Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Generic hugetlb support. | |
3 | * (C) William Irwin, April 2004 | |
4 | */ | |
5 | #include <linux/gfp.h> | |
6 | #include <linux/list.h> | |
7 | #include <linux/init.h> | |
8 | #include <linux/module.h> | |
9 | #include <linux/mm.h> | |
1da177e4 LT |
10 | #include <linux/sysctl.h> |
11 | #include <linux/highmem.h> | |
12 | #include <linux/nodemask.h> | |
63551ae0 | 13 | #include <linux/pagemap.h> |
5da7ca86 | 14 | #include <linux/mempolicy.h> |
aea47ff3 | 15 | #include <linux/cpuset.h> |
3935baa9 | 16 | #include <linux/mutex.h> |
5da7ca86 | 17 | |
63551ae0 DG |
18 | #include <asm/page.h> |
19 | #include <asm/pgtable.h> | |
20 | ||
21 | #include <linux/hugetlb.h> | |
7835e98b | 22 | #include "internal.h" |
1da177e4 LT |
23 | |
24 | const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; | |
a43a8c39 | 25 | static unsigned long nr_huge_pages, free_huge_pages, resv_huge_pages; |
1da177e4 LT |
26 | unsigned long max_huge_pages; |
27 | static struct list_head hugepage_freelists[MAX_NUMNODES]; | |
28 | static unsigned int nr_huge_pages_node[MAX_NUMNODES]; | |
29 | static unsigned int free_huge_pages_node[MAX_NUMNODES]; | |
3935baa9 DG |
30 | /* |
31 | * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages | |
32 | */ | |
33 | static DEFINE_SPINLOCK(hugetlb_lock); | |
0bd0f9fb | 34 | |
79ac6ba4 DG |
35 | static void clear_huge_page(struct page *page, unsigned long addr) |
36 | { | |
37 | int i; | |
38 | ||
39 | might_sleep(); | |
40 | for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); i++) { | |
41 | cond_resched(); | |
42 | clear_user_highpage(page + i, addr); | |
43 | } | |
44 | } | |
45 | ||
46 | static void copy_huge_page(struct page *dst, struct page *src, | |
9de455b2 | 47 | unsigned long addr, struct vm_area_struct *vma) |
79ac6ba4 DG |
48 | { |
49 | int i; | |
50 | ||
51 | might_sleep(); | |
52 | for (i = 0; i < HPAGE_SIZE/PAGE_SIZE; i++) { | |
53 | cond_resched(); | |
9de455b2 | 54 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); |
79ac6ba4 DG |
55 | } |
56 | } | |
57 | ||
1da177e4 LT |
58 | static void enqueue_huge_page(struct page *page) |
59 | { | |
60 | int nid = page_to_nid(page); | |
61 | list_add(&page->lru, &hugepage_freelists[nid]); | |
62 | free_huge_pages++; | |
63 | free_huge_pages_node[nid]++; | |
64 | } | |
65 | ||
5da7ca86 CL |
66 | static struct page *dequeue_huge_page(struct vm_area_struct *vma, |
67 | unsigned long address) | |
1da177e4 LT |
68 | { |
69 | int nid = numa_node_id(); | |
70 | struct page *page = NULL; | |
5da7ca86 | 71 | struct zonelist *zonelist = huge_zonelist(vma, address); |
96df9333 | 72 | struct zone **z; |
1da177e4 | 73 | |
96df9333 | 74 | for (z = zonelist->zones; *z; z++) { |
89fa3024 | 75 | nid = zone_to_nid(*z); |
02a0e53d | 76 | if (cpuset_zone_allowed_softwall(*z, GFP_HIGHUSER) && |
aea47ff3 | 77 | !list_empty(&hugepage_freelists[nid])) |
96df9333 | 78 | break; |
1da177e4 | 79 | } |
96df9333 CL |
80 | |
81 | if (*z) { | |
1da177e4 LT |
82 | page = list_entry(hugepage_freelists[nid].next, |
83 | struct page, lru); | |
84 | list_del(&page->lru); | |
85 | free_huge_pages--; | |
86 | free_huge_pages_node[nid]--; | |
87 | } | |
88 | return page; | |
89 | } | |
90 | ||
