Commit | Line | Data |
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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> | |
05039b92 | 30 | #include <linux/memory_hotplug.h> |
27d99f7e | 31 | #include <linux/initrd.h> |
55b2355e | 32 | #include <linux/cpumask.h> |
1da177e4 | 33 | |
f832ff18 | 34 | #include <asm/asm.h> |
1da177e4 LT |
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> | |
8550eb99 | 43 | #include <asm/bugs.h> |
1da177e4 LT |
44 | #include <asm/tlb.h> |
45 | #include <asm/tlbflush.h> | |
a5a19c63 | 46 | #include <asm/pgalloc.h> |
1da177e4 | 47 | #include <asm/sections.h> |
b239fb25 | 48 | #include <asm/paravirt.h> |
551889a6 | 49 | #include <asm/setup.h> |
1da177e4 LT |
50 | |
51 | unsigned int __VMALLOC_RESERVE = 128 << 20; | |
52 | ||
53 | DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); | |
54 | unsigned long highstart_pfn, highend_pfn; | |
55 | ||
8550eb99 | 56 | static noinline int do_test_wp_bit(void); |
1da177e4 LT |
57 | |
58 | /* | |
59 | * Creates a middle page table and puts a pointer to it in the | |
60 | * given global directory entry. This only returns the gd entry | |
61 | * in non-PAE compilation mode, since the middle layer is folded. | |
62 | */ | |
63 | static pmd_t * __init one_md_table_init(pgd_t *pgd) | |
64 | { | |
65 | pud_t *pud; | |
66 | pmd_t *pmd_table; | |
8550eb99 | 67 | |
1da177e4 | 68 | #ifdef CONFIG_X86_PAE |
b239fb25 JF |
69 | if (!(pgd_val(*pgd) & _PAGE_PRESENT)) { |
70 | pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE); | |
71 | ||
6c435456 | 72 | paravirt_alloc_pd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT); |
b239fb25 JF |
73 | set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT)); |
74 | pud = pud_offset(pgd, 0); | |
8550eb99 | 75 | BUG_ON(pmd_table != pmd_offset(pud, 0)); |
b239fb25 JF |
76 | } |
77 | #endif | |
1da177e4 LT |
78 | pud = pud_offset(pgd, 0); |
79 | pmd_table = pmd_offset(pud, 0); | |
8550eb99 | 80 | |
1da177e4 LT |
81 | return pmd_table; |
82 | } | |
83 | ||
84 | /* | |
85 | * Create a page table and place a pointer to it in a middle page | |
8550eb99 | 86 | * directory entry: |
1da177e4 LT |
87 | */ |
88 | static pte_t * __init one_page_table_init(pmd_t *pmd) | |
89 | { | |
b239fb25 | 90 | if (!(pmd_val(*pmd) & _PAGE_PRESENT)) { |
509a80c4 IM |
91 | pte_t *page_table = NULL; |
92 | ||
93 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
94 | page_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE); | |
95 | #endif | |
8550eb99 | 96 | if (!page_table) { |
509a80c4 IM |
97 | page_table = |
98 | (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE); | |
8550eb99 | 99 | } |
b239fb25 | 100 | |
fdb4c338 | 101 | paravirt_alloc_pt(&init_mm, __pa(page_table) >> PAGE_SHIFT); |
1da177e4 | 102 | set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE)); |
b239fb25 | 103 | BUG_ON(page_table != pte_offset_kernel(pmd, 0)); |
1da177e4 | 104 | } |
509a80c4 | 105 | |
1da177e4 LT |
106 | return pte_offset_kernel(pmd, 0); |
107 | } | |
108 | ||
109 | /* | |
8550eb99 | 110 | * This function initializes a certain range of kernel virtual memory |
1da177e4 LT |
111 | * with new bootmem page tables, everywhere page tables are missing in |
112 | * the given range. | |
8550eb99 IM |
113 | * |
114 | * NOTE: The pagetables are allocated contiguous on the physical space | |
115 | * so we can cache the place of the first one and move around without | |
1da177e4 LT |
116 | * checking the pgd every time. |
117 | */ | |
8550eb99 IM |
118 | static void __init |
119 | page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base) | |
1da177e4 | 120 | { |
1da177e4 LT |
121 | int pgd_idx, pmd_idx; |
