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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/arch/i386/mm/pgtable.c | |
3 | */ | |
4 | ||
1da177e4 LT |
5 | #include <linux/sched.h> |
6 | #include <linux/kernel.h> | |
7 | #include <linux/errno.h> | |
8 | #include <linux/mm.h> | |
9 | #include <linux/swap.h> | |
10 | #include <linux/smp.h> | |
11 | #include <linux/highmem.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/pagemap.h> | |
14 | #include <linux/spinlock.h> | |
052e7994 | 15 | #include <linux/module.h> |
1da177e4 LT |
16 | |
17 | #include <asm/system.h> | |
18 | #include <asm/pgtable.h> | |
19 | #include <asm/pgalloc.h> | |
20 | #include <asm/fixmap.h> | |
21 | #include <asm/e820.h> | |
22 | #include <asm/tlb.h> | |
23 | #include <asm/tlbflush.h> | |
24 | ||
25 | void show_mem(void) | |
26 | { | |
27 | int total = 0, reserved = 0; | |
28 | int shared = 0, cached = 0; | |
29 | int highmem = 0; | |
30 | struct page *page; | |
31 | pg_data_t *pgdat; | |
32 | unsigned long i; | |
208d54e5 | 33 | unsigned long flags; |
1da177e4 | 34 | |
f90e7185 | 35 | printk(KERN_INFO "Mem-info:\n"); |
1da177e4 | 36 | show_free_areas(); |
f90e7185 | 37 | printk(KERN_INFO "Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10)); |
ec936fc5 | 38 | for_each_online_pgdat(pgdat) { |
208d54e5 | 39 | pgdat_resize_lock(pgdat, &flags); |
1da177e4 | 40 | for (i = 0; i < pgdat->node_spanned_pages; ++i) { |
408fde81 | 41 | page = pgdat_page_nr(pgdat, i); |
1da177e4 LT |
42 | total++; |
43 | if (PageHighMem(page)) | |
44 | highmem++; | |
45 | if (PageReserved(page)) | |
46 | reserved++; | |
47 | else if (PageSwapCache(page)) | |
48 | cached++; | |
49 | else if (page_count(page)) | |
50 | shared += page_count(page) - 1; | |
51 | } | |
208d54e5 | 52 | pgdat_resize_unlock(pgdat, &flags); |
1da177e4 | 53 | } |
f90e7185 CL |
54 | printk(KERN_INFO "%d pages of RAM\n", total); |
55 | printk(KERN_INFO "%d pages of HIGHMEM\n", highmem); | |
56 | printk(KERN_INFO "%d reserved pages\n", reserved); | |
57 | printk(KERN_INFO "%d pages shared\n", shared); | |
58 | printk(KERN_INFO "%d pages swap cached\n", cached); | |
6f4e1e50 | 59 | |
b1e7a8fd | 60 | printk(KERN_INFO "%lu pages dirty\n", global_page_state(NR_FILE_DIRTY)); |
ce866b34 CL |
61 | printk(KERN_INFO "%lu pages writeback\n", |
62 | global_page_state(NR_WRITEBACK)); | |
65ba55f5 | 63 | printk(KERN_INFO "%lu pages mapped\n", global_page_state(NR_FILE_MAPPED)); |
972d1a7b CL |
64 | printk(KERN_INFO "%lu pages slab\n", |
65 | global_page_state(NR_SLAB_RECLAIMABLE) + | |
66 | global_page_state(NR_SLAB_UNRECLAIMABLE)); | |
df849a15 CL |
67 | printk(KERN_INFO "%lu pages pagetables\n", |
68 | global_page_state(NR_PAGETABLE)); | |
1da177e4 LT |
69 | } |
70 | ||
71 | /* | |
72 | * Associate a virtual page frame with a given physical page frame | |
73 | * and protection flags for that frame. | |
74 | */ | |
75 | static void set_pte_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags) | |
76 | { | |
77 | pgd_t *pgd; | |
78 | pud_t *pud; | |
79 | pmd_t *pmd; | |
80 | pte_t *pte; | |
81 | ||
82 | pgd = swapper_pg_dir + pgd_index(vaddr); | |
83 | if (pgd_none(*pgd)) { | |
84 | BUG(); | |
85 | return; | |
86 | } | |
87 | pud = pud_offset(pgd, vaddr); | |
88 | if (pud_none(*pud)) { | |
89 | BUG(); | |
90 | return; | |
91 | } | |
92 | pmd = pmd_offset(pud, vaddr); | |
93 | if (pmd_none(*pmd)) { | |
94 | BUG(); | |
95 | return; | |
96 | } | |
97 | pte = pte_offset_kernel(pmd, vaddr); | |
98 | /* <pfn,flags> stored as-is, to permit clearing entries */ | |
99 | set_pte(pte, pfn_pte(pfn, flags)); | |
100 | ||
101 | /* | |
102 | * It's enough to flush this one mapping. | |