27a85ef1 DG |
91 | static void free_huge_page(struct page *page) |
92 | { | |
93 | BUG_ON(page_count(page)); | |
94 | ||
95 | INIT_LIST_HEAD(&page->lru); | |
96 | ||
97 | spin_lock(&hugetlb_lock); | |
98 | enqueue_huge_page(page); | |
99 | spin_unlock(&hugetlb_lock); | |
100 | } | |
101 | ||
a482289d | 102 | static int alloc_fresh_huge_page(void) |
1da177e4 LT |
103 | { |
104 | static int nid = 0; | |
105 | struct page *page; | |
106 | page = alloc_pages_node(nid, GFP_HIGHUSER|__GFP_COMP|__GFP_NOWARN, | |
107 | HUGETLB_PAGE_ORDER); | |
fdb7cc59 PJ |
108 | nid = next_node(nid, node_online_map); |
109 | if (nid == MAX_NUMNODES) | |
110 | nid = first_node(node_online_map); | |
1da177e4 | 111 | if (page) { |
33f2ef89 | 112 | set_compound_page_dtor(page, free_huge_page); |
0bd0f9fb | 113 | spin_lock(&hugetlb_lock); |
1da177e4 LT |
114 | nr_huge_pages++; |
115 | nr_huge_pages_node[page_to_nid(page)]++; | |
0bd0f9fb | 116 | spin_unlock(&hugetlb_lock); |
a482289d NP |
117 | put_page(page); /* free it into the hugepage allocator */ |
118 | return 1; | |
1da177e4 | 119 | } |
a482289d | 120 | return 0; |
1da177e4 LT |
121 | } |
122 | ||
27a85ef1 DG |
123 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
124 | unsigned long addr) | |
1da177e4 LT |
125 | { |
126 | struct page *page; | |
1da177e4 LT |
127 | |
128 | spin_lock(&hugetlb_lock); | |
a43a8c39 CK |
129 | if (vma->vm_flags & VM_MAYSHARE) |
130 | resv_huge_pages--; | |
131 | else if (free_huge_pages <= resv_huge_pages) | |
132 | goto fail; | |
b45b5bd6 DG |
133 | |
134 | page = dequeue_huge_page(vma, addr); | |
135 | if (!page) | |
136 | goto fail; | |
137 | ||
1da177e4 | 138 | spin_unlock(&hugetlb_lock); |
7835e98b | 139 | set_page_refcounted(page); |
1da177e4 | 140 | return page; |
b45b5bd6 | 141 | |
a43a8c39 | 142 | fail: |
ace4bd29 KC |
143 | if (vma->vm_flags & VM_MAYSHARE) |
144 | resv_huge_pages++; | |
b45b5bd6 DG |
145 | spin_unlock(&hugetlb_lock); |
146 | return NULL; | |
147 | } | |
148 | ||
1da177e4 LT |
149 | static int __init hugetlb_init(void) |
150 | { | |
151 | unsigned long i; | |
1da177e4 | 152 | |
3c726f8d BH |
153 | if (HPAGE_SHIFT == 0) |
154 | return 0; | |
155 | ||
1da177e4 LT |
156 | for (i = 0; i < MAX_NUMNODES; ++i) |
157 | INIT_LIST_HEAD(&hugepage_freelists[i]); | |
158 | ||
159 | for (i = 0; i < max_huge_pages; ++i) { | |
a482289d | 160 | if (!alloc_fresh_huge_page()) |
1da177e4 | 161 | break; |
1da177e4 LT |
162 | } |
163 | max_huge_pages = free_huge_pages = nr_huge_pages = i; | |
164 | printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages); | |
165 | return 0; | |
166 | } | |
167 | module_init(hugetlb_init); | |
168 | ||
169 | static int __init hugetlb_setup(char *s) | |
170 | { | |
171 | if (sscanf(s, "%lu", &max_huge_pages) <= 0) | |
172 | max_huge_pages = 0; | |
173 | return 1; | |
174 | } | |
175 | __setup("hugepages=", hugetlb_setup); | |
176 | ||
177 | #ifdef CONFIG_SYSCTL | |
178 | static void update_and_free_page(struct page *page) | |
179 | { | |
180 | int i; | |
181 | nr_huge_pages--; | |
4415cc8d | 182 | nr_huge_pages_node[page_to_nid(page)]--; |
1da177e4 LT |
183 | for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) { |
184 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | | |
185 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | | |
186 | 1 << PG_private | 1<< PG_writeback); | |
1da177e4 | 187 | } |
a482289d | 188 | page[1].lru.next = NULL; |
7835e98b | 189 | set_page_refcounted(page); |
1da177e4 LT |
190 | __free_pages(page, HUGETLB_PAGE_ORDER); |
191 | } | |
192 | ||
193 | #ifdef CONFIG_HIGHMEM | |
194 | static void try_to_free_low(unsigned long count) | |
195 | { | |
4415cc8d CL |
196 | int i; |
197 | ||
1da177e4 LT |
198 | for (i = 0; i < MAX_NUMNODES; ++i) { |
199 | struct page *page, *next; | |
200 | list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) { | |
201 | if (PageHighMem(page)) | |
202 | continue; | |
203 | list_del(&page->lru); | |
204 | update_and_free_page(page); | |
1da177e4 | 205 | free_huge_pages--; |
4415cc8d | 206 | free_huge_pages_node[page_to_nid(page)]--; |
1da177e4 LT |
207 | if (count >= nr_huge_pages) |
208 | return; | |
209 | } | |
210 | } | |
211 | } | |
212 | #else | |
213 | static inline void try_to_free_low(unsigned long count) | |
214 | { | |
215 | } | |
216 | #endif | |
217 | ||
218 | static unsigned long set_max_huge_pages(unsigned long count) | |
219 | { | |
220 | while (count > nr_huge_pages) { | |
a482289d | 221 | if (!alloc_fresh_huge_page()) |
1da177e4 | 222 | return nr_huge_pages; |
1da177e4 LT |
223 | } |
224 | if (count >= nr_huge_pages) | |
225 | return nr_huge_pages; | |
226 | ||
227 | spin_lock(&hugetlb_lock); | |
a43a8c39 | 228 | count = max(count, resv_huge_pages); |
1da177e4 LT |
229 | try_to_free_low(count); |
230 | while (count < nr_huge_pages) { | |
5da7ca86 | 231 | struct page *page = dequeue_huge_page(NULL, 0); |
1da177e4 LT |
232 | if (!page) |
233 | break; | |
234 | update_and_free_page(page); | |
235 | } | |
236 | spin_unlock(&hugetlb_lock); | |
237 | return nr_huge_pages; | |
238 | } | |
239 | ||
240 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, | |
241 | struct file *file, void __user *buffer, | |
242 | size_t *length, loff_t *ppos) | |
243 | { | |
244 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); | |
245 | max_huge_pages = set_max_huge_pages(max_huge_pages); | |
246 | return 0; | |
247 | } | |
248 | #endif /* CONFIG_SYSCTL */ | |
249 | ||
250 | int hugetlb_report_meminfo(char *buf) | |
251 | { | |
252 | return sprintf(buf, | |
253 | "HugePages_Total: %5lu\n" | |
254 | "HugePages_Free: %5lu\n" | |
a43a8c39 | 255 | "HugePages_Rsvd: %5lu\n" |
1da177e4 LT |
256 | "Hugepagesize: %5lu kB\n", |
257 | nr_huge_pages, | |
258 | free_huge_pages, | |
a43a8c39 | 259 | resv_huge_pages, |
1da177e4 LT |
260 | HPAGE_SIZE/1024); |
261 | } | |
262 | ||
263 | int hugetlb_report_node_meminfo(int nid, char *buf) | |
264 | { | |
265 | return sprintf(buf, | |
266 | "Node %d HugePages_Total: %5u\n" | |
267 | "Node %d HugePages_Free: %5u\n", | |
268 | nid, nr_huge_pages_node[nid], | |
269 | nid, free_huge_pages_node[nid]); | |
270 | } | |
271 | ||
1da177e4 LT |
272 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
273 | unsigned long hugetlb_total_pages(void) | |
274 | { | |
275 | return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE); | |
276 | } | |
1da177e4 LT |
277 | |
278 | /* | |
279 | * We cannot handle pagefaults against hugetlb pages at all. They cause | |