122 | unsigned long vaddr; | |
8550eb99 IM |
123 | pgd_t *pgd; |
124 | pmd_t *pmd; | |
1da177e4 LT |
125 | |
126 | vaddr = start; | |
127 | pgd_idx = pgd_index(vaddr); | |
128 | pmd_idx = pmd_index(vaddr); | |
129 | pgd = pgd_base + pgd_idx; | |
130 | ||
131 | for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) { | |
b239fb25 JF |
132 | pmd = one_md_table_init(pgd); |
133 | pmd = pmd + pmd_index(vaddr); | |
8550eb99 IM |
134 | for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end); |
135 | pmd++, pmd_idx++) { | |
b239fb25 | 136 | one_page_table_init(pmd); |
1da177e4 LT |
137 | |
138 | vaddr += PMD_SIZE; | |
139 | } | |
140 | pmd_idx = 0; | |
141 | } | |
142 | } | |
143 | ||
144 | static inline int is_kernel_text(unsigned long addr) | |
145 | { | |
146 | if (addr >= PAGE_OFFSET && addr <= (unsigned long)__init_end) | |
147 | return 1; | |
148 | return 0; | |
149 | } | |
150 | ||
151 | /* | |
8550eb99 IM |
152 | * This maps the physical memory to kernel virtual address space, a total |
153 | * of max_low_pfn pages, by creating page tables starting from address | |
154 | * PAGE_OFFSET: | |
1da177e4 LT |
155 | */ |
156 | static void __init kernel_physical_mapping_init(pgd_t *pgd_base) | |
157 | { | |
8550eb99 | 158 | int pgd_idx, pmd_idx, pte_ofs; |
1da177e4 LT |
159 | unsigned long pfn; |
160 | pgd_t *pgd; | |
161 | pmd_t *pmd; | |
162 | pte_t *pte; | |
1da177e4 LT |
163 | |
164 | pgd_idx = pgd_index(PAGE_OFFSET); | |
165 | pgd = pgd_base + pgd_idx; | |
166 | pfn = 0; | |
167 | ||
168 | for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) { | |
169 | pmd = one_md_table_init(pgd); | |
170 | if (pfn >= max_low_pfn) | |
171 | continue; | |
8550eb99 | 172 | |
f3f20de8 JF |
173 | for (pmd_idx = 0; |
174 | pmd_idx < PTRS_PER_PMD && pfn < max_low_pfn; | |
175 | pmd++, pmd_idx++) { | |
8550eb99 | 176 | unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET; |
1da177e4 | 177 | |
8550eb99 IM |
178 | /* |
179 | * Map with big pages if possible, otherwise | |
180 | * create normal page tables: | |
181 | */ | |
1da177e4 | 182 | if (cpu_has_pse) { |
8550eb99 | 183 | unsigned int addr2; |
f3f20de8 JF |
184 | pgprot_t prot = PAGE_KERNEL_LARGE; |
185 | ||
8550eb99 | 186 | addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE + |
f3f20de8 JF |
187 | PAGE_OFFSET + PAGE_SIZE-1; |
188 | ||
8550eb99 IM |
189 | if (is_kernel_text(addr) || |
190 | is_kernel_text(addr2)) | |
f3f20de8 JF |
191 | prot = PAGE_KERNEL_LARGE_EXEC; |
192 | ||
193 | set_pmd(pmd, pfn_pmd(pfn, prot)); | |
b239fb25 | 194 | |
1da177e4 | 195 | pfn += PTRS_PER_PTE; |
8550eb99 IM |
196 | continue; |
197 | } | |
198 | pte = one_page_table_init(pmd); | |
1da177e4 | 199 | |
8550eb99 IM |
200 | for (pte_ofs = 0; |
201 | pte_ofs < PTRS_PER_PTE && pfn < max_low_pfn; | |
202 | pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) { | |
203 | pgprot_t prot = PAGE_KERNEL; | |
f3f20de8 | 204 | |
8550eb99 IM |
205 | if (is_kernel_text(addr)) |
206 | prot = PAGE_KERNEL_EXEC; | |
f3f20de8 | 207 | |
8550eb99 | 208 | set_pte(pte, pfn_pte(pfn, prot)); |
1da177e4 LT |
209 | } |
210 | } | |
211 | } | |
212 | } | |
213 | ||
214 | static inline int page_kills_ppro(unsigned long pagenr) | |
215 | { | |
216 | if (pagenr >= 0x70000 && pagenr <= 0x7003F) | |
217 | return 1; | |
218 | return 0; | |
219 | } | |
220 | ||
1da177e4 LT |
221 | #ifdef CONFIG_HIGHMEM |
222 | pte_t *kmap_pte; | |
223 | pgprot_t kmap_prot; | |
224 | ||
8550eb99 IM |
225 | static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr) |
226 | { | |
227 | return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), | |
228 | vaddr), vaddr), vaddr); | |
229 | } | |
1da177e4 LT |
230 | |
