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1da177e4 LT |
1 | /* |
2 | * linux/arch/i386/mm/pgtable.c | |
3 | */ | |
4 | ||
5 | #include <linux/config.h> | |
6 | #include <linux/sched.h> | |
7 | #include <linux/kernel.h> | |
8 | #include <linux/errno.h> | |
9 | #include <linux/mm.h> | |
10 | #include <linux/swap.h> | |
11 | #include <linux/smp.h> | |
12 | #include <linux/highmem.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/pagemap.h> | |
15 | #include <linux/spinlock.h> | |
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; | |
33 | ||
34 | printk("Mem-info:\n"); | |
35 | show_free_areas(); | |
36 | printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10)); | |
37 | for_each_pgdat(pgdat) { | |
38 | for (i = 0; i < pgdat->node_spanned_pages; ++i) { | |
39 | page = pgdat->node_mem_map + i; | |
40 | total++; | |
41 | if (PageHighMem(page)) | |
42 | highmem++; | |
43 | if (PageReserved(page)) | |
44 | reserved++; | |
45 | else if (PageSwapCache(page)) | |
46 | cached++; | |
47 | else if (page_count(page)) | |
48 | shared += page_count(page) - 1; | |
49 | } | |
50 | } | |
51 | printk("%d pages of RAM\n", total); | |
52 | printk("%d pages of HIGHMEM\n",highmem); | |
53 | printk("%d reserved pages\n",reserved); | |
54 | printk("%d pages shared\n",shared); | |
55 | printk("%d pages swap cached\n",cached); | |
56 | } | |
57 | ||
58 | /* | |
59 | * Associate a virtual page frame with a given physical page frame | |
60 | * and protection flags for that frame. | |
61 | */ | |
62 | static void set_pte_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags) | |
63 | { | |
64 | pgd_t *pgd; | |
65 | pud_t *pud; | |
66 | pmd_t *pmd; | |
67 | pte_t *pte; | |
68 | ||
69 | pgd = swapper_pg_dir + pgd_index(vaddr); | |
70 | if (pgd_none(*pgd)) { | |
71 | BUG(); | |
72 | return; | |
73 | } | |
74 | pud = pud_offset(pgd, vaddr); | |
75 | if (pud_none(*pud)) { | |
76 | BUG(); | |
77 | return; | |
78 | } | |
79 | pmd = pmd_offset(pud, vaddr); | |
80 | if (pmd_none(*pmd)) { | |
81 | BUG(); | |
82 | return; | |
83 | } | |
84 | pte = pte_offset_kernel(pmd, vaddr); | |
85 | /* <pfn,flags> stored as-is, to permit clearing entries */ | |
86 | set_pte(pte, pfn_pte(pfn, flags)); | |
87 | ||
88 | /* | |
89 | * It's enough to flush this one mapping. | |
90 | * (PGE mappings get flushed as well) | |
91 | */ | |
92 | __flush_tlb_one(vaddr); | |
93 | } | |
94 | ||
95 | /* | |
96 | * Associate a large virtual page frame with a given physical page frame | |
97 | * and protection flags for that frame. pfn is for the base of the page, | |
98 | * vaddr is what the page gets mapped to - both must be properly aligned. | |
99 | * The pmd must already be instantiated. Assumes PAE mode. | |
100 | */ | |
101 | void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags) | |
102 | { | |
103 | pgd_t *pgd; | |
104 | pud_t *pud; | |
105 | pmd_t *pmd; | |
106 | ||
107 | if (vaddr & (PMD_SIZE-1)) { /* vaddr is misaligned */ | |
108 | printk ("set_pmd_pfn: vaddr misaligned\n"); | |
109 | return; /* BUG(); */ | |
110 | } | |
111 | if (pfn & (PTRS_PER_PTE-1)) { /* pfn is misaligned */ | |
112 | printk ("set_pmd_pfn: pfn misaligned\n"); | |
113 | return; /* BUG(); */ | |
114 | } | |
115 | pgd = swapper_pg_dir + pgd_index(vaddr); | |
116 | if (pgd_none(*pgd)) { | |
117 | printk ("set_pmd_pfn: pgd_none\n"); | |
118 | return; /* BUG(); */ | |
119 | } | |
120 | pud = pud_offset(pgd, vaddr); | |
121 | pmd = pmd_offset(pud, vaddr); | |
122 | set_pmd(pmd, pfn_pmd(pfn, flags)); | |
123 | /* | |
124 | * It's enough to flush this one mapping. | |
125 | * (PGE mappings get flushed as well) | |
126 | */ | |
127 | __flush_tlb_one(vaddr); | |
128 | } | |
129 | ||
130 | void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags) | |
131 | { | |
132 | unsigned long address = __fix_to_virt(idx); | |
133 | ||
134 | if (idx >= __end_of_fixed_addresses) { | |
135 | BUG(); | |
136 | return; | |
137 | } | |
138 | set_pte_pfn(address, phys >> PAGE_SHIFT, flags); | |
139 | } | |
140 | ||
141 | pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) | |
142 | { | |
143 | return (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); | |
144 | } | |
145 | ||