103 | * (PGE mappings get flushed as well) | |
104 | */ | |
105 | __flush_tlb_one(vaddr); | |
106 | } | |
107 | ||
108 | /* | |
109 | * Associate a large virtual page frame with a given physical page frame | |
110 | * and protection flags for that frame. pfn is for the base of the page, | |
111 | * vaddr is what the page gets mapped to - both must be properly aligned. | |
112 | * The pmd must already be instantiated. Assumes PAE mode. | |
113 | */ | |
114 | void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags) | |
115 | { | |
116 | pgd_t *pgd; | |
117 | pud_t *pud; | |
118 | pmd_t *pmd; | |
119 | ||
120 | if (vaddr & (PMD_SIZE-1)) { /* vaddr is misaligned */ | |
f90e7185 | 121 | printk(KERN_WARNING "set_pmd_pfn: vaddr misaligned\n"); |
1da177e4 LT |
122 | return; /* BUG(); */ |
123 | } | |
124 | if (pfn & (PTRS_PER_PTE-1)) { /* pfn is misaligned */ | |
f90e7185 | 125 | printk(KERN_WARNING "set_pmd_pfn: pfn misaligned\n"); |
1da177e4 LT |
126 | return; /* BUG(); */ |
127 | } | |
128 | pgd = swapper_pg_dir + pgd_index(vaddr); | |
129 | if (pgd_none(*pgd)) { | |
f90e7185 | 130 | printk(KERN_WARNING "set_pmd_pfn: pgd_none\n"); |
1da177e4 LT |
131 | return; /* BUG(); */ |
132 | } | |
133 | pud = pud_offset(pgd, vaddr); | |
134 | pmd = pmd_offset(pud, vaddr); | |
135 | set_pmd(pmd, pfn_pmd(pfn, flags)); | |
136 | /* | |
137 | * It's enough to flush this one mapping. | |
138 | * (PGE mappings get flushed as well) | |
139 | */ | |
140 | __flush_tlb_one(vaddr); | |
141 | } | |
142 | ||
052e7994 JF |
143 | static int fixmaps; |
144 | #ifndef CONFIG_COMPAT_VDSO | |
145 | unsigned long __FIXADDR_TOP = 0xfffff000; | |
146 | EXPORT_SYMBOL(__FIXADDR_TOP); | |
147 | #endif | |
148 | ||
1da177e4 LT |
149 | void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags) |
150 | { | |
151 | unsigned long address = __fix_to_virt(idx); | |
152 | ||
153 | if (idx >= __end_of_fixed_addresses) { | |
154 | BUG(); | |
155 | return; | |
156 | } | |
157 | set_pte_pfn(address, phys >> PAGE_SHIFT, flags); | |
052e7994 JF |
158 | fixmaps++; |
159 | } | |
160 | ||
161 | /** | |
162 | * reserve_top_address - reserves a hole in the top of kernel address space | |
163 | * @reserve - size of hole to reserve | |
164 | * | |
165 | * Can be used to relocate the fixmap area and poke a hole in the top | |
166 | * of kernel address space to make room for a hypervisor. | |
167 | */ | |
168 | void reserve_top_address(unsigned long reserve) | |
169 | { | |
170 | BUG_ON(fixmaps > 0); | |
171 | #ifdef CONFIG_COMPAT_VDSO | |
172 | BUG_ON(reserve != 0); | |
173 | #else | |
174 | __FIXADDR_TOP = -reserve - PAGE_SIZE; | |
175 | __VMALLOC_RESERVE += reserve; | |
176 | #endif | |
1da177e4 LT |
177 | } |
178 | ||
179 | pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) | |
180 | { | |
181 | return (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); | |
182 | } | |
183 | ||
184 | struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address) | |
185 | { | |
186 | struct page *pte; | |
187 | ||
188 | #ifdef CONFIG_HIGHPTE | |
189 | pte = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT|__GFP_ZERO, 0); | |
190 | #else | |
191 | pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0); | |
192 | #endif | |
193 | return pte; | |
194 | } | |
195 | ||
196 | void pmd_ctor(void *pmd, kmem_cache_t *cache, unsigned long flags) | |
197 | { | |
198 | memset(pmd, 0, PTRS_PER_PMD*sizeof(pmd_t)); | |
199 | } | |
200 | ||
201 | /* | |
202 | * List of all pgd's needed for non-PAE so it can invalidate entries | |
203 | * in both cached and uncached pgd's; not needed for PAE since the | |
