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1da177e4 LT |
1 | /* |
2 | * IA-64 Huge TLB Page Support for Kernel. | |
3 | * | |
4 | * Copyright (C) 2002-2004 Rohit Seth <rohit.seth@intel.com> | |
5 | * Copyright (C) 2003-2004 Ken Chen <kenneth.w.chen@intel.com> | |
6 | * | |
7 | * Sep, 2003: add numa support | |
8 | * Feb, 2004: dynamic hugetlb page size via boot parameter | |
9 | */ | |
10 | ||
11 | #include <linux/config.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/fs.h> | |
14 | #include <linux/mm.h> | |
15 | #include <linux/hugetlb.h> | |
16 | #include <linux/pagemap.h> | |
17 | #include <linux/smp_lock.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/sysctl.h> | |
20 | #include <asm/mman.h> | |
21 | #include <asm/pgalloc.h> | |
22 | #include <asm/tlb.h> | |
23 | #include <asm/tlbflush.h> | |
24 | ||
25 | unsigned int hpage_shift=HPAGE_SHIFT_DEFAULT; | |
26 | ||
27 | static pte_t * | |
28 | huge_pte_alloc (struct mm_struct *mm, unsigned long addr) | |
29 | { | |
30 | unsigned long taddr = htlbpage_to_page(addr); | |
31 | pgd_t *pgd; | |
32 | pud_t *pud; | |
33 | pmd_t *pmd; | |
34 | pte_t *pte = NULL; | |
35 | ||
36 | pgd = pgd_offset(mm, taddr); | |
37 | pud = pud_alloc(mm, pgd, taddr); | |
38 | if (pud) { | |
39 | pmd = pmd_alloc(mm, pud, taddr); | |
40 | if (pmd) | |
41 | pte = pte_alloc_map(mm, pmd, taddr); | |
42 | } | |
43 | return pte; | |
44 | } | |
45 | ||
46 | static pte_t * | |
47 | huge_pte_offset (struct mm_struct *mm, unsigned long addr) | |
48 | { | |
49 | unsigned long taddr = htlbpage_to_page(addr); | |
50 | pgd_t *pgd; | |
51 | pud_t *pud; | |
52 | pmd_t *pmd; | |
53 | pte_t *pte = NULL; | |
54 | ||
55 | pgd = pgd_offset(mm, taddr); | |
56 | if (pgd_present(*pgd)) { | |
57 | pud = pud_offset(pgd, taddr); | |
58 | if (pud_present(*pud)) { | |
59 | pmd = pmd_offset(pud, taddr); | |
60 | if (pmd_present(*pmd)) | |
61 | pte = pte_offset_map(pmd, taddr); | |
62 | } | |
63 | } | |
64 | ||
65 | return pte; | |
66 | } | |
67 | ||
68 | #define mk_pte_huge(entry) { pte_val(entry) |= _PAGE_P; } | |
69 | ||
70 | static void | |
71 | set_huge_pte (struct mm_struct *mm, struct vm_area_struct *vma, | |
72 | struct page *page, pte_t * page_table, int write_access) | |
73 | { | |
74 | pte_t entry; | |
75 | ||
76 | add_mm_counter(mm, rss, HPAGE_SIZE / PAGE_SIZE); | |
77 | if (write_access) { | |
78 | entry = | |
79 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); | |
80 | } else | |
81 | entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot)); | |
82 | entry = pte_mkyoung(entry); | |
83 | mk_pte_huge(entry); | |
84 | set_pte(page_table, entry); | |
85 | return; | |
86 | } | |
87 | /* | |
88 | * This function checks for proper alignment of input addr and len parameters. | |
89 | */ | |
90 | int is_aligned_hugepage_range(unsigned long addr, unsigned long len) | |
91 | { | |
92 | if (len & ~HPAGE_MASK) | |
93 | return -EINVAL; | |
94 | if (addr & ~HPAGE_MASK) | |
95 | return -EINVAL; | |
96 | if (REGION_NUMBER(addr) != REGION_HPAGE) | |
97 | return -EINVAL; | |
98 | ||
99 | return 0; | |
100 | } | |
101 | ||
102 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, | |
103 | struct vm_area_struct *vma) | |
104 | { | |
105 | pte_t *src_pte, *dst_pte, entry; | |
106 | struct page *ptepage; | |
107 | unsigned long addr = vma->vm_start; | |
108 | unsigned long end = vma->vm_end; | |
109 | ||
110 | while (addr < end) { | |
111 | dst_pte = huge_pte_alloc(dst, addr); | |
112 | if (!dst_pte) | |
113 | goto nomem; | |
114 | src_pte = huge_pte_offset(src, addr); | |
115 | entry = *src_pte; | |
116 | ptepage = pte_page(entry); | |
117 | get_page(ptepage); | |
118 | set_pte(dst_pte, entry); | |