231 | static void __init kmap_init(void) | |
232 | { | |
233 | unsigned long kmap_vstart; | |
234 | ||
8550eb99 IM |
235 | /* |
236 | * Cache the first kmap pte: | |
237 | */ | |
1da177e4 LT |
238 | kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN); |
239 | kmap_pte = kmap_get_fixmap_pte(kmap_vstart); | |
240 | ||
241 | kmap_prot = PAGE_KERNEL; | |
242 | } | |
243 | ||
244 | static void __init permanent_kmaps_init(pgd_t *pgd_base) | |
245 | { | |
8550eb99 | 246 | unsigned long vaddr; |
1da177e4 LT |
247 | pgd_t *pgd; |
248 | pud_t *pud; | |
249 | pmd_t *pmd; | |
250 | pte_t *pte; | |
1da177e4 LT |
251 | |
252 | vaddr = PKMAP_BASE; | |
253 | page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base); | |
254 | ||
255 | pgd = swapper_pg_dir + pgd_index(vaddr); | |
256 | pud = pud_offset(pgd, vaddr); | |
257 | pmd = pmd_offset(pud, vaddr); | |
258 | pte = pte_offset_kernel(pmd, vaddr); | |
8550eb99 | 259 | pkmap_page_table = pte; |
1da177e4 LT |
260 | } |
261 | ||
c09b4240 | 262 | static void __meminit free_new_highpage(struct page *page) |
05039b92 | 263 | { |
7835e98b | 264 | init_page_count(page); |
05039b92 DH |
265 | __free_page(page); |
266 | totalhigh_pages++; | |
267 | } | |
268 | ||
269 | void __init add_one_highpage_init(struct page *page, int pfn, int bad_ppro) | |
1da177e4 LT |
270 | { |
271 | if (page_is_ram(pfn) && !(bad_ppro && page_kills_ppro(pfn))) { | |
272 | ClearPageReserved(page); | |
05039b92 | 273 | free_new_highpage(page); |
1da177e4 LT |
274 | } else |
275 | SetPageReserved(page); | |
276 | } | |
277 | ||
8550eb99 IM |
278 | static int __meminit |
279 | add_one_highpage_hotplug(struct page *page, unsigned long pfn) | |
05039b92 DH |
280 | { |
281 | free_new_highpage(page); | |
282 | totalram_pages++; | |
283 | #ifdef CONFIG_FLATMEM | |
284 | max_mapnr = max(pfn, max_mapnr); | |
285 | #endif | |
286 | num_physpages++; | |
8550eb99 | 287 | |
05039b92 DH |
288 | return 0; |
289 | } | |
290 | ||
291 | /* | |
292 | * Not currently handling the NUMA case. | |
293 | * Assuming single node and all memory that | |
294 | * has been added dynamically that would be | |
8550eb99 | 295 | * onlined here is in HIGHMEM. |
05039b92 | 296 | */ |
0e0be25d | 297 | void __meminit online_page(struct page *page) |
05039b92 DH |
298 | { |
299 | ClearPageReserved(page); | |
300 | add_one_highpage_hotplug(page, page_to_pfn(page)); | |
301 | } | |
302 | ||
8550eb99 | 303 | #ifndef CONFIG_NUMA |
1da177e4 LT |
304 | static void __init set_highmem_pages_init(int bad_ppro) |
305 | { | |
306 | int pfn; | |
8550eb99 | 307 | |
23be8c7d IM |
308 | for (pfn = highstart_pfn; pfn < highend_pfn; pfn++) { |
309 | /* | |
310 | * Holes under sparsemem might not have no mem_map[]: | |
311 | */ | |
312 | if (pfn_valid(pfn)) | |
313 | add_one_highpage_init(pfn_to_page(pfn), pfn, bad_ppro); | |
314 | } | |
1da177e4 LT |
315 | totalram_pages += totalhigh_pages; |
316 | } | |
8550eb99 | 317 | #endif /* !CONFIG_NUMA */ |
1da177e4 LT |
318 | |
319 | #else | |
8550eb99 IM |
320 | # define kmap_init() do { } while (0) |
321 | # define permanent_kmaps_init(pgd_base) do { } while (0) | |
322 | # define set_highmem_pages_init(bad_ppro) do { } while (0) | |
1da177e4 LT |
323 | #endif /* CONFIG_HIGHMEM */ |
324 | ||
c93c82bb | 325 | pteval_t __PAGE_KERNEL = _PAGE_KERNEL; |
129f6946 | 326 | EXPORT_SYMBOL(__PAGE_KERNEL); |
1da177e4 | 327 | |
8550eb99 | 328 | pteval_t __PAGE_KERNEL_EXEC = _PAGE_KERNEL_EXEC; |
1da177e4 | 329 | |
b239fb25 | 330 | void __init native_pagetable_setup_start(pgd_t *base) |
1da177e4 | 331 | { |
551889a6 IC |
332 | unsigned long pfn, va; |
333 | pgd_t *pgd; | |
334 | pud_t *pud; | |
335 | pmd_t *pmd; | |