204 | * kernel pmd is shared. If PAE were not to share the pmd a similar | |
205 | * tactic would be needed. This is essentially codepath-based locking | |
206 | * against pageattr.c; it is the unique case in which a valid change | |
207 | * of kernel pagetables can't be lazily synchronized by vmalloc faults. | |
208 | * vmalloc faults work because attached pagetables are never freed. | |
209 | * The locking scheme was chosen on the basis of manfred's | |
210 | * recommendations and having no core impact whatsoever. | |
211 | * -- wli | |
212 | */ | |
213 | DEFINE_SPINLOCK(pgd_lock); | |
214 | struct page *pgd_list; | |
215 | ||
216 | static inline void pgd_list_add(pgd_t *pgd) | |
217 | { | |
218 | struct page *page = virt_to_page(pgd); | |
219 | page->index = (unsigned long)pgd_list; | |
220 | if (pgd_list) | |
4c21e2f2 | 221 | set_page_private(pgd_list, (unsigned long)&page->index); |
1da177e4 | 222 | pgd_list = page; |
4c21e2f2 | 223 | set_page_private(page, (unsigned long)&pgd_list); |
1da177e4 LT |
224 | } |
225 | ||
226 | static inline void pgd_list_del(pgd_t *pgd) | |
227 | { | |
228 | struct page *next, **pprev, *page = virt_to_page(pgd); | |
229 | next = (struct page *)page->index; | |
4c21e2f2 | 230 | pprev = (struct page **)page_private(page); |
1da177e4 LT |
231 | *pprev = next; |
232 | if (next) | |
4c21e2f2 | 233 | set_page_private(next, (unsigned long)pprev); |
1da177e4 LT |
234 | } |
235 | ||
236 | void pgd_ctor(void *pgd, kmem_cache_t *cache, unsigned long unused) | |
237 | { | |
238 | unsigned long flags; | |
239 | ||
d7271b14 ZA |
240 | if (PTRS_PER_PMD == 1) { |
241 | memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t)); | |
1da177e4 | 242 | spin_lock_irqsave(&pgd_lock, flags); |
d7271b14 | 243 | } |
1da177e4 | 244 | |
d7271b14 | 245 | clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD, |
1da177e4 | 246 | swapper_pg_dir + USER_PTRS_PER_PGD, |
d7271b14 | 247 | KERNEL_PGD_PTRS); |
1da177e4 LT |
248 | if (PTRS_PER_PMD > 1) |
249 | return; | |
250 | ||
251 | pgd_list_add(pgd); | |
252 | spin_unlock_irqrestore(&pgd_lock, flags); | |
1da177e4 LT |
253 | } |
254 | ||
255 | /* never called when PTRS_PER_PMD > 1 */ | |
256 | void pgd_dtor(void *pgd, kmem_cache_t *cache, unsigned long unused) | |
257 | { | |
258 | unsigned long flags; /* can be called from interrupt context */ | |
259 | ||
260 | spin_lock_irqsave(&pgd_lock, flags); | |
261 | pgd_list_del(pgd); | |
262 | spin_unlock_irqrestore(&pgd_lock, flags); | |
263 | } | |
264 | ||
265 | pgd_t *pgd_alloc(struct mm_struct *mm) | |
266 | { | |
267 | int i; | |
268 | pgd_t *pgd = kmem_cache_alloc(pgd_cache, GFP_KERNEL); | |
269 | ||
270 | if (PTRS_PER_PMD == 1 || !pgd) | |
271 | return pgd; | |
272 | ||
273 | for (i = 0; i < USER_PTRS_PER_PGD; ++i) { | |
274 | pmd_t *pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL); | |
275 | if (!pmd) | |
276 | goto out_oom; | |
277 | set_pgd(&pgd[i], __pgd(1 + __pa(pmd))); | |
278 | } | |
279 | return pgd; | |
280 | ||
281 | out_oom: | |
282 | for (i--; i >= 0; i--) | |
283 | kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1)); | |
284 | kmem_cache_free(pgd_cache, pgd); | |
285 | return NULL; | |
286 | } | |
287 | ||
288 | void pgd_free(pgd_t *pgd) | |
289 | { | |
290 | int i; | |
291 | ||
292 | /* in the PAE case user pgd entries are overwritten before usage */ | |
293 | if (PTRS_PER_PMD > 1) | |
294 | for (i = 0; i < USER_PTRS_PER_PGD; ++i) | |
295 | kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1)); | |
e0da382c | 296 | /* in the non-PAE case, free_pgtables() clears user pgd entries */ |
1da177e4 LT |
297 | kmem_cache_free(pgd_cache, pgd); |
298 | } |