119 | add_mm_counter(dst, rss, HPAGE_SIZE / PAGE_SIZE); | |
120 | addr += HPAGE_SIZE; | |
121 | } | |
122 | return 0; | |
123 | nomem: | |
124 | return -ENOMEM; | |
125 | } | |
126 | ||
127 | int | |
128 | follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, | |
129 | struct page **pages, struct vm_area_struct **vmas, | |
130 | unsigned long *st, int *length, int i) | |
131 | { | |
132 | pte_t *ptep, pte; | |
133 | unsigned long start = *st; | |
134 | unsigned long pstart; | |
135 | int len = *length; | |
136 | struct page *page; | |
137 | ||
138 | do { | |
139 | pstart = start & HPAGE_MASK; | |
140 | ptep = huge_pte_offset(mm, start); | |
141 | pte = *ptep; | |
142 | ||
143 | back1: | |
144 | page = pte_page(pte); | |
145 | if (pages) { | |
146 | page += ((start & ~HPAGE_MASK) >> PAGE_SHIFT); | |
147 | get_page(page); | |
148 | pages[i] = page; | |
149 | } | |
150 | if (vmas) | |
151 | vmas[i] = vma; | |
152 | i++; | |
153 | len--; | |
154 | start += PAGE_SIZE; | |
155 | if (((start & HPAGE_MASK) == pstart) && len && | |
156 | (start < vma->vm_end)) | |
157 | goto back1; | |
158 | } while (len && start < vma->vm_end); | |
159 | *length = len; | |
160 | *st = start; | |
161 | return i; | |
162 | } | |
163 | ||
164 | struct page *follow_huge_addr(struct mm_struct *mm, unsigned long addr, int write) | |
165 | { | |
166 | struct page *page; | |
167 | pte_t *ptep; | |
168 | ||
169 | if (REGION_NUMBER(addr) != REGION_HPAGE) | |
170 | return ERR_PTR(-EINVAL); | |
171 | ||
172 | ptep = huge_pte_offset(mm, addr); | |
173 | if (!ptep || pte_none(*ptep)) | |
174 | return NULL; | |
175 | page = pte_page(*ptep); | |
176 | page += ((addr & ~HPAGE_MASK) >> PAGE_SHIFT); | |
177 | return page; | |
178 | } | |
179 | int pmd_huge(pmd_t pmd) | |
180 | { | |
181 | return 0; | |
182 | } | |
183 | struct page * | |
184 | follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write) | |
185 | { | |
186 | return NULL; | |
187 | } | |
188 | ||
189 | /* | |
190 | * Same as generic free_pgtables(), except constant PGDIR_* and pgd_offset | |
191 | * are hugetlb region specific. | |
192 | */ | |
193 | void hugetlb_free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *prev, | |
194 | unsigned long start, unsigned long end) | |
195 | { | |
196 | unsigned long first = start & HUGETLB_PGDIR_MASK; | |
197 | unsigned long last = end + HUGETLB_PGDIR_SIZE - 1; | |
198 | struct mm_struct *mm = tlb->mm; | |
199 | ||
200 | if (!prev) { | |
201 | prev = mm->mmap; | |
202 | if (!prev) | |
203 | goto no_mmaps; | |
204 | if (prev->vm_end > start) { | |
205 | if (last > prev->vm_start) | |
206 | last = prev->vm_start; | |
207 | goto no_mmaps; | |
208 | } | |
209 | } | |
210 | for (;;) { | |
211 | struct vm_area_struct *next = prev->vm_next; | |
212 | ||
213 | if (next) { | |
214 | if (next->vm_start < start) { | |
215 | prev = next; | |
216 | continue; | |
217 | } | |
218 | if (last > next->vm_start) | |
219 | last = next->vm_start; | |
220 | } | |
221 | if (prev->vm_end > first) | |
222 | first = prev->vm_end; | |
223 | break; | |
224 | } | |
225 | no_mmaps: | |
226 | if (last < first) /* for arches with discontiguous pgd indices */ | |
227 | return; | |
228 | clear_page_range(tlb, first, last); | |
229 | } | |
230 | ||
231 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, unsigned long end) | |
232 | { | |
233 | struct mm_struct *mm = vma->vm_mm; | |
234 | unsigned long address; | |
235 | pte_t *pte; | |
236 | struct page *page; | |
237 | ||
238 | BUG_ON(start & (HPAGE_SIZE - 1)); | |
239 | BUG_ON(end & (HPAGE_SIZE - 1)); | |
240 | ||
241 | for (address = start; address < end; address += HPAGE_SIZE) { | |
242 | pte = huge_pte_offset(mm, address); | |
243 | if (pte_none(*pte)) | |