336 | pte_t *pte; | |
b239fb25 JF |
337 | |
338 | /* | |
551889a6 IC |
339 | * Remove any mappings which extend past the end of physical |
340 | * memory from the boot time page table: | |
b239fb25 | 341 | */ |
551889a6 IC |
342 | for (pfn = max_low_pfn + 1; pfn < 1<<(32-PAGE_SHIFT); pfn++) { |
343 | va = PAGE_OFFSET + (pfn<<PAGE_SHIFT); | |
344 | pgd = base + pgd_index(va); | |
345 | if (!pgd_present(*pgd)) | |
346 | break; | |
347 | ||
348 | pud = pud_offset(pgd, va); | |
349 | pmd = pmd_offset(pud, va); | |
350 | if (!pmd_present(*pmd)) | |
351 | break; | |
352 | ||
353 | pte = pte_offset_kernel(pmd, va); | |
354 | if (!pte_present(*pte)) | |
355 | break; | |
356 | ||
357 | pte_clear(NULL, va, pte); | |
358 | } | |
6c435456 | 359 | paravirt_alloc_pd(&init_mm, __pa(base) >> PAGE_SHIFT); |
b239fb25 JF |
360 | } |
361 | ||
362 | void __init native_pagetable_setup_done(pgd_t *base) | |
363 | { | |
b239fb25 JF |
364 | } |
365 | ||
366 | /* | |
367 | * Build a proper pagetable for the kernel mappings. Up until this | |
368 | * point, we've been running on some set of pagetables constructed by | |
369 | * the boot process. | |
370 | * | |
371 | * If we're booting on native hardware, this will be a pagetable | |
551889a6 IC |
372 | * constructed in arch/x86/kernel/head_32.S. The root of the |
373 | * pagetable will be swapper_pg_dir. | |
b239fb25 JF |
374 | * |
375 | * If we're booting paravirtualized under a hypervisor, then there are | |
376 | * more options: we may already be running PAE, and the pagetable may | |
377 | * or may not be based in swapper_pg_dir. In any case, | |
378 | * paravirt_pagetable_setup_start() will set up swapper_pg_dir | |
379 | * appropriately for the rest of the initialization to work. | |
380 | * | |
381 | * In general, pagetable_init() assumes that the pagetable may already | |
382 | * be partially populated, and so it avoids stomping on any existing | |
383 | * mappings. | |
384 | */ | |
8550eb99 | 385 | static void __init pagetable_init(void) |
b239fb25 | 386 | { |
b239fb25 | 387 | pgd_t *pgd_base = swapper_pg_dir; |
8550eb99 | 388 | unsigned long vaddr, end; |
b239fb25 JF |
389 | |
390 | paravirt_pagetable_setup_start(pgd_base); | |
1da177e4 LT |
391 | |
392 | /* Enable PSE if available */ | |
b239fb25 | 393 | if (cpu_has_pse) |
1da177e4 | 394 | set_in_cr4(X86_CR4_PSE); |
1da177e4 LT |
395 | |
396 | /* Enable PGE if available */ | |
397 | if (cpu_has_pge) { | |
398 | set_in_cr4(X86_CR4_PGE); | |
399 | __PAGE_KERNEL |= _PAGE_GLOBAL; | |
400 | __PAGE_KERNEL_EXEC |= _PAGE_GLOBAL; | |
401 | } | |
402 | ||
403 | kernel_physical_mapping_init(pgd_base); | |
404 | remap_numa_kva(); | |
405 | ||
406 | /* | |
407 | * Fixed mappings, only the page table structure has to be | |
408 | * created - mappings will be set by set_fixmap(): | |
409 | */ | |
beacfaac | 410 | early_ioremap_clear(); |
1da177e4 | 411 | vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; |
b239fb25 JF |
412 | end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK; |
413 | page_table_range_init(vaddr, end, pgd_base); | |
beacfaac | 414 | early_ioremap_reset(); |
1da177e4 LT |
415 | |
416 | permanent_kmaps_init(pgd_base); | |
417 | ||
b239fb25 | 418 | paravirt_pagetable_setup_done(pgd_base); |
1da177e4 LT |
419 | } |
420 | ||
a6eb84bc | 421 | #ifdef CONFIG_ACPI_SLEEP |
1da177e4 | 422 | /* |
a6eb84bc | 423 | * ACPI suspend needs this for resume, because things like the intel-agp |
1da177e4 LT |
424 | * driver might have split up a kernel 4MB mapping. |
425 | */ | |
a6eb84bc | 426 | char swsusp_pg_dir[PAGE_SIZE] |
8550eb99 | 427 | __attribute__ ((aligned(PAGE_SIZE))); |
1da177e4 LT |
428 | |
