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Commit | Line | Data |
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1da177e4 | 1 | /* |
1da177e4 LT |
2 | * |
3 | * Copyright (C) 1995 Linus Torvalds | |
4 | * | |
5 | * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 | |
6 | */ | |
7 | ||
1da177e4 LT |
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> | |
6fb14755 | 24 | #include <linux/pfn.h> |
c9cf5528 | 25 | #include <linux/poison.h> |
1da177e4 LT |
26 | #include <linux/bootmem.h> |
27 | #include <linux/slab.h> | |
28 | #include <linux/proc_fs.h> | |
05039b92 | 29 | #include <linux/memory_hotplug.h> |
27d99f7e | 30 | #include <linux/initrd.h> |
55b2355e | 31 | #include <linux/cpumask.h> |
1da177e4 | 32 | |
f832ff18 | 33 | #include <asm/asm.h> |
1da177e4 LT |
34 | #include <asm/processor.h> |
35 | #include <asm/system.h> | |
36 | #include <asm/uaccess.h> | |
37 | #include <asm/pgtable.h> | |
38 | #include <asm/dma.h> | |
39 | #include <asm/fixmap.h> | |
40 | #include <asm/e820.h> | |
41 | #include <asm/apic.h> | |
8550eb99 | 42 | #include <asm/bugs.h> |
1da177e4 LT |
43 | #include <asm/tlb.h> |
44 | #include <asm/tlbflush.h> | |
a5a19c63 | 45 | #include <asm/pgalloc.h> |
1da177e4 | 46 | #include <asm/sections.h> |
b239fb25 | 47 | #include <asm/paravirt.h> |
551889a6 | 48 | #include <asm/setup.h> |
7bfeab9a | 49 | #include <asm/cacheflush.h> |
1da177e4 LT |
50 | |
51 | unsigned int __VMALLOC_RESERVE = 128 << 20; | |
52 | ||
67794292 | 53 | unsigned long max_pfn_mapped; |
7d1116a9 | 54 | |
1da177e4 LT |
55 | DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); |
56 | unsigned long highstart_pfn, highend_pfn; | |
57 | ||
8550eb99 | 58 | static noinline int do_test_wp_bit(void); |
1da177e4 LT |
59 | |
60 | /* | |
61 | * Creates a middle page table and puts a pointer to it in the | |
62 | * given global directory entry. This only returns the gd entry | |
63 | * in non-PAE compilation mode, since the middle layer is folded. | |
64 | */ | |
65 | static pmd_t * __init one_md_table_init(pgd_t *pgd) | |
66 | { | |
67 | pud_t *pud; | |
68 | pmd_t *pmd_table; | |
8550eb99 | 69 | |
1da177e4 | 70 | #ifdef CONFIG_X86_PAE |
b239fb25 JF |
71 | if (!(pgd_val(*pgd) & _PAGE_PRESENT)) { |
72 | pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE); | |
73 | ||
6944a9c8 | 74 | paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT); |
b239fb25 JF |
75 | set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT)); |
76 | pud = pud_offset(pgd, 0); | |
8550eb99 | 77 | BUG_ON(pmd_table != pmd_offset(pud, 0)); |
b239fb25 JF |
78 | } |
79 | #endif | |
1da177e4 LT |
80 | pud = pud_offset(pgd, 0); |
81 | pmd_table = pmd_offset(pud, 0); | |
8550eb99 | 82 | |
1da177e4 LT |
83 | return pmd_table; |
84 | } | |
85 | ||
86 | /* | |
87 | * Create a page table and place a pointer to it in a middle page | |
8550eb99 | 88 | * directory entry: |
1da177e4 LT |
89 | */ |
90 | static pte_t * __init one_page_table_init(pmd_t *pmd) | |
91 | { | |
b239fb25 | 92 | if (!(pmd_val(*pmd) & _PAGE_PRESENT)) { |
509a80c4 IM |
93 | pte_t *page_table = NULL; |
94 | ||
95 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
96 | page_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE); | |
97 | #endif | |
8550eb99 | 98 | if (!page_table) { |
509a80c4 IM |
99 | page_table = |
100 | (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE); | |
8550eb99 | 101 | } |
b239fb25 | 102 | |
6944a9c8 | 103 | paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT); |
1da177e4 | 104 | set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE)); |
b239fb25 | 105 | BUG_ON(page_table != pte_offset_kernel(pmd, 0)); |
1da177e4 | 106 | } |
509a80c4 | 107 | |
1da177e4 LT |
108 | return pte_offset_kernel(pmd, 0); |
109 | } | |
110 | ||
111 | /* | |
8550eb99 | 112 | * This function initializes a certain range of kernel virtual memory |