280 | * handle_mm_fault() to try to instantiate regular-sized pages in the | |
281 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get | |
282 | * this far. | |
283 | */ | |
284 | static struct page *hugetlb_nopage(struct vm_area_struct *vma, | |
285 | unsigned long address, int *unused) | |
286 | { | |
287 | BUG(); | |
288 | return NULL; | |
289 | } | |
290 | ||
291 | struct vm_operations_struct hugetlb_vm_ops = { | |
292 | .nopage = hugetlb_nopage, | |
293 | }; | |
294 | ||
1e8f889b DG |
295 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
296 | int writable) | |
63551ae0 DG |
297 | { |
298 | pte_t entry; | |
299 | ||
1e8f889b | 300 | if (writable) { |
63551ae0 DG |
301 | entry = |
302 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); | |
303 | } else { | |
304 | entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot)); | |
305 | } | |
306 | entry = pte_mkyoung(entry); | |
307 | entry = pte_mkhuge(entry); | |
308 | ||
309 | return entry; | |
310 | } | |
311 | ||
1e8f889b DG |
312 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
313 | unsigned long address, pte_t *ptep) | |
314 | { | |
315 | pte_t entry; | |
316 | ||
317 | entry = pte_mkwrite(pte_mkdirty(*ptep)); | |
318 | ptep_set_access_flags(vma, address, ptep, entry, 1); | |
319 | update_mmu_cache(vma, address, entry); | |
320 | lazy_mmu_prot_update(entry); | |
321 | } | |
322 | ||
323 | ||
63551ae0 DG |
324 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
325 | struct vm_area_struct *vma) | |
326 | { | |
327 | pte_t *src_pte, *dst_pte, entry; | |
328 | struct page *ptepage; | |
1c59827d | 329 | unsigned long addr; |
1e8f889b DG |
330 | int cow; |
331 | ||
332 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; | |
63551ae0 | 333 | |
1c59827d | 334 | for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) { |
c74df32c HD |
335 | src_pte = huge_pte_offset(src, addr); |
336 | if (!src_pte) | |
337 | continue; | |
63551ae0 DG |
338 | dst_pte = huge_pte_alloc(dst, addr); |
339 | if (!dst_pte) | |
340 | goto nomem; | |
c74df32c | 341 | spin_lock(&dst->page_table_lock); |
1c59827d | 342 | spin_lock(&src->page_table_lock); |
c74df32c | 343 | if (!pte_none(*src_pte)) { |
1e8f889b DG |
344 | if (cow) |
345 | ptep_set_wrprotect(src, addr, src_pte); | |
1c59827d HD |
346 | entry = *src_pte; |
347 | ptepage = pte_page(entry); | |
348 | get_page(ptepage); | |
1c59827d HD |
349 | set_huge_pte_at(dst, addr, dst_pte, entry); |
350 | } | |
351 | spin_unlock(&src->page_table_lock); | |
c74df32c | 352 | spin_unlock(&dst->page_table_lock); |
63551ae0 DG |
353 | } |
354 | return 0; | |
355 | ||
356 | nomem: | |
357 | return -ENOMEM; | |
358 | } | |
359 | ||
502717f4 CK |
360 | void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
361 | unsigned long end) | |
63551ae0 DG |
362 | { |
363 | struct mm_struct *mm = vma->vm_mm; | |
364 | unsigned long address; | |
c7546f8f | 365 | pte_t *ptep; |
63551ae0 DG |
366 | pte_t pte; |
367 | struct page *page; | |
fe1668ae | 368 | struct page *tmp; |
c0a499c2 CK |
369 | /* |
370 | * A page gathering list, protected by per file i_mmap_lock. The | |
371 | * lock is used to avoid list corruption from multiple unmapping | |
372 | * of the same page since we are using page->lru. | |