429 | static inline void save_pg_dir(void) | |
430 | { | |
431 | memcpy(swsusp_pg_dir, swapper_pg_dir, PAGE_SIZE); | |
432 | } | |
a6eb84bc | 433 | #else /* !CONFIG_ACPI_SLEEP */ |
1da177e4 LT |
434 | static inline void save_pg_dir(void) |
435 | { | |
436 | } | |
a6eb84bc | 437 | #endif /* !CONFIG_ACPI_SLEEP */ |
1da177e4 | 438 | |
8550eb99 | 439 | void zap_low_mappings(void) |
1da177e4 LT |
440 | { |
441 | int i; | |
442 | ||
443 | save_pg_dir(); | |
444 | ||
445 | /* | |
446 | * Zap initial low-memory mappings. | |
447 | * | |
448 | * Note that "pgd_clear()" doesn't do it for | |
449 | * us, because pgd_clear() is a no-op on i386. | |
450 | */ | |
8550eb99 | 451 | for (i = 0; i < USER_PTRS_PER_PGD; i++) { |
1da177e4 LT |
452 | #ifdef CONFIG_X86_PAE |
453 | set_pgd(swapper_pg_dir+i, __pgd(1 + __pa(empty_zero_page))); | |
454 | #else | |
455 | set_pgd(swapper_pg_dir+i, __pgd(0)); | |
456 | #endif | |
8550eb99 | 457 | } |
1da177e4 LT |
458 | flush_tlb_all(); |
459 | } | |
460 | ||
8550eb99 | 461 | int nx_enabled; |
d5321abe | 462 | |
6fdc05d4 JF |
463 | pteval_t __supported_pte_mask __read_mostly = ~_PAGE_NX; |
464 | EXPORT_SYMBOL_GPL(__supported_pte_mask); | |
465 | ||
d5321abe JB |
466 | #ifdef CONFIG_X86_PAE |
467 | ||
8550eb99 | 468 | static int disable_nx __initdata; |
1da177e4 LT |
469 | |
470 | /* | |
471 | * noexec = on|off | |
472 | * | |
473 | * Control non executable mappings. | |
474 | * | |
475 | * on Enable | |
476 | * off Disable | |
477 | */ | |
1a3f239d | 478 | static int __init noexec_setup(char *str) |
1da177e4 | 479 | { |
1a3f239d RR |
480 | if (!str || !strcmp(str, "on")) { |
481 | if (cpu_has_nx) { | |
482 | __supported_pte_mask |= _PAGE_NX; | |
483 | disable_nx = 0; | |
484 | } | |
8550eb99 IM |
485 | } else { |
486 | if (!strcmp(str, "off")) { | |
487 | disable_nx = 1; | |
488 | __supported_pte_mask &= ~_PAGE_NX; | |
489 | } else { | |
490 | return -EINVAL; | |
491 | } | |
492 | } | |
1a3f239d RR |
493 | |
494 | return 0; | |
1da177e4 | 495 | } |
1a3f239d | 496 | early_param("noexec", noexec_setup); |
1da177e4 | 497 | |
1da177e4 LT |
498 | static void __init set_nx(void) |
499 | { | |
500 | unsigned int v[4], l, h; | |
501 | ||
502 | if (cpu_has_pae && (cpuid_eax(0x80000000) > 0x80000001)) { | |
503 | cpuid(0x80000001, &v[0], &v[1], &v[2], &v[3]); | |
8550eb99 | 504 | |
1da177e4 LT |
505 | if ((v[3] & (1 << 20)) && !disable_nx) { |
506 | rdmsr(MSR_EFER, l, h); | |
507 | l |= EFER_NX; | |
508 | wrmsr(MSR_EFER, l, h); | |
509 | nx_enabled = 1; | |
510 | __supported_pte_mask |= _PAGE_NX; | |
511 | } | |
512 | } | |
513 | } | |
1da177e4 LT |
514 | #endif |
515 | ||
516 | /* | |
517 | * paging_init() sets up the page tables - note that the first 8MB are | |
518 | * already mapped by head.S. | |
519 | * | |
520 | * This routines also unmaps the page at virtual kernel address 0, so | |
521 | * that we can trap those pesky NULL-reference errors in the kernel. | |
522 | */ | |
523 | void __init paging_init(void) | |
524 | { | |
525 | #ifdef CONFIG_X86_PAE | |
526 | set_nx(); | |
527 | if (nx_enabled) | |
d7d119d7 | 528 | printk(KERN_INFO "NX (Execute Disable) protection: active\n"); |
1da177e4 | 529 | #endif |
1da177e4 LT |
530 | pagetable_init(); |
531 | ||
532 | load_cr3(swapper_pg_dir); | |
533 | ||
1da177e4 LT |
534 | __flush_tlb_all(); |
535 | ||
536 | kmap_init(); | |
537 | } | |
538 | ||
539 | /* | |
540 | * Test if the WP bit works in supervisor mode. It isn't supported on 386's | |
541 | * and also on some strange 486's (NexGen etc.). All 586+'s are OK. This | |
542 | * used to involve black magic jumps to work around some nasty CPU bugs, | |
543 | * but fortunately the switch to using exceptions got rid of all that. | |