1da177e4 LT |
113 | * with new bootmem page tables, everywhere page tables are missing in |
114 | * the given range. | |
8550eb99 IM |
115 | * |
116 | * NOTE: The pagetables are allocated contiguous on the physical space | |
117 | * so we can cache the place of the first one and move around without | |
1da177e4 LT |
118 | * checking the pgd every time. |
119 | */ | |
8550eb99 IM |
120 | static void __init |
121 | page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base) | |
1da177e4 | 122 | { |
1da177e4 LT |
123 | int pgd_idx, pmd_idx; |
124 | unsigned long vaddr; | |
8550eb99 IM |
125 | pgd_t *pgd; |
126 | pmd_t *pmd; | |
1da177e4 LT |
127 | |
128 | vaddr = start; | |
129 | pgd_idx = pgd_index(vaddr); | |
130 | pmd_idx = pmd_index(vaddr); | |
131 | pgd = pgd_base + pgd_idx; | |
132 | ||
133 | for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) { | |
b239fb25 JF |
134 | pmd = one_md_table_init(pgd); |
135 | pmd = pmd + pmd_index(vaddr); | |
8550eb99 IM |
136 | for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end); |
137 | pmd++, pmd_idx++) { | |
b239fb25 | 138 | one_page_table_init(pmd); |
1da177e4 LT |
139 | |
140 | vaddr += PMD_SIZE; | |
141 | } | |
142 | pmd_idx = 0; | |
143 | } | |
144 | } | |
145 | ||
146 | static inline int is_kernel_text(unsigned long addr) | |
147 | { | |
148 | if (addr >= PAGE_OFFSET && addr <= (unsigned long)__init_end) | |
149 | return 1; | |
150 | return 0; | |
151 | } | |
152 | ||
153 | /* | |
8550eb99 IM |
154 | * This maps the physical memory to kernel virtual address space, a total |
155 | * of max_low_pfn pages, by creating page tables starting from address | |
156 | * PAGE_OFFSET: | |
1da177e4 LT |
157 | */ |
158 | static void __init kernel_physical_mapping_init(pgd_t *pgd_base) | |
159 | { | |
8550eb99 | 160 | int pgd_idx, pmd_idx, pte_ofs; |
1da177e4 LT |
161 | unsigned long pfn; |
162 | pgd_t *pgd; | |
163 | pmd_t *pmd; | |
164 | pte_t *pte; | |
1da177e4 LT |
165 | |
166 | pgd_idx = pgd_index(PAGE_OFFSET); | |
167 | pgd = pgd_base + pgd_idx; | |
168 | pfn = 0; | |
169 | ||
170 | for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) { | |
171 | pmd = one_md_table_init(pgd); | |
172 | if (pfn >= max_low_pfn) | |
173 | continue; | |
8550eb99 | 174 | |
f3f20de8 JF |
175 | for (pmd_idx = 0; |
176 | pmd_idx < PTRS_PER_PMD && pfn < max_low_pfn; | |
177 | pmd++, pmd_idx++) { | |
8550eb99 | 178 | unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET; |
1da177e4 | 179 | |
8550eb99 IM |
180 | /* |
181 | * Map with big pages if possible, otherwise | |
182 | * create normal page tables: | |
f5c24a7f AK |
183 | * |
184 | * Don't use a large page for the first 2/4MB of memory | |
185 | * because there are often fixed size MTRRs in there | |
186 | * and overlapping MTRRs into large pages can cause | |
187 | * slowdowns. | |
8550eb99 | 188 | */ |
f5c24a7f | 189 | if (cpu_has_pse && !(pgd_idx == 0 && pmd_idx == 0)) { |
8550eb99 | 190 | unsigned int addr2; |
f3f20de8 JF |
191 | pgprot_t prot = PAGE_KERNEL_LARGE; |
192 | ||
8550eb99 | 193 | addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE + |
f3f20de8 JF |
194 | PAGE_OFFSET + PAGE_SIZE-1; |
195 | ||
8550eb99 IM |
196 | if (is_kernel_text(addr) || |
197 | is_kernel_text(addr2)) | |
f3f20de8 JF |
198 | prot = PAGE_KERNEL_LARGE_EXEC; |
199 | ||
200 | set_pmd(pmd, pfn_pmd(pfn, prot)); | |
b239fb25 | 201 | |
1da177e4 | 202 | pfn += PTRS_PER_PTE; |
67794292 | 203 | max_pfn_mapped = pfn; |
8550eb99 IM |
204 | continue; |
205 | } | |
206 | pte = one_page_table_init(pmd); | |
1da177e4 | 207 | |
8550eb99 IM |
208 | for (pte_ofs = 0; |
209 | pte_ofs < PTRS_PER_PTE && pfn < max_low_pfn; | |
210 | pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) { | |
211 | pgprot_t prot = PAGE_KERNEL; | |
f3f20de8 | 212 | |
8550eb99 IM |
213 | if (is_kernel_text(addr)) |
214 | prot = PAGE_KERNEL_EXEC; | |
