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Commit | Line | Data |
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9f4c815c IM |
1 | /* |
2 | * Copyright 2002 Andi Kleen, SuSE Labs. | |
1da177e4 | 3 | * Thanks to Ben LaHaise for precious feedback. |
9f4c815c | 4 | */ |
1da177e4 | 5 | |
1da177e4 LT |
6 | #include <linux/highmem.h> |
7 | #include <linux/module.h> | |
9f4c815c | 8 | #include <linux/sched.h> |
1da177e4 | 9 | #include <linux/slab.h> |
9f4c815c IM |
10 | #include <linux/mm.h> |
11 | ||
1da177e4 LT |
12 | #include <asm/processor.h> |
13 | #include <asm/tlbflush.h> | |
f8af095d | 14 | #include <asm/sections.h> |
9f4c815c IM |
15 | #include <asm/uaccess.h> |
16 | #include <asm/pgalloc.h> | |
1da177e4 | 17 | |
f0646e43 | 18 | pte_t *lookup_address(unsigned long address, int *level) |
9f4c815c | 19 | { |
1da177e4 LT |
20 | pgd_t *pgd = pgd_offset_k(address); |
21 | pud_t *pud; | |
22 | pmd_t *pmd; | |
9f4c815c | 23 | |
1da177e4 LT |
24 | if (pgd_none(*pgd)) |
25 | return NULL; | |
26 | pud = pud_offset(pgd, address); | |
27 | if (pud_none(*pud)) | |
28 | return NULL; | |
29 | pmd = pmd_offset(pud, address); | |
30 | if (pmd_none(*pmd)) | |
31 | return NULL; | |
f0646e43 | 32 | *level = 2; |
1da177e4 LT |
33 | if (pmd_large(*pmd)) |
34 | return (pte_t *)pmd; | |
f0646e43 | 35 | *level = 3; |
1da177e4 | 36 | |
9f4c815c IM |
37 | return pte_offset_kernel(pmd, address); |
38 | } | |
39 | ||
9a3dc780 | 40 | static void __set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte) |
9f4c815c | 41 | { |
9f4c815c | 42 | struct page *page; |
1da177e4 | 43 | |
9f4c815c IM |
44 | /* change init_mm */ |
45 | set_pte_atomic(kpte, pte); | |
5311ab62 | 46 | if (SHARED_KERNEL_PMD) |
1da177e4 LT |
47 | return; |
48 | ||
1da177e4 LT |
49 | for (page = pgd_list; page; page = (struct page *)page->index) { |
50 | pgd_t *pgd; | |
51 | pud_t *pud; | |
52 | pmd_t *pmd; | |
9f4c815c | 53 | |
1da177e4 LT |
54 | pgd = (pgd_t *)page_address(page) + pgd_index(address); |
55 | pud = pud_offset(pgd, address); | |
56 | pmd = pmd_offset(pud, address); | |
57 | set_pte_atomic((pte_t *)pmd, pte); | |
58 | } | |
1da177e4 LT |
59 | } |
60 | ||
7afe15b9 | 61 | static int split_large_page(pte_t *kpte, unsigned long address) |
bb5c2dbd | 62 | { |
7afe15b9 | 63 | pgprot_t ref_prot = pte_pgprot(pte_clrhuge(*kpte)); |
12d6f21e | 64 | gfp_t gfp_flags = GFP_KERNEL; |
9a3dc780 | 65 | unsigned long flags; |
bb5c2dbd IM |
66 | unsigned long addr; |
67 | pte_t *pbase, *tmp; | |
68 | struct page *base; | |
7afe15b9 | 69 | int i, level; |
bb5c2dbd | 70 | |
12d6f21e IM |
71 | #ifdef CONFIG_DEBUG_PAGEALLOC |
72 | gfp_flags = GFP_ATOMIC; | |
73 | #endif | |
74 | base = alloc_pages(gfp_flags, 0); | |
bb5c2dbd IM |
75 | if (!base) |
76 | return -ENOMEM; | |
77 | ||
9a3dc780 | 78 | spin_lock_irqsave(&pgd_lock, flags); |
bb5c2dbd IM |
79 | /* |
80 | * Check for races, another CPU might have split this page | |