244 | continue; | |
245 | page = pte_page(*pte); | |
246 | put_page(page); | |
247 | pte_clear(mm, address, pte); | |
248 | } | |
249 | add_mm_counter(mm, rss, - ((end - start) >> PAGE_SHIFT)); | |
250 | flush_tlb_range(vma, start, end); | |
251 | } | |
252 | ||
253 | int hugetlb_prefault(struct address_space *mapping, struct vm_area_struct *vma) | |
254 | { | |
255 | struct mm_struct *mm = current->mm; | |
256 | unsigned long addr; | |
257 | int ret = 0; | |
258 | ||
259 | BUG_ON(vma->vm_start & ~HPAGE_MASK); | |
260 | BUG_ON(vma->vm_end & ~HPAGE_MASK); | |
261 | ||
262 | spin_lock(&mm->page_table_lock); | |
263 | for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) { | |
264 | unsigned long idx; | |
265 | pte_t *pte = huge_pte_alloc(mm, addr); | |
266 | struct page *page; | |
267 | ||
268 | if (!pte) { | |
269 | ret = -ENOMEM; | |
270 | goto out; | |
271 | } | |
272 | if (!pte_none(*pte)) | |
273 | continue; | |
274 | ||
275 | idx = ((addr - vma->vm_start) >> HPAGE_SHIFT) | |
276 | + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); | |
277 | page = find_get_page(mapping, idx); | |
278 | if (!page) { | |
279 | /* charge the fs quota first */ | |
280 | if (hugetlb_get_quota(mapping)) { | |
281 | ret = -ENOMEM; | |
282 | goto out; | |
283 | } | |
284 | page = alloc_huge_page(); | |
285 | if (!page) { | |
286 | hugetlb_put_quota(mapping); | |
287 | ret = -ENOMEM; | |
288 | goto out; | |
289 | } | |
290 | ret = add_to_page_cache(page, mapping, idx, GFP_ATOMIC); | |
291 | if (! ret) { | |
292 | unlock_page(page); | |
293 | } else { | |
294 | hugetlb_put_quota(mapping); | |
295 | page_cache_release(page); | |
296 | goto out; | |
297 | } | |
298 | } | |
299 | set_huge_pte(mm, vma, page, pte, vma->vm_flags & VM_WRITE); | |
300 | } | |
301 | out: | |
302 | spin_unlock(&mm->page_table_lock); | |
303 | return ret; | |
304 | } | |
305 | ||
306 | unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, | |
307 | unsigned long pgoff, unsigned long flags) | |
308 | { | |
309 | struct vm_area_struct *vmm; | |
310 | ||
311 | if (len > RGN_MAP_LIMIT) | |
312 | return -ENOMEM; | |
313 | if (len & ~HPAGE_MASK) | |
314 | return -EINVAL; | |
315 | /* This code assumes that REGION_HPAGE != 0. */ | |
316 | if ((REGION_NUMBER(addr) != REGION_HPAGE) || (addr & (HPAGE_SIZE - 1))) | |
317 | addr = HPAGE_REGION_BASE; | |
318 | else | |
319 | addr = ALIGN(addr, HPAGE_SIZE); | |
320 | for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) { | |
321 | /* At this point: (!vmm || addr < vmm->vm_end). */ | |
322 | if (REGION_OFFSET(addr) + len > RGN_MAP_LIMIT) | |
323 | return -ENOMEM; | |
324 | if (!vmm || (addr + len) <= vmm->vm_start) | |
325 | return addr; | |
326 | addr = ALIGN(vmm->vm_end, HPAGE_SIZE); | |
327 | } | |
328 | } | |
329 | ||
330 | static int __init hugetlb_setup_sz(char *str) | |
331 | { | |
332 | u64 tr_pages; | |
333 | unsigned long long size; | |
334 | ||
335 | if (ia64_pal_vm_page_size(&tr_pages, NULL) != 0) | |
336 | /* | |
337 | * shouldn't happen, but just in case. | |
338 | */ | |
339 | tr_pages = 0x15557000UL; | |
340 | ||
341 | size = memparse(str, &str); | |
342 | if (*str || (size & (size-1)) || !(tr_pages & size) || | |
343 | size <= PAGE_SIZE || | |
344 | size >= (1UL << PAGE_SHIFT << MAX_ORDER)) { | |
345 | printk(KERN_WARNING "Invalid huge page size specified\n"); | |
346 | return 1; | |
347 | } | |
348 | ||
349 | hpage_shift = __ffs(size); | |
350 | /* | |
351 | * boot cpu already executed ia64_mmu_init, and has HPAGE_SHIFT_DEFAULT | |
352 | * override here with new page shift. | |
353 | */ | |
354 | ia64_set_rr(HPAGE_REGION_BASE, hpage_shift << 2); | |
355 | return 1; | |
356 | } | |
357 | __setup("hugepagesz=", hugetlb_setup_sz); |