f3f20de8 | 215 | |
8550eb99 | 216 | set_pte(pte, pfn_pte(pfn, prot)); |
1da177e4 | 217 | } |
67794292 | 218 | max_pfn_mapped = pfn; |
1da177e4 LT |
219 | } |
220 | } | |
221 | } | |
222 | ||
223 | static inline int page_kills_ppro(unsigned long pagenr) | |
224 | { | |
225 | if (pagenr >= 0x70000 && pagenr <= 0x7003F) | |
226 | return 1; | |
227 | return 0; | |
228 | } | |
229 | ||
ae531c26 AV |
230 | /* |
231 | * devmem_is_allowed() checks to see if /dev/mem access to a certain address | |
232 | * is valid. The argument is a physical page number. | |
233 | * | |
234 | * | |
235 | * On x86, access has to be given to the first megabyte of ram because that area | |
236 | * contains bios code and data regions used by X and dosemu and similar apps. | |
237 | * Access has to be given to non-kernel-ram areas as well, these contain the PCI | |
238 | * mmio resources as well as potential bios/acpi data regions. | |
239 | */ | |
240 | int devmem_is_allowed(unsigned long pagenr) | |
241 | { | |
242 | if (pagenr <= 256) | |
243 | return 1; | |
244 | if (!page_is_ram(pagenr)) | |
245 | return 1; | |
246 | return 0; | |
247 | } | |
248 | ||
1da177e4 LT |
249 | #ifdef CONFIG_HIGHMEM |
250 | pte_t *kmap_pte; | |
251 | pgprot_t kmap_prot; | |
252 | ||
8550eb99 IM |
253 | static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr) |
254 | { | |
255 | return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), | |
256 | vaddr), vaddr), vaddr); | |
257 | } | |
1da177e4 LT |
258 | |
259 | static void __init kmap_init(void) | |
260 | { | |
261 | unsigned long kmap_vstart; | |
262 | ||
8550eb99 IM |
263 | /* |
264 | * Cache the first kmap pte: | |
265 | */ | |
1da177e4 LT |
266 | kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN); |
267 | kmap_pte = kmap_get_fixmap_pte(kmap_vstart); | |
268 | ||
269 | kmap_prot = PAGE_KERNEL; | |
270 | } | |
271 | ||
272 | static void __init permanent_kmaps_init(pgd_t *pgd_base) | |
273 | { | |
8550eb99 | 274 | unsigned long vaddr; |
1da177e4 LT |
275 | pgd_t *pgd; |
276 | pud_t *pud; | |
277 | pmd_t *pmd; | |
278 | pte_t *pte; | |
1da177e4 LT |
279 | |
280 | vaddr = PKMAP_BASE; | |
281 | page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base); | |
282 | ||
283 | pgd = swapper_pg_dir + pgd_index(vaddr); | |
284 | pud = pud_offset(pgd, vaddr); | |
285 | pmd = pmd_offset(pud, vaddr); | |
286 | pte = pte_offset_kernel(pmd, vaddr); | |
8550eb99 | 287 | pkmap_page_table = pte; |
1da177e4 LT |
288 | } |
289 | ||
c09b4240 | 290 | static void __meminit free_new_highpage(struct page *page) |
05039b92 | 291 | { |
7835e98b | 292 | init_page_count(page); |
05039b92 DH |
293 | __free_page(page); |
294 | totalhigh_pages++; | |
295 | } | |
296 | ||
297 | void __init add_one_highpage_init(struct page *page, int pfn, int bad_ppro) | |
1da177e4 LT |
298 | { |
299 | if (page_is_ram(pfn) && !(bad_ppro && page_kills_ppro(pfn))) { | |
300 | ClearPageReserved(page); | |
05039b92 | 301 | free_new_highpage(page); |
1da177e4 LT |
302 | } else |
303 | SetPageReserved(page); | |
304 | } | |
305 | ||
8550eb99 IM |
306 | static int __meminit |
307 | add_one_highpage_hotplug(struct page *page, unsigned long pfn) | |
05039b92 DH |
308 | { |
309 | free_new_highpage(page); | |
310 | totalram_pages++; | |
311 | #ifdef CONFIG_FLATMEM | |
312 | max_mapnr = max(pfn, max_mapnr); | |
313 | #endif | |
314 | num_physpages++; | |
8550eb99 | 315 | |
05039b92 DH |
316 | return 0; |
317 | } | |
318 | ||
319 | /* | |
320 | * Not currently handling the NUMA case. | |
321 | * Assuming single node and all memory that | |
322 | * has been added dynamically that would be | |
8550eb99 | 323 | * onlined here is in HIGHMEM. |
05039b92 | 324 | */ |
0e0be25d | 325 | void __meminit online_page(struct page *page) |
05039b92 DH |
326 | { |
327 | ClearPageReserved(page); | |
328 | add_one_highpage_hotplug(page, page_to_pfn(page)); | |