544 | */ | |
1da177e4 LT |
545 | static void __init test_wp_bit(void) |
546 | { | |
d7d119d7 IM |
547 | printk(KERN_INFO |
548 | "Checking if this processor honours the WP bit even in supervisor mode..."); | |
1da177e4 LT |
549 | |
550 | /* Any page-aligned address will do, the test is non-destructive */ | |
551 | __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_READONLY); | |
552 | boot_cpu_data.wp_works_ok = do_test_wp_bit(); | |
553 | clear_fixmap(FIX_WP_TEST); | |
554 | ||
555 | if (!boot_cpu_data.wp_works_ok) { | |
d7d119d7 | 556 | printk(KERN_CONT "No.\n"); |
1da177e4 | 557 | #ifdef CONFIG_X86_WP_WORKS_OK |
d7d119d7 IM |
558 | panic( |
559 | "This kernel doesn't support CPU's with broken WP. Recompile it for a 386!"); | |
1da177e4 LT |
560 | #endif |
561 | } else { | |
d7d119d7 | 562 | printk(KERN_CONT "Ok.\n"); |
1da177e4 LT |
563 | } |
564 | } | |
565 | ||
8550eb99 | 566 | static struct kcore_list kcore_mem, kcore_vmalloc; |
1da177e4 LT |
567 | |
568 | void __init mem_init(void) | |
569 | { | |
1da177e4 | 570 | int codesize, reservedpages, datasize, initsize; |
8550eb99 | 571 | int tmp, bad_ppro; |
1da177e4 | 572 | |
05b79bdc | 573 | #ifdef CONFIG_FLATMEM |
8d8f3cbe | 574 | BUG_ON(!mem_map); |
1da177e4 | 575 | #endif |
1da177e4 LT |
576 | bad_ppro = ppro_with_ram_bug(); |
577 | ||
578 | #ifdef CONFIG_HIGHMEM | |
579 | /* check that fixmap and pkmap do not overlap */ | |
d7d119d7 IM |
580 | if (PKMAP_BASE + LAST_PKMAP*PAGE_SIZE >= FIXADDR_START) { |
581 | printk(KERN_ERR | |
582 | "fixmap and kmap areas overlap - this will crash\n"); | |
1da177e4 | 583 | printk(KERN_ERR "pkstart: %lxh pkend: %lxh fixstart %lxh\n", |
d7d119d7 IM |
584 | PKMAP_BASE, PKMAP_BASE + LAST_PKMAP*PAGE_SIZE, |
585 | FIXADDR_START); | |
1da177e4 LT |
586 | BUG(); |
587 | } | |
588 | #endif | |
1da177e4 LT |
589 | /* this will put all low memory onto the freelists */ |
590 | totalram_pages += free_all_bootmem(); | |
591 | ||
592 | reservedpages = 0; | |
593 | for (tmp = 0; tmp < max_low_pfn; tmp++) | |
594 | /* | |
8550eb99 | 595 | * Only count reserved RAM pages: |
1da177e4 LT |
596 | */ |
597 | if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp))) | |
598 | reservedpages++; | |
599 | ||
600 | set_highmem_pages_init(bad_ppro); | |
601 | ||
602 | codesize = (unsigned long) &_etext - (unsigned long) &_text; | |
603 | datasize = (unsigned long) &_edata - (unsigned long) &_etext; | |
604 | initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; | |
605 | ||
8550eb99 IM |
606 | kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT); |
607 | kclist_add(&kcore_vmalloc, (void *)VMALLOC_START, | |
1da177e4 LT |
608 | VMALLOC_END-VMALLOC_START); |
609 | ||
8550eb99 IM |
610 | printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, " |
611 | "%dk reserved, %dk data, %dk init, %ldk highmem)\n", | |
1da177e4 LT |
612 | (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), |
613 | num_physpages << (PAGE_SHIFT-10), | |
614 | codesize >> 10, | |
615 | reservedpages << (PAGE_SHIFT-10), | |
616 | datasize >> 10, | |
617 | initsize >> 10, | |
618 | (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)) | |
619 | ); | |
620 | ||
052e7994 | 621 | #if 1 /* double-sanity-check paranoia */ |
d7d119d7 | 622 | printk(KERN_INFO "virtual kernel memory layout:\n" |
8550eb99 | 623 | " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n" |
052e7994 | 624 | #ifdef CONFIG_HIGHMEM |
8550eb99 | 625 | " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n" |
052e7994 | 626 | #endif |
8550eb99 IM |
627 | " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n" |