373 | */ | |
fe1668ae | 374 | LIST_HEAD(page_list); |
63551ae0 DG |
375 | |
376 | WARN_ON(!is_vm_hugetlb_page(vma)); | |
377 | BUG_ON(start & ~HPAGE_MASK); | |
378 | BUG_ON(end & ~HPAGE_MASK); | |
379 | ||
508034a3 | 380 | spin_lock(&mm->page_table_lock); |
63551ae0 | 381 | for (address = start; address < end; address += HPAGE_SIZE) { |
c7546f8f | 382 | ptep = huge_pte_offset(mm, address); |
4c887265 | 383 | if (!ptep) |
c7546f8f DG |
384 | continue; |
385 | ||
39dde65c CK |
386 | if (huge_pmd_unshare(mm, &address, ptep)) |
387 | continue; | |
388 | ||
c7546f8f | 389 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
63551ae0 DG |
390 | if (pte_none(pte)) |
391 | continue; | |
c7546f8f | 392 | |
63551ae0 | 393 | page = pte_page(pte); |
6649a386 KC |
394 | if (pte_dirty(pte)) |
395 | set_page_dirty(page); | |
fe1668ae | 396 | list_add(&page->lru, &page_list); |
63551ae0 | 397 | } |
1da177e4 | 398 | spin_unlock(&mm->page_table_lock); |
508034a3 | 399 | flush_tlb_range(vma, start, end); |
fe1668ae CK |
400 | list_for_each_entry_safe(page, tmp, &page_list, lru) { |
401 | list_del(&page->lru); | |
402 | put_page(page); | |
403 | } | |
1da177e4 | 404 | } |
63551ae0 | 405 | |
502717f4 CK |
406 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
407 | unsigned long end) | |
408 | { | |
409 | /* | |
410 | * It is undesirable to test vma->vm_file as it should be non-null | |
411 | * for valid hugetlb area. However, vm_file will be NULL in the error | |
412 | * cleanup path of do_mmap_pgoff. When hugetlbfs ->mmap method fails, | |
413 | * do_mmap_pgoff() nullifies vma->vm_file before calling this function | |
414 | * to clean up. Since no pte has actually been setup, it is safe to | |
415 | * do nothing in this case. | |
416 | */ | |
417 | if (vma->vm_file) { | |
418 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); | |
419 | __unmap_hugepage_range(vma, start, end); | |
420 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); | |
421 | } | |
422 | } | |
423 | ||
1e8f889b DG |
424 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
425 | unsigned long address, pte_t *ptep, pte_t pte) | |
426 | { | |
427 | struct page *old_page, *new_page; | |
79ac6ba4 | 428 | int avoidcopy; |
1e8f889b DG |
429 | |
430 | old_page = pte_page(pte); | |
431 | ||
432 | /* If no-one else is actually using this page, avoid the copy | |
433 | * and just make the page writable */ | |
434 | avoidcopy = (page_count(old_page) == 1); | |
435 | if (avoidcopy) { | |
436 | set_huge_ptep_writable(vma, address, ptep); | |
437 | return VM_FAULT_MINOR; | |
438 | } | |
439 | ||
440 | page_cache_get(old_page); | |
5da7ca86 | 441 | new_page = alloc_huge_page(vma, address); |
1e8f889b DG |
442 | |
443 | if (!new_page) { | |
444 | page_cache_release(old_page); | |
0df420d8 | 445 | return VM_FAULT_OOM; |
1e8f889b DG |
446 | } |
447 | ||
448 | spin_unlock(&mm->page_table_lock); | |
9de455b2 | 449 | copy_huge_page(new_page, old_page, address, vma); |
1e8f889b DG |
450 | spin_lock(&mm->page_table_lock); |
451 | ||
452 | ptep = huge_pte_offset(mm, address & HPAGE_MASK); | |
453 | if (likely(pte_same(*ptep, pte))) { | |
454 | /* Break COW */ | |
455 | set_huge_pte_at(mm, address, ptep, | |
456 | make_huge_pte(vma, new_page, 1)); | |