329 | } | |
330 | ||
8550eb99 | 331 | #ifndef CONFIG_NUMA |
1da177e4 LT |
332 | static void __init set_highmem_pages_init(int bad_ppro) |
333 | { | |
334 | int pfn; | |
8550eb99 | 335 | |
23be8c7d IM |
336 | for (pfn = highstart_pfn; pfn < highend_pfn; pfn++) { |
337 | /* | |
338 | * Holes under sparsemem might not have no mem_map[]: | |
339 | */ | |
340 | if (pfn_valid(pfn)) | |
341 | add_one_highpage_init(pfn_to_page(pfn), pfn, bad_ppro); | |
342 | } | |
1da177e4 LT |
343 | totalram_pages += totalhigh_pages; |
344 | } | |
8550eb99 | 345 | #endif /* !CONFIG_NUMA */ |
1da177e4 LT |
346 | |
347 | #else | |
8550eb99 IM |
348 | # define kmap_init() do { } while (0) |
349 | # define permanent_kmaps_init(pgd_base) do { } while (0) | |
350 | # define set_highmem_pages_init(bad_ppro) do { } while (0) | |
1da177e4 LT |
351 | #endif /* CONFIG_HIGHMEM */ |
352 | ||
c93c82bb | 353 | pteval_t __PAGE_KERNEL = _PAGE_KERNEL; |
129f6946 | 354 | EXPORT_SYMBOL(__PAGE_KERNEL); |
1da177e4 | 355 | |
8550eb99 | 356 | pteval_t __PAGE_KERNEL_EXEC = _PAGE_KERNEL_EXEC; |
1da177e4 | 357 | |
b239fb25 | 358 | void __init native_pagetable_setup_start(pgd_t *base) |
1da177e4 | 359 | { |
551889a6 IC |
360 | unsigned long pfn, va; |
361 | pgd_t *pgd; | |
362 | pud_t *pud; | |
363 | pmd_t *pmd; | |
364 | pte_t *pte; | |
b239fb25 JF |
365 | |
366 | /* | |
551889a6 IC |
367 | * Remove any mappings which extend past the end of physical |
368 | * memory from the boot time page table: | |
b239fb25 | 369 | */ |
551889a6 IC |
370 | for (pfn = max_low_pfn + 1; pfn < 1<<(32-PAGE_SHIFT); pfn++) { |
371 | va = PAGE_OFFSET + (pfn<<PAGE_SHIFT); | |
372 | pgd = base + pgd_index(va); | |
373 | if (!pgd_present(*pgd)) | |
374 | break; | |
375 | ||
376 | pud = pud_offset(pgd, va); | |
377 | pmd = pmd_offset(pud, va); | |
378 | if (!pmd_present(*pmd)) | |
379 | break; | |
380 | ||
381 | pte = pte_offset_kernel(pmd, va); | |
382 | if (!pte_present(*pte)) | |
383 | break; | |
384 | ||
385 | pte_clear(NULL, va, pte); | |
386 | } | |
6944a9c8 | 387 | paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT); |
b239fb25 JF |
388 | } |
389 | ||
390 | void __init native_pagetable_setup_done(pgd_t *base) | |
391 | { | |
b239fb25 JF |
392 | } |
393 | ||
394 | /* | |
395 | * Build a proper pagetable for the kernel mappings. Up until this | |
396 | * point, we've been running on some set of pagetables constructed by | |
397 | * the boot process. | |
398 | * | |
399 | * If we're booting on native hardware, this will be a pagetable | |
551889a6 IC |
400 | * constructed in arch/x86/kernel/head_32.S. The root of the |
401 | * pagetable will be swapper_pg_dir. | |
b239fb25 JF |
402 | * |
403 | * If we're booting paravirtualized under a hypervisor, then there are | |
404 | * more options: we may already be running PAE, and the pagetable may | |
405 | * or may not be based in swapper_pg_dir. In any case, | |
406 | * paravirt_pagetable_setup_start() will set up swapper_pg_dir | |
407 | * appropriately for the rest of the initialization to work. | |
408 | * | |
409 | * In general, pagetable_init() assumes that the pagetable may already | |
410 | * be partially populated, and so it avoids stomping on any existing | |
411 | * mappings. | |
412 | */ | |
8550eb99 | 413 | static void __init pagetable_init(void) |
b239fb25 | 414 | { |
b239fb25 | 415 | pgd_t *pgd_base = swapper_pg_dir; |
8550eb99 | 416 | unsigned long vaddr, end; |
b239fb25 JF |
417 | |
418 | paravirt_pagetable_setup_start(pgd_base); | |
1da177e4 LT |
419 | |
420 | /* Enable PSE if available */ | |
b239fb25 | 421 | if (cpu_has_pse) |
1da177e4 | 422 | set_in_cr4(X86_CR4_PSE); |
1da177e4 LT |
423 | |
424 | /* Enable PGE if available */ | |
425 | if (cpu_has_pge) { | |
426 | set_in_cr4(X86_CR4_PGE); | |
427 | __PAGE_KERNEL |= _PAGE_GLOBAL; | |
428 | __PAGE_KERNEL_EXEC |= _PAGE_GLOBAL; | |
429 | } | |
430 | ||