81 | * up for us already: | |
82 | */ | |
83 | tmp = lookup_address(address, &level); | |
5508a748 IM |
84 | if (tmp != kpte) { |
85 | WARN_ON_ONCE(1); | |
bb5c2dbd | 86 | goto out_unlock; |
5508a748 | 87 | } |
bb5c2dbd IM |
88 | |
89 | address = __pa(address); | |
90 | addr = address & LARGE_PAGE_MASK; | |
91 | pbase = (pte_t *)page_address(base); | |
92 | paravirt_alloc_pt(&init_mm, page_to_pfn(base)); | |
93 | ||
94 | for (i = 0; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE) | |
95 | set_pte(&pbase[i], pfn_pte(addr >> PAGE_SHIFT, ref_prot)); | |
96 | ||
97 | /* | |
98 | * Install the new, split up pagetable: | |
99 | */ | |
9a3dc780 | 100 | __set_pmd_pte(kpte, address, mk_pte(base, ref_prot)); |
bb5c2dbd IM |
101 | base = NULL; |
102 | ||
103 | out_unlock: | |
9a3dc780 | 104 | spin_unlock_irqrestore(&pgd_lock, flags); |
bb5c2dbd IM |
105 | |
106 | if (base) | |
107 | __free_pages(base, 0); | |
108 | ||
109 | return 0; | |
110 | } | |
111 | ||
9f4c815c IM |
112 | static int __change_page_attr(struct page *page, pgprot_t prot) |
113 | { | |
1da177e4 | 114 | struct page *kpte_page; |
9f4c815c | 115 | unsigned long address; |
bb5c2dbd | 116 | int level, err = 0; |
9f4c815c | 117 | pte_t *kpte; |
1da177e4 LT |
118 | |
119 | BUG_ON(PageHighMem(page)); | |
120 | address = (unsigned long)page_address(page); | |
121 | ||
97f99fed | 122 | repeat: |
f0646e43 | 123 | kpte = lookup_address(address, &level); |
1da177e4 LT |
124 | if (!kpte) |
125 | return -EINVAL; | |
9f4c815c | 126 | |
1da177e4 | 127 | kpte_page = virt_to_page(kpte); |
65d2f0bc AK |
128 | BUG_ON(PageLRU(kpte_page)); |
129 | BUG_ON(PageCompound(kpte_page)); | |
130 | ||
1da177e4 | 131 | /* |
78c94aba IM |
132 | * Better fail early if someone sets the kernel text to NX. |
133 | * Does not cover __inittext | |
1da177e4 | 134 | */ |
78c94aba IM |
135 | BUG_ON(address >= (unsigned long)&_text && |
136 | address < (unsigned long)&_etext && | |
137 | (pgprot_val(prot) & _PAGE_NX)); | |
65d2f0bc | 138 | |
78c94aba | 139 | if (level == 3) { |
7afe15b9 | 140 | set_pte_atomic(kpte, mk_pte(page, canon_pgprot(prot))); |
78c94aba | 141 | } else { |
7afe15b9 | 142 | err = split_large_page(kpte, address); |
bb5c2dbd IM |
143 | if (!err) |
144 | goto repeat; | |
1da177e4 | 145 | } |
bb5c2dbd | 146 | return err; |
9f4c815c | 147 | } |
1da177e4 | 148 | |
1da177e4 LT |
149 | /* |
150 | * Change the page attributes of an page in the linear mapping. | |
151 | * | |
152 | * This should be used when a page is mapped with a different caching policy | |
153 | * than write-back somewhere - some CPUs do not like it when mappings with | |
154 | * different caching policies exist. This changes the page attributes of the | |
155 | * in kernel linear mapping too. | |
9f4c815c | 156 | * |
1da177e4 LT |
157 | * The caller needs to ensure that there are no conflicting mappings elsewhere. |