457 | /* Make the old page be freed below */ | |
458 | new_page = old_page; | |
459 | } | |
460 | page_cache_release(new_page); | |
461 | page_cache_release(old_page); | |
462 | return VM_FAULT_MINOR; | |
463 | } | |
464 | ||
86e5216f | 465 | int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1e8f889b | 466 | unsigned long address, pte_t *ptep, int write_access) |
ac9b9c66 HD |
467 | { |
468 | int ret = VM_FAULT_SIGBUS; | |
4c887265 AL |
469 | unsigned long idx; |
470 | unsigned long size; | |
4c887265 AL |
471 | struct page *page; |
472 | struct address_space *mapping; | |
1e8f889b | 473 | pte_t new_pte; |
4c887265 | 474 | |
4c887265 AL |
475 | mapping = vma->vm_file->f_mapping; |
476 | idx = ((address - vma->vm_start) >> HPAGE_SHIFT) | |
477 | + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); | |
478 | ||
479 | /* | |
480 | * Use page lock to guard against racing truncation | |
481 | * before we get page_table_lock. | |
482 | */ | |
6bda666a CL |
483 | retry: |
484 | page = find_lock_page(mapping, idx); | |
485 | if (!page) { | |
ebed4bfc HD |
486 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
487 | if (idx >= size) | |
488 | goto out; | |
6bda666a CL |
489 | if (hugetlb_get_quota(mapping)) |
490 | goto out; | |
491 | page = alloc_huge_page(vma, address); | |
492 | if (!page) { | |
493 | hugetlb_put_quota(mapping); | |
0df420d8 | 494 | ret = VM_FAULT_OOM; |
6bda666a CL |
495 | goto out; |
496 | } | |
79ac6ba4 | 497 | clear_huge_page(page, address); |
ac9b9c66 | 498 | |
6bda666a CL |
499 | if (vma->vm_flags & VM_SHARED) { |
500 | int err; | |
501 | ||
502 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); | |
503 | if (err) { | |
504 | put_page(page); | |
505 | hugetlb_put_quota(mapping); | |
506 | if (err == -EEXIST) | |
507 | goto retry; | |
508 | goto out; | |
509 | } | |
510 | } else | |
511 | lock_page(page); | |
512 | } | |
1e8f889b | 513 | |
ac9b9c66 | 514 | spin_lock(&mm->page_table_lock); |
4c887265 AL |
515 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
516 | if (idx >= size) | |
517 | goto backout; | |
518 | ||
519 | ret = VM_FAULT_MINOR; | |
86e5216f | 520 | if (!pte_none(*ptep)) |
4c887265 AL |
521 | goto backout; |
522 | ||
1e8f889b DG |
523 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
524 | && (vma->vm_flags & VM_SHARED))); | |
525 | set_huge_pte_at(mm, address, ptep, new_pte); | |
526 | ||
527 | if (write_access && !(vma->vm_flags & VM_SHARED)) { | |
528 | /* Optimization, do the COW without a second fault */ | |
529 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte); | |
530 | } | |
531 | ||
ac9b9c66 | 532 | spin_unlock(&mm->page_table_lock); |
4c887265 AL |
533 | unlock_page(page); |
534 | out: | |
ac9b9c66 | 535 | return ret; |
4c887265 AL |
536 | |
537 | backout: | |
538 | spin_unlock(&mm->page_table_lock); | |
539 | hugetlb_put_quota(mapping); | |
540 | unlock_page(page); | |
541 | put_page(page); | |
542 | goto out; | |
ac9b9c66 HD |
543 | } |
544 | ||
86e5216f AL |
545 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
546 | unsigned long address, int write_access) | |
547 | { | |
548 | pte_t *ptep; | |
549 | pte_t entry; | |
1e8f889b | 550 | int ret; |
3935baa9 | 551 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
