1) |
1da177e4 | 750 | pmd_cache = kmem_cache_create("pmd", |
4f817847 JF |
751 | PTRS_PER_PMD*sizeof(pmd_t), |
752 | PTRS_PER_PMD*sizeof(pmd_t), | |
753 | SLAB_PANIC, | |
754 | pmd_ctor); | |
1da177e4 LT |
755 | } |
756 | ||
757 | /* | |
758 | * This function cannot be __init, since exceptions don't work in that | |
759 | * section. Put this after the callers, so that it cannot be inlined. | |
760 | */ | |
761 | static int noinline do_test_wp_bit(void) | |
762 | { | |
763 | char tmp_reg; | |
764 | int flag; | |
765 | ||
766 | __asm__ __volatile__( | |
767 | " movb %0,%1 \n" | |
768 | "1: movb %1,%0 \n" | |
769 | " xorl %2,%2 \n" | |
770 | "2: \n" | |
771 | ".section __ex_table,\"a\"\n" | |
772 | " .align 4 \n" | |
773 | " .long 1b,2b \n" | |
774 | ".previous \n" | |
775 | :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)), | |
776 | "=q" (tmp_reg), | |
777 | "=r" (flag) | |
778 | :"2" (1) | |
779 | :"memory"); | |
780 | ||
781 | return flag; | |
782 | } | |
783 | ||
63aaf308 AV |
784 | #ifdef CONFIG_DEBUG_RODATA |
785 | ||
63aaf308 AV |
786 | void mark_rodata_ro(void) |
787 | { | |
6fb14755 JB |
788 | unsigned long start = PFN_ALIGN(_text); |
789 | unsigned long size = PFN_ALIGN(_etext) - start; | |
63aaf308 | 790 | |
602033ed LT |
791 | #ifndef CONFIG_KPROBES |
792 | #ifdef CONFIG_HOTPLUG_CPU | |
793 | /* It must still be possible to apply SMP alternatives. */ | |
794 | if (num_possible_cpus() <= 1) | |
795 | #endif | |
796 | { | |
797 | change_page_attr(virt_to_page(start), | |
798 | size >> PAGE_SHIFT, PAGE_KERNEL_RX); | |
799 | printk("Write protecting the kernel text: %luk\n", size >> 10); | |
800 | } | |
801 | #endif | |
6fb14755 JB |
802 | start += size; |
803 | size = (unsigned long)__end_rodata - start; | |
804 | change_page_attr(virt_to_page(start), | |
805 | size >> PAGE_SHIFT, PAGE_KERNEL_RO); | |
806 | printk("Write protecting the kernel read-only data: %luk\n", | |
807 | size >> 10); | |
63aaf308 AV |
808 | |
809 | /* | |
810 | * change_page_attr() requires a global_flush_tlb() call after it. | |
811 | * We do this after the printk so that if something went wrong in the | |
812 | * change, the printk gets out at least to give a better debug hint | |
813 | * of who is the culprit. | |
814 | */ | |
815 | global_flush_tlb(); | |
816 | } | |
817 | #endif | |
818 | ||
9a0b5817 GH |
819 | void free_init_pages(char *what, unsigned long begin, unsigned long end) |
820 | { | |
821 | unsigned long addr; | |
822 | ||
823 | for (addr = begin; addr < end; addr += PAGE_SIZE) { | |
e3ebadd9 LT |
824 | ClearPageReserved(virt_to_page(addr)); |
825 | init_page_count(virt_to_page(addr)); | |
826 | memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE); | |
827 | free_page(addr); | |
9a0b5817 GH |
828 | totalram_pages++; |
829 | } | |
6fb14755 | 830 | printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10); |
9a0b5817 GH |
831 | } |
832 | ||
833 | void free_initmem(void) | |
834 | { | |
835 | free_init_pages("unused kernel memory", | |
e3ebadd9 LT |
836 | (unsigned long)(&__init_begin), |
837 | (unsigned long)(&__init_end)); | |
9a0b5817 | 838 | } |
63aaf308 | 839 | |
1da177e4 LT |
840 | #ifdef CONFIG_BLK_DEV_INITRD |
841 | void free_initrd_mem(unsigned long start, unsigned long end) | |
842 | { | |
e3ebadd9 | 843 | free_init_pages("initrd memory", start, end); |
1da177e4 LT |
844 | } |
845 | #endif | |
9a0b5817 | 846 |