158 | * This function only deals with the kernel linear map. | |
9f4c815c | 159 | * |
1da177e4 LT |
160 | * Caller must call global_flush_tlb() after this. |
161 | */ | |
162 | int change_page_attr(struct page *page, int numpages, pgprot_t prot) | |
163 | { | |
9f4c815c | 164 | int err = 0, i; |
1da177e4 | 165 | |
9f4c815c | 166 | for (i = 0; i < numpages; i++, page++) { |
1da177e4 | 167 | err = __change_page_attr(page, prot); |
9f4c815c IM |
168 | if (err) |
169 | break; | |
170 | } | |
9f4c815c | 171 | |
1da177e4 LT |
172 | return err; |
173 | } | |
9f4c815c | 174 | EXPORT_SYMBOL(change_page_attr); |
1da177e4 | 175 | |
78c94aba | 176 | int change_page_attr_addr(unsigned long addr, int numpages, pgprot_t prot) |
626ab0e6 | 177 | { |
78c94aba | 178 | int i; |
5508a748 | 179 | unsigned long pfn = (__pa(addr) >> PAGE_SHIFT); |
1da177e4 | 180 | |
78c94aba IM |
181 | for (i = 0; i < numpages; i++) { |
182 | if (!pfn_valid(pfn + i)) { | |
5508a748 | 183 | WARN_ON_ONCE(1); |
78c94aba IM |
184 | break; |
185 | } else { | |
186 | int level; | |
187 | pte_t *pte = lookup_address(addr + i*PAGE_SIZE, &level); | |
5508a748 | 188 | BUG_ON(pte && pte_none(*pte)); |
78c94aba IM |
189 | } |
190 | } | |
5508a748 | 191 | |
78c94aba IM |
192 | return change_page_attr(virt_to_page(addr), i, prot); |
193 | } | |
194 | ||
195 | static void flush_kernel_map(void *arg) | |
196 | { | |
197 | /* | |
198 | * Flush all to work around Errata in early athlons regarding | |
199 | * large page flushing. | |
200 | */ | |
201 | __flush_tlb_all(); | |
202 | ||
203 | if (boot_cpu_data.x86_model >= 4) | |
204 | wbinvd(); | |
205 | } | |
206 | ||
207 | void global_flush_tlb(void) | |
208 | { | |
1da177e4 LT |
209 | BUG_ON(irqs_disabled()); |
210 | ||
78c94aba | 211 | on_each_cpu(flush_kernel_map, NULL, 1, 1); |
626ab0e6 | 212 | } |
9f4c815c | 213 | EXPORT_SYMBOL(global_flush_tlb); |
1da177e4 LT |
214 | |
215 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
216 | void kernel_map_pages(struct page *page, int numpages, int enable) | |
217 | { | |
218 | if (PageHighMem(page)) | |
219 | return; | |
9f4c815c | 220 | if (!enable) { |
f9b8404c IM |
221 | debug_check_no_locks_freed(page_address(page), |
222 | numpages * PAGE_SIZE); | |
9f4c815c | 223 | } |
de5097c2 | 224 | |
12d6f21e IM |
225 | /* |
226 | * If page allocator is not up yet then do not call c_p_a(): | |
227 | */ | |
228 | if (!debug_pagealloc_enabled) | |
229 | return; | |
230 | ||
9f4c815c IM |
231 | /* |
232 | * the return value is ignored - the calls cannot fail, | |
1da177e4 LT |
233 | * large pages are disabled at boot time. |
234 | */ | |
235 | change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0)); | |
9f4c815c IM |
236 | |
237 | /* | |
238 | * we should perform an IPI and flush all tlbs, | |
1da177e4 LT |
239 | * but that can deadlock->flush only current cpu. |
240 | */ | |
241 | __flush_tlb_all(); | |
242 | } | |
243 | #endif |