86e5216f AL |
552 | |
553 | ptep = huge_pte_alloc(mm, address); | |
554 | if (!ptep) | |
555 | return VM_FAULT_OOM; | |
556 | ||
3935baa9 DG |
557 | /* |
558 | * Serialize hugepage allocation and instantiation, so that we don't | |
559 | * get spurious allocation failures if two CPUs race to instantiate | |
560 | * the same page in the page cache. | |
561 | */ | |
562 | mutex_lock(&hugetlb_instantiation_mutex); | |
86e5216f | 563 | entry = *ptep; |
3935baa9 DG |
564 | if (pte_none(entry)) { |
565 | ret = hugetlb_no_page(mm, vma, address, ptep, write_access); | |
566 | mutex_unlock(&hugetlb_instantiation_mutex); | |
567 | return ret; | |
568 | } | |
86e5216f | 569 | |
1e8f889b DG |
570 | ret = VM_FAULT_MINOR; |
571 | ||
572 | spin_lock(&mm->page_table_lock); | |
573 | /* Check for a racing update before calling hugetlb_cow */ | |
574 | if (likely(pte_same(entry, *ptep))) | |
575 | if (write_access && !pte_write(entry)) | |
576 | ret = hugetlb_cow(mm, vma, address, ptep, entry); | |
577 | spin_unlock(&mm->page_table_lock); | |
3935baa9 | 578 | mutex_unlock(&hugetlb_instantiation_mutex); |
1e8f889b DG |
579 | |
580 | return ret; | |
86e5216f AL |
581 | } |
582 | ||
63551ae0 DG |
583 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
584 | struct page **pages, struct vm_area_struct **vmas, | |
585 | unsigned long *position, int *length, int i) | |
586 | { | |
d5d4b0aa CK |
587 | unsigned long pfn_offset; |
588 | unsigned long vaddr = *position; | |
63551ae0 DG |
589 | int remainder = *length; |
590 | ||
1c59827d | 591 | spin_lock(&mm->page_table_lock); |
63551ae0 | 592 | while (vaddr < vma->vm_end && remainder) { |
4c887265 AL |
593 | pte_t *pte; |
594 | struct page *page; | |
63551ae0 | 595 | |
4c887265 AL |
596 | /* |
597 | * Some archs (sparc64, sh*) have multiple pte_ts to | |
598 | * each hugepage. We have to make * sure we get the | |
599 | * first, for the page indexing below to work. | |
600 | */ | |
601 | pte = huge_pte_offset(mm, vaddr & HPAGE_MASK); | |
63551ae0 | 602 | |
4c887265 AL |
603 | if (!pte || pte_none(*pte)) { |
604 | int ret; | |
63551ae0 | 605 | |
4c887265 AL |
606 | spin_unlock(&mm->page_table_lock); |
607 | ret = hugetlb_fault(mm, vma, vaddr, 0); | |
608 | spin_lock(&mm->page_table_lock); | |
609 | if (ret == VM_FAULT_MINOR) | |
610 | continue; | |
63551ae0 | 611 | |
4c887265 AL |
612 | remainder = 0; |
613 | if (!i) | |
614 | i = -EFAULT; | |
615 | break; | |
616 | } | |
617 | ||
d5d4b0aa CK |
618 | pfn_offset = (vaddr & ~HPAGE_MASK) >> PAGE_SHIFT; |
619 | page = pte_page(*pte); | |
620 | same_page: | |
d6692183 CK |
621 | if (pages) { |
622 | get_page(page); | |
d5d4b0aa | 623 | pages[i] = page + pfn_offset; |
d6692183 | 624 | } |
63551ae0 DG |
625 | |
626 | if (vmas) | |
627 | vmas[i] = vma; | |
628 | ||
629 | vaddr += PAGE_SIZE; | |
d5d4b0aa | 630 | ++pfn_offset; |
63551ae0 DG |
631 | --remainder; |
632 | ++i; | |
d5d4b0aa CK |
633 | if (vaddr < vma->vm_end && remainder && |
634 | pfn_offset < HPAGE_SIZE/PAGE_SIZE) { | |
635 | /* | |
636 | * We use pfn_offset to avoid touching the pageframes | |
637 | * of this compound page. | |
638 | */ | |
639 | goto same_page; | |
640 | } | |
63551ae0 | 641 | } |
1c59827d | 642 | spin_unlock(&mm->page_table_lock); |