431 | kernel_physical_mapping_init(pgd_base); | |
432 | remap_numa_kva(); | |
433 | ||
434 | /* | |
435 | * Fixed mappings, only the page table structure has to be | |
436 | * created - mappings will be set by set_fixmap(): | |
437 | */ | |
beacfaac | 438 | early_ioremap_clear(); |
1da177e4 | 439 | vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; |
b239fb25 JF |
440 | end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK; |
441 | page_table_range_init(vaddr, end, pgd_base); | |
beacfaac | 442 | early_ioremap_reset(); |
1da177e4 LT |
443 | |
444 | permanent_kmaps_init(pgd_base); | |
445 | ||
b239fb25 | 446 | paravirt_pagetable_setup_done(pgd_base); |
1da177e4 LT |
447 | } |
448 | ||
a6eb84bc | 449 | #ifdef CONFIG_ACPI_SLEEP |
1da177e4 | 450 | /* |
a6eb84bc | 451 | * ACPI suspend needs this for resume, because things like the intel-agp |
1da177e4 LT |
452 | * driver might have split up a kernel 4MB mapping. |
453 | */ | |
a6eb84bc | 454 | char swsusp_pg_dir[PAGE_SIZE] |
8550eb99 | 455 | __attribute__ ((aligned(PAGE_SIZE))); |
1da177e4 LT |
456 | |
457 | static inline void save_pg_dir(void) | |
458 | { | |
459 | memcpy(swsusp_pg_dir, swapper_pg_dir, PAGE_SIZE); | |
460 | } | |
a6eb84bc | 461 | #else /* !CONFIG_ACPI_SLEEP */ |
1da177e4 LT |
462 | static inline void save_pg_dir(void) |
463 | { | |
464 | } | |
a6eb84bc | 465 | #endif /* !CONFIG_ACPI_SLEEP */ |
1da177e4 | 466 | |
8550eb99 | 467 | void zap_low_mappings(void) |
1da177e4 LT |
468 | { |
469 | int i; | |
470 | ||
471 | save_pg_dir(); | |
472 | ||
473 | /* | |
474 | * Zap initial low-memory mappings. | |
475 | * | |
476 | * Note that "pgd_clear()" doesn't do it for | |
477 | * us, because pgd_clear() is a no-op on i386. | |
478 | */ | |
68db065c | 479 | for (i = 0; i < KERNEL_PGD_BOUNDARY; i++) { |
1da177e4 LT |
480 | #ifdef CONFIG_X86_PAE |
481 | set_pgd(swapper_pg_dir+i, __pgd(1 + __pa(empty_zero_page))); | |
482 | #else | |
483 | set_pgd(swapper_pg_dir+i, __pgd(0)); | |
484 | #endif | |
8550eb99 | 485 | } |
1da177e4 LT |
486 | flush_tlb_all(); |
487 | } | |
488 | ||
8550eb99 | 489 | int nx_enabled; |
d5321abe | 490 | |
6fdc05d4 JF |
491 | pteval_t __supported_pte_mask __read_mostly = ~_PAGE_NX; |
492 | EXPORT_SYMBOL_GPL(__supported_pte_mask); | |
493 | ||
d5321abe JB |
494 | #ifdef CONFIG_X86_PAE |
495 | ||
8550eb99 | 496 | static int disable_nx __initdata; |
1da177e4 LT |
497 | |
498 | /* | |
499 | * noexec = on|off | |
500 | * | |
501 | * Control non executable mappings. | |
502 | * | |
503 | * on Enable | |
504 | * off Disable | |
505 | */ | |
1a3f239d | 506 | static int __init noexec_setup(char *str) |
1da177e4 | 507 | { |
1a3f239d RR |
508 | if (!str || !strcmp(str, "on")) { |
509 | if (cpu_has_nx) { | |
510 | __supported_pte_mask |= _PAGE_NX; | |
511 | disable_nx = 0; | |
512 | } | |
8550eb99 IM |
513 | } else { |
514 | if (!strcmp(str, "off")) { | |
515 | disable_nx = 1; | |
516 | __supported_pte_mask &= ~_PAGE_NX; | |
517 | } else { | |
518 | return -EINVAL; | |
519 | } | |
520 | } | |
1a3f239d RR |
521 | |
522 | return 0; | |
1da177e4 | 523 | } |
1a3f239d | 524 | early_param("noexec", noexec_setup); |
1da177e4 | 525 | |
1da177e4 LT |
526 | static void __init set_nx(void) |
527 | { | |
528 | unsigned int v[4], l, h; | |
529 | ||
530 | if (cpu_has_pae && (cpuid_eax(0x80000000) > 0x80000001)) { | |
531 | cpuid(0x80000001, &v[0], &v[1], &v[2], &v[3]); | |
8550eb99 | 532 | |
1da177e4 LT |
533 | if ((v[3] & (1 << 20)) && !disable_nx) { |
534 | rdmsr(MSR_EFER, l, h); | |
535 | l |= EFER_NX; | |
536 | wrmsr(MSR_EFER, l, h); | |
537 | nx_enabled = 1; | |
538 | __supported_pte_mask |= _PAGE_NX; | |
539 | } | |
540 | } | |
541 | } | |
1da177e4 LT |
542 | #endif |
543 | ||
544 | /* | |
545 | * paging_init() sets up the page tables - note that the first 8MB are | |
546 | * already mapped by head.S. | |
547 | * | |