628 | " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n" | |
629 | " .init : 0x%08lx - 0x%08lx (%4ld kB)\n" | |
630 | " .data : 0x%08lx - 0x%08lx (%4ld kB)\n" | |
631 | " .text : 0x%08lx - 0x%08lx (%4ld kB)\n", | |
632 | FIXADDR_START, FIXADDR_TOP, | |
633 | (FIXADDR_TOP - FIXADDR_START) >> 10, | |
052e7994 JF |
634 | |
635 | #ifdef CONFIG_HIGHMEM | |
8550eb99 IM |
636 | PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE, |
637 | (LAST_PKMAP*PAGE_SIZE) >> 10, | |
052e7994 JF |
638 | #endif |
639 | ||
8550eb99 IM |
640 | VMALLOC_START, VMALLOC_END, |
641 | (VMALLOC_END - VMALLOC_START) >> 20, | |
052e7994 | 642 | |
8550eb99 IM |
643 | (unsigned long)__va(0), (unsigned long)high_memory, |
644 | ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20, | |
052e7994 | 645 | |
8550eb99 IM |
646 | (unsigned long)&__init_begin, (unsigned long)&__init_end, |
647 | ((unsigned long)&__init_end - | |
648 | (unsigned long)&__init_begin) >> 10, | |
052e7994 | 649 | |
8550eb99 IM |
650 | (unsigned long)&_etext, (unsigned long)&_edata, |
651 | ((unsigned long)&_edata - (unsigned long)&_etext) >> 10, | |
052e7994 | 652 | |
8550eb99 IM |
653 | (unsigned long)&_text, (unsigned long)&_etext, |
654 | ((unsigned long)&_etext - (unsigned long)&_text) >> 10); | |
052e7994 JF |
655 | |
656 | #ifdef CONFIG_HIGHMEM | |
8550eb99 IM |
657 | BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START); |
658 | BUG_ON(VMALLOC_END > PKMAP_BASE); | |
052e7994 | 659 | #endif |
8550eb99 IM |
660 | BUG_ON(VMALLOC_START > VMALLOC_END); |
661 | BUG_ON((unsigned long)high_memory > VMALLOC_START); | |
052e7994 JF |
662 | #endif /* double-sanity-check paranoia */ |
663 | ||
1da177e4 LT |
664 | if (boot_cpu_data.wp_works_ok < 0) |
665 | test_wp_bit(); | |
666 | ||
76ebd054 TG |
667 | cpa_init(); |
668 | ||
1da177e4 LT |
669 | /* |
670 | * Subtle. SMP is doing it's boot stuff late (because it has to | |
671 | * fork idle threads) - but it also needs low mappings for the | |
672 | * protected-mode entry to work. We zap these entries only after | |
673 | * the WP-bit has been tested. | |
674 | */ | |
675 | #ifndef CONFIG_SMP | |
676 | zap_low_mappings(); | |
677 | #endif | |
678 | } | |
679 | ||
ad8f5797 | 680 | #ifdef CONFIG_MEMORY_HOTPLUG |
bc02af93 | 681 | int arch_add_memory(int nid, u64 start, u64 size) |
05039b92 | 682 | { |
7c7e9425 | 683 | struct pglist_data *pgdata = NODE_DATA(nid); |
776ed98b | 684 | struct zone *zone = pgdata->node_zones + ZONE_HIGHMEM; |
05039b92 DH |
685 | unsigned long start_pfn = start >> PAGE_SHIFT; |
686 | unsigned long nr_pages = size >> PAGE_SHIFT; | |
687 | ||
688 | return __add_pages(zone, start_pfn, nr_pages); | |
689 | } | |
9d99aaa3 | 690 | #endif |
05039b92 | 691 | |
1da177e4 LT |
692 | /* |
693 | * This function cannot be __init, since exceptions don't work in that | |
694 | * section. Put this after the callers, so that it cannot be inlined. | |
695 | */ | |
8550eb99 | 696 | static noinline int do_test_wp_bit(void) |
1da177e4 LT |
697 | { |
698 | char tmp_reg; | |
699 | int flag; | |
700 | ||
701 | __asm__ __volatile__( | |
8550eb99 IM |
702 | " movb %0, %1 \n" |
703 | "1: movb %1, %0 \n" | |
704 | " xorl %2, %2 \n" | |
1da177e4 | 705 | "2: \n" |
f832ff18 | 706 | _ASM_EXTABLE(1b,2b) |
1da177e4 LT |
707 | :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)), |
708 | "=q" (tmp_reg), | |
709 | "=r" (flag) | |
710 | :"2" (1) | |
711 | :"memory"); | |
8550eb99 | 712 | |
1da177e4 LT |
713 | return flag; |
714 | } | |
715 | ||
63aaf308 | 716 | #ifdef CONFIG_DEBUG_RODATA |
edeed305 AV |
717 | const int rodata_test_data = 0xC3; |
718 | EXPORT_SYMBOL_GPL(rodata_test_data); | |
63aaf308 | 719 | |
63aaf308 AV |