146 | struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address) | |
147 | { | |
148 | struct page *pte; | |
149 | ||
150 | #ifdef CONFIG_HIGHPTE | |
151 | pte = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT|__GFP_ZERO, 0); | |
152 | #else | |
153 | pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0); | |
154 | #endif | |
155 | return pte; | |
156 | } | |
157 | ||
158 | void pmd_ctor(void *pmd, kmem_cache_t *cache, unsigned long flags) | |
159 | { | |
160 | memset(pmd, 0, PTRS_PER_PMD*sizeof(pmd_t)); | |
161 | } | |
162 | ||
163 | /* | |
164 | * List of all pgd's needed for non-PAE so it can invalidate entries | |
165 | * in both cached and uncached pgd's; not needed for PAE since the | |
166 | * kernel pmd is shared. If PAE were not to share the pmd a similar | |
167 | * tactic would be needed. This is essentially codepath-based locking | |
168 | * against pageattr.c; it is the unique case in which a valid change | |
169 | * of kernel pagetables can't be lazily synchronized by vmalloc faults. | |
170 | * vmalloc faults work because attached pagetables are never freed. | |
171 | * The locking scheme was chosen on the basis of manfred's | |
172 | * recommendations and having no core impact whatsoever. | |
173 | * -- wli | |
174 | */ | |
175 | DEFINE_SPINLOCK(pgd_lock); | |
176 | struct page *pgd_list; | |
177 | ||
178 | static inline void pgd_list_add(pgd_t *pgd) | |
179 | { | |
180 | struct page *page = virt_to_page(pgd); | |
181 | page->index = (unsigned long)pgd_list; | |
182 | if (pgd_list) | |
183 | pgd_list->private = (unsigned long)&page->index; | |
184 | pgd_list = page; | |
185 | page->private = (unsigned long)&pgd_list; | |
186 | } | |
187 | ||
188 | static inline void pgd_list_del(pgd_t *pgd) | |
189 | { | |
190 | struct page *next, **pprev, *page = virt_to_page(pgd); | |
191 | next = (struct page *)page->index; | |
192 | pprev = (struct page **)page->private; | |
193 | *pprev = next; | |
194 | if (next) | |
195 | next->private = (unsigned long)pprev; | |
196 | } | |
197 | ||
198 | void pgd_ctor(void *pgd, kmem_cache_t *cache, unsigned long unused) | |
199 | { | |
200 | unsigned long flags; | |
201 | ||
202 | if (PTRS_PER_PMD == 1) | |
203 | spin_lock_irqsave(&pgd_lock, flags); | |
204 | ||
205 | memcpy((pgd_t *)pgd + USER_PTRS_PER_PGD, | |
206 | swapper_pg_dir + USER_PTRS_PER_PGD, | |
207 | (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t)); | |
208 | ||
209 | if (PTRS_PER_PMD > 1) | |
210 | return; | |
211 | ||
212 | pgd_list_add(pgd); | |
213 | spin_unlock_irqrestore(&pgd_lock, flags); | |
214 | memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t)); | |
215 | } | |
216 | ||
217 | /* never called when PTRS_PER_PMD > 1 */ | |
218 | void pgd_dtor(void *pgd, kmem_cache_t *cache, unsigned long unused) | |
219 | { | |
220 | unsigned long flags; /* can be called from interrupt context */ | |
221 | ||
222 | spin_lock_irqsave(&pgd_lock, flags); | |
223 | pgd_list_del(pgd); | |
224 | spin_unlock_irqrestore(&pgd_lock, flags); | |
225 | } | |
226 | ||
227 | pgd_t *pgd_alloc(struct mm_struct *mm) | |
228 | { | |
229 | int i; | |
230 | pgd_t *pgd = kmem_cache_alloc(pgd_cache, GFP_KERNEL); | |
231 | ||
232 | if (PTRS_PER_PMD == 1 || !pgd) | |
233 | return pgd; | |
234 | ||
235 | for (i = 0; i < USER_PTRS_PER_PGD; ++i) { | |
236 | pmd_t *pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL); | |
237 | if (!pmd) | |
238 | goto out_oom; | |
239 | set_pgd(&pgd[i], __pgd(1 + __pa(pmd))); | |
240 | } | |
241 | return pgd; | |
242 | ||
243 | out_oom: | |
244 | for (i--; i >= 0; i--) | |
245 | kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1)); | |
246 | kmem_cache_free(pgd_cache, pgd); | |
247 | return NULL; | |
248 | } | |
249 | ||
250 | void pgd_free(pgd_t *pgd) | |
251 | { | |
252 | int i; | |
253 | ||
254 | /* in the PAE case user pgd entries are overwritten before usage */ | |
255 | if (PTRS_PER_PMD > 1) | |
256 | for (i = 0; i < USER_PTRS_PER_PGD; ++i) | |
257 | kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1)); | |
e0da382c | 258 | /* in the non-PAE case, free_pgtables() clears user pgd entries */ |
1da177e4 LT |
259 | kmem_cache_free(pgd_cache, pgd); |
260 | } |