548 | * This routines also unmaps the page at virtual kernel address 0, so | |
549 | * that we can trap those pesky NULL-reference errors in the kernel. | |
550 | */ | |
551 | void __init paging_init(void) | |
552 | { | |
553 | #ifdef CONFIG_X86_PAE | |
554 | set_nx(); | |
555 | if (nx_enabled) | |
d7d119d7 | 556 | printk(KERN_INFO "NX (Execute Disable) protection: active\n"); |
1da177e4 | 557 | #endif |
1da177e4 LT |
558 | pagetable_init(); |
559 | ||
560 | load_cr3(swapper_pg_dir); | |
561 | ||
1da177e4 LT |
562 | __flush_tlb_all(); |
563 | ||
564 | kmap_init(); | |
565 | } | |
566 | ||
567 | /* | |
568 | * Test if the WP bit works in supervisor mode. It isn't supported on 386's | |
569 | * and also on some strange 486's (NexGen etc.). All 586+'s are OK. This | |
570 | * used to involve black magic jumps to work around some nasty CPU bugs, | |
571 | * but fortunately the switch to using exceptions got rid of all that. | |
572 | */ | |
1da177e4 LT |
573 | static void __init test_wp_bit(void) |
574 | { | |
d7d119d7 IM |
575 | printk(KERN_INFO |
576 | "Checking if this processor honours the WP bit even in supervisor mode..."); | |
1da177e4 LT |
577 | |
578 | /* Any page-aligned address will do, the test is non-destructive */ | |
579 | __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_READONLY); | |
580 | boot_cpu_data.wp_works_ok = do_test_wp_bit(); | |
581 | clear_fixmap(FIX_WP_TEST); | |
582 | ||
583 | if (!boot_cpu_data.wp_works_ok) { | |
d7d119d7 | 584 | printk(KERN_CONT "No.\n"); |
1da177e4 | 585 | #ifdef CONFIG_X86_WP_WORKS_OK |
d7d119d7 IM |
586 | panic( |
587 | "This kernel doesn't support CPU's with broken WP. Recompile it for a 386!"); | |
1da177e4 LT |
588 | #endif |
589 | } else { | |
d7d119d7 | 590 | printk(KERN_CONT "Ok.\n"); |
1da177e4 LT |
591 | } |
592 | } | |
593 | ||
8550eb99 | 594 | static struct kcore_list kcore_mem, kcore_vmalloc; |
1da177e4 LT |
595 | |
596 | void __init mem_init(void) | |
597 | { | |
1da177e4 | 598 | int codesize, reservedpages, datasize, initsize; |
8550eb99 | 599 | int tmp, bad_ppro; |
1da177e4 | 600 | |
05b79bdc | 601 | #ifdef CONFIG_FLATMEM |
8d8f3cbe | 602 | BUG_ON(!mem_map); |
1da177e4 | 603 | #endif |
1da177e4 LT |
604 | bad_ppro = ppro_with_ram_bug(); |
605 | ||
606 | #ifdef CONFIG_HIGHMEM | |
607 | /* check that fixmap and pkmap do not overlap */ | |
d7d119d7 IM |
608 | if (PKMAP_BASE + LAST_PKMAP*PAGE_SIZE >= FIXADDR_START) { |
609 | printk(KERN_ERR | |
610 | "fixmap and kmap areas overlap - this will crash\n"); | |
1da177e4 | 611 | printk(KERN_ERR "pkstart: %lxh pkend: %lxh fixstart %lxh\n", |
d7d119d7 IM |
612 | PKMAP_BASE, PKMAP_BASE + LAST_PKMAP*PAGE_SIZE, |
613 | FIXADDR_START); | |
1da177e4 LT |
614 | BUG(); |
615 | } | |
616 | #endif | |
1da177e4 LT |
617 | /* this will put all low memory onto the freelists */ |
618 | totalram_pages += free_all_bootmem(); | |
619 | ||
620 | reservedpages = 0; | |
621 | for (tmp = 0; tmp < max_low_pfn; tmp++) | |
622 | /* | |
8550eb99 | 623 | * Only count reserved RAM pages: |
1da177e4 LT |
624 | */ |
625 | if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp))) | |
626 | reservedpages++; | |
627 | ||
628 | set_highmem_pages_init(bad_ppro); | |
629 | ||
630 | codesize = (unsigned long) &_etext - (unsigned long) &_text; | |
631 | datasize = (unsigned long) &_edata - (unsigned long) &_etext; | |
632 | initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; | |
633 | ||
8550eb99 IM |
634 | kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT); |
635 | kclist_add(&kcore_vmalloc, (void *)VMALLOC_START, | |
1da177e4 LT |
636 | VMALLOC_END-VMALLOC_START); |
637 | ||
8550eb99 IM |
638 | printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, " |
639 | "%dk reserved, %dk data, %dk init, %ldk highmem)\n", | |
1da177e4 LT |
640 | (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), |
641 | num_physpages << (PAGE_SHIFT-10), | |