720 | void mark_rodata_ro(void) |
721 | { | |
6fb14755 JB |
722 | unsigned long start = PFN_ALIGN(_text); |
723 | unsigned long size = PFN_ALIGN(_etext) - start; | |
63aaf308 | 724 | |
602033ed LT |
725 | #ifndef CONFIG_KPROBES |
726 | #ifdef CONFIG_HOTPLUG_CPU | |
727 | /* It must still be possible to apply SMP alternatives. */ | |
728 | if (num_possible_cpus() <= 1) | |
729 | #endif | |
730 | { | |
6d238cc4 | 731 | set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); |
d7d119d7 IM |
732 | printk(KERN_INFO "Write protecting the kernel text: %luk\n", |
733 | size >> 10); | |
0c42f392 AK |
734 | |
735 | #ifdef CONFIG_CPA_DEBUG | |
d7d119d7 IM |
736 | printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n", |
737 | start, start+size); | |
6d238cc4 | 738 | set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT); |
0c42f392 | 739 | |
d7d119d7 | 740 | printk(KERN_INFO "Testing CPA: write protecting again\n"); |
6d238cc4 | 741 | set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT); |
0c42f392 | 742 | #endif |
602033ed LT |
743 | } |
744 | #endif | |
6fb14755 JB |
745 | start += size; |
746 | size = (unsigned long)__end_rodata - start; | |
6d238cc4 | 747 | set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); |
d7d119d7 IM |
748 | printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", |
749 | size >> 10); | |
edeed305 | 750 | rodata_test(); |
63aaf308 | 751 | |
0c42f392 | 752 | #ifdef CONFIG_CPA_DEBUG |
d7d119d7 | 753 | printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size); |
6d238cc4 | 754 | set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT); |
0c42f392 | 755 | |
d7d119d7 | 756 | printk(KERN_INFO "Testing CPA: write protecting again\n"); |
6d238cc4 | 757 | set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); |
0c42f392 | 758 | #endif |
63aaf308 AV |
759 | } |
760 | #endif | |
761 | ||
9a0b5817 GH |
762 | void free_init_pages(char *what, unsigned long begin, unsigned long end) |
763 | { | |
ee01f112 IM |
764 | #ifdef CONFIG_DEBUG_PAGEALLOC |
765 | /* | |
766 | * If debugging page accesses then do not free this memory but | |
767 | * mark them not present - any buggy init-section access will | |
768 | * create a kernel page fault: | |
769 | */ | |
770 | printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n", | |
771 | begin, PAGE_ALIGN(end)); | |
772 | set_memory_np(begin, (end - begin) >> PAGE_SHIFT); | |
773 | #else | |
86f03989 IM |
774 | unsigned long addr; |
775 | ||
3c1df68b AV |
776 | /* |
777 | * We just marked the kernel text read only above, now that | |
778 | * we are going to free part of that, we need to make that | |
779 | * writeable first. | |
780 | */ | |
781 | set_memory_rw(begin, (end - begin) >> PAGE_SHIFT); | |
782 | ||
9a0b5817 | 783 | for (addr = begin; addr < end; addr += PAGE_SIZE) { |
e3ebadd9 LT |
784 | ClearPageReserved(virt_to_page(addr)); |
785 | init_page_count(virt_to_page(addr)); | |
786 | memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE); | |
787 | free_page(addr); | |
9a0b5817 GH |
788 | totalram_pages++; |
789 | } | |
6fb14755 | 790 | printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10); |
ee01f112 | 791 | #endif |
9a0b5817 GH |
792 | } |
793 | ||
794 | void free_initmem(void) | |
795 | { | |
796 | free_init_pages("unused kernel memory", | |
e3ebadd9 LT |
797 | (unsigned long)(&__init_begin), |
798 | (unsigned long)(&__init_end)); | |
9a0b5817 | 799 | } |
63aaf308 | 800 | |
1da177e4 LT |
801 | #ifdef CONFIG_BLK_DEV_INITRD |
802 | void free_initrd_mem(unsigned long start, unsigned long end) | |
803 | { | |
e3ebadd9 | 804 | free_init_pages("initrd memory", start, end); |
1da177e4 LT |
805 | } |
806 | #endif |