642 | codesize >> 10, | |
643 | reservedpages << (PAGE_SHIFT-10), | |
644 | datasize >> 10, | |
645 | initsize >> 10, | |
646 | (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)) | |
647 | ); | |
648 | ||
052e7994 | 649 | #if 1 /* double-sanity-check paranoia */ |
d7d119d7 | 650 | printk(KERN_INFO "virtual kernel memory layout:\n" |
8550eb99 | 651 | " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n" |
052e7994 | 652 | #ifdef CONFIG_HIGHMEM |
8550eb99 | 653 | " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n" |
052e7994 | 654 | #endif |
8550eb99 IM |
655 | " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n" |
656 | " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n" | |
657 | " .init : 0x%08lx - 0x%08lx (%4ld kB)\n" | |
658 | " .data : 0x%08lx - 0x%08lx (%4ld kB)\n" | |
659 | " .text : 0x%08lx - 0x%08lx (%4ld kB)\n", | |
660 | FIXADDR_START, FIXADDR_TOP, | |
661 | (FIXADDR_TOP - FIXADDR_START) >> 10, | |
052e7994 JF |
662 | |
663 | #ifdef CONFIG_HIGHMEM | |
8550eb99 IM |
664 | PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE, |
665 | (LAST_PKMAP*PAGE_SIZE) >> 10, | |
052e7994 JF |
666 | #endif |
667 | ||
8550eb99 IM |
668 | VMALLOC_START, VMALLOC_END, |
669 | (VMALLOC_END - VMALLOC_START) >> 20, | |
052e7994 | 670 | |
8550eb99 IM |
671 | (unsigned long)__va(0), (unsigned long)high_memory, |
672 | ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20, | |
052e7994 | 673 | |
8550eb99 IM |
674 | (unsigned long)&__init_begin, (unsigned long)&__init_end, |
675 | ((unsigned long)&__init_end - | |
676 | (unsigned long)&__init_begin) >> 10, | |
052e7994 | 677 | |
8550eb99 IM |
678 | (unsigned long)&_etext, (unsigned long)&_edata, |
679 | ((unsigned long)&_edata - (unsigned long)&_etext) >> 10, | |
052e7994 | 680 | |
8550eb99 IM |
681 | (unsigned long)&_text, (unsigned long)&_etext, |
682 | ((unsigned long)&_etext - (unsigned long)&_text) >> 10); | |
052e7994 JF |
683 | |
684 | #ifdef CONFIG_HIGHMEM | |
8550eb99 IM |
685 | BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START); |
686 | BUG_ON(VMALLOC_END > PKMAP_BASE); | |
052e7994 | 687 | #endif |
8550eb99 IM |
688 | BUG_ON(VMALLOC_START > VMALLOC_END); |
689 | BUG_ON((unsigned long)high_memory > VMALLOC_START); | |
052e7994 JF |
690 | #endif /* double-sanity-check paranoia */ |
691 | ||
1da177e4 LT |
692 | if (boot_cpu_data.wp_works_ok < 0) |
693 | test_wp_bit(); | |
694 | ||
76ebd054 TG |
695 | cpa_init(); |
696 | ||
1da177e4 LT |
697 | /* |
698 | * Subtle. SMP is doing it's boot stuff late (because it has to | |
699 | * fork idle threads) - but it also needs low mappings for the | |
700 | * protected-mode entry to work. We zap these entries only after | |
701 | * the WP-bit has been tested. | |
702 | */ | |
703 | #ifndef CONFIG_SMP | |
704 | zap_low_mappings(); | |
705 | #endif | |
706 | } | |
707 | ||
ad8f5797 | 708 | #ifdef CONFIG_MEMORY_HOTPLUG |
bc02af93 | 709 | int arch_add_memory(int nid, u64 start, u64 size) |
05039b92 | 710 | { |
7c7e9425 | 711 | struct pglist_data *pgdata = NODE_DATA(nid); |
776ed98b | 712 | struct zone *zone = pgdata->node_zones + ZONE_HIGHMEM; |
05039b92 DH |
713 | unsigned long start_pfn = start >> PAGE_SHIFT; |
714 | unsigned long nr_pages = size >> PAGE_SHIFT; | |
715 | ||
716 | return __add_pages(zone, start_pfn, nr_pages); | |
717 | } | |
9d99aaa3 | 718 | #endif |
05039b92 | 719 | |
1da177e4 LT |
720 | /* |
721 | * This function cannot be __init, since exceptions don't work in that | |
722 | * section. Put this after the callers, so that it cannot be inlined. | |
723 | */ | |
8550eb99 | 724 | static noinline int do_test_wp_bit(void) |
1da177e4 LT |
725 | { |
726 | char tmp_reg; | |
727 | int flag; | |
728 | ||
729 | __asm__ __volatile__( | |
8550eb99 IM |
730 | " movb %0, %1 \n" |
731 | "1: movb %1, %0 \n" | |
732 | " xorl %2, %2 \n" | |
1da177e4 | 733 | "2: \n" |
f832ff18 | 734 | _ASM_EXTABLE(1b,2b) |
1da177e4 LT |
735 | :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)), |
736 | "=q" (tmp_reg), | |
737 | "=r" (flag) | |
738 | :"2" (1) | |
739 | :"memory"); | |
8550eb99 | 740 | |
1da177e4 LT |
741 | return flag; |
742 | } | |
743 | ||
63aaf308 | 744 | #ifdef CONFIG_DEBUG_RODATA |
edeed305 AV |
745 | const int rodata_test_data = 0xC3; |
746 | EXPORT_SYMBOL_GPL(rodata_test_data); | |
63aaf308 | 747 | |
63aaf308 AV |
748 | void mark_rodata_ro(void) |
749 | { | |
6fb14755 JB |
750 | unsigned long start = PFN_ALIGN(_text); |
751 | unsigned long size = PFN_ALIGN(_etext) - start; | |
63aaf308 | 752 | |
4e4eee0e MD |
753 | set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); |
754 | printk(KERN_INFO "Write protecting the kernel text: %luk\n", | |
755 | size >> 10); | |
0c42f392 AK |
756 | |
757 | #ifdef CONFIG_CPA_DEBUG | |
4e4eee0e MD |
758 | printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n", |
759 | start, start+size); | |
760 | set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT); | |
0c42f392 | 761 | |
4e4eee0e MD |
762 | printk(KERN_INFO "Testing CPA: write protecting again\n"); |
763 | set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT); | |
602033ed | 764 | #endif |
6fb14755 JB |
765 | start += size; |
766 | size = (unsigned long)__end_rodata - start; | |
6d238cc4 | 767 | set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); |
d7d119d7 IM |
768 | printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", |
769 | size >> 10); | |
edeed305 | 770 | rodata_test(); |
63aaf308 | 771 | |
0c42f392 | 772 | #ifdef CONFIG_CPA_DEBUG |
d7d119d7 | 773 | printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size); |
6d238cc4 | 774 | set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT); |
0c42f392 | 775 | |
d7d119d7 | 776 | printk(KERN_INFO "Testing CPA: write protecting again\n"); |
6d238cc4 | 777 | set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); |
0c42f392 | 778 | #endif |
63aaf308 AV |
779 | } |
780 | #endif | |
781 | ||
9a0b5817 GH |
782 | void free_init_pages(char *what, unsigned long begin, unsigned long end) |
783 | { | |
ee01f112 IM |
784 | #ifdef CONFIG_DEBUG_PAGEALLOC |
785 | /* | |
786 | * If debugging page accesses then do not free this memory but | |
787 | * mark them not present - any buggy init-section access will | |
788 | * create a kernel page fault: | |
789 | */ | |
790 | printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n", | |
791 | begin, PAGE_ALIGN(end)); | |
792 | set_memory_np(begin, (end - begin) >> PAGE_SHIFT); | |
793 | #else | |
86f03989 IM |
794 | unsigned long addr; |
795 | ||
3c1df68b AV |
796 | /* |
797 | * We just marked the kernel text read only above, now that | |
798 | * we are going to free part of that, we need to make that | |
799 | * writeable first. | |
800 | */ | |
801 | set_memory_rw(begin, (end - begin) >> PAGE_SHIFT); | |
802 | ||
9a0b5817 | 803 | for (addr = begin; addr < end; addr += PAGE_SIZE) { |
e3ebadd9 LT |
804 | ClearPageReserved(virt_to_page(addr)); |
805 | init_page_count(virt_to_page(addr)); | |
806 | memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE); | |
807 | free_page(addr); | |
9a0b5817 GH |
808 | totalram_pages++; |
809 | } | |
6fb14755 | 810 | printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10); |
ee01f112 | 811 | #endif |
9a0b5817 GH |
812 | } |
813 | ||
814 | void free_initmem(void) | |
815 | { | |
816 | free_init_pages("unused kernel memory", | |
e3ebadd9 LT |
817 | (unsigned long)(&__init_begin), |
818 | (unsigned long)(&__init_end)); | |
9a0b5817 | 819 | } |
63aaf308 | 820 | |
1da177e4 LT |
821 | #ifdef CONFIG_BLK_DEV_INITRD |
822 | void free_initrd_mem(unsigned long start, unsigned long end) | |
823 | { | |
e3ebadd9 | 824 | free_init_pages("initrd memory", start, end); |
1da177e4 LT |
825 | } |
826 | #endif |