63551ae0 DG |
643 | *length = remainder; |
644 | *position = vaddr; | |
645 | ||
646 | return i; | |
647 | } | |
8f860591 ZY |
648 | |
649 | void hugetlb_change_protection(struct vm_area_struct *vma, | |
650 | unsigned long address, unsigned long end, pgprot_t newprot) | |
651 | { | |
652 | struct mm_struct *mm = vma->vm_mm; | |
653 | unsigned long start = address; | |
654 | pte_t *ptep; | |
655 | pte_t pte; | |
656 | ||
657 | BUG_ON(address >= end); | |
658 | flush_cache_range(vma, address, end); | |
659 | ||
39dde65c | 660 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
661 | spin_lock(&mm->page_table_lock); |
662 | for (; address < end; address += HPAGE_SIZE) { | |
663 | ptep = huge_pte_offset(mm, address); | |
664 | if (!ptep) | |
665 | continue; | |
39dde65c CK |
666 | if (huge_pmd_unshare(mm, &address, ptep)) |
667 | continue; | |
8f860591 ZY |
668 | if (!pte_none(*ptep)) { |
669 | pte = huge_ptep_get_and_clear(mm, address, ptep); | |
670 | pte = pte_mkhuge(pte_modify(pte, newprot)); | |
671 | set_huge_pte_at(mm, address, ptep, pte); | |
672 | lazy_mmu_prot_update(pte); | |
673 | } | |
674 | } | |
675 | spin_unlock(&mm->page_table_lock); | |
39dde65c | 676 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
677 | |
678 | flush_tlb_range(vma, start, end); | |
679 | } | |
680 | ||
a43a8c39 CK |
681 | struct file_region { |
682 | struct list_head link; | |
683 | long from; | |
684 | long to; | |
685 | }; | |
686 | ||
687 | static long region_add(struct list_head *head, long f, long t) | |
688 | { | |
689 | struct file_region *rg, *nrg, *trg; | |
690 | ||
691 | /* Locate the region we are either in or before. */ | |
692 | list_for_each_entry(rg, head, link) | |
693 | if (f <= rg->to) | |
694 | break; | |
695 | ||
696 | /* Round our left edge to the current segment if it encloses us. */ | |
697 | if (f > rg->from) | |
698 | f = rg->from; | |
699 | ||
700 | /* Check for and consume any regions we now overlap with. */ | |
701 | nrg = rg; | |
702 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
703 | if (&rg->link == head) | |
704 | break; | |
705 | if (rg->from > t) | |
706 | break; | |
707 | ||
708 | /* If this area reaches higher then extend our area to | |
709 | * include it completely. If this is not the first area | |
710 | * which we intend to reuse, free it. */ | |
711 | if (rg->to > t) | |
712 | t = rg->to; | |
713 | if (rg != nrg) { | |
714 | list_del(&rg->link); | |
715 | kfree(rg); | |
716 | } | |
717 | } | |
718 | nrg->from = f; | |
719 | nrg->to = t; | |
720 | return 0; | |
721 | } | |
722 | ||
723 | static long region_chg(struct list_head *head, long f, long t) | |
724 | { | |
725 | struct file_region *rg, *nrg; | |
726 | long chg = 0; | |
727 | ||
728 | /* Locate the region we are before or in. */ | |
729 | list_for_each_entry(rg, head, link) | |
730 | if (f <= rg->to) | |
731 | break; | |
732 | ||
733 | /* If we are below the current region then a new region is required. | |
734 | * Subtle, allocate a new region at the position but make it zero | |
735 | * size such that we can guarentee to record the reservation. */ | |
736 | if (&rg->link == head || t < rg->from) { | |
737 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); | |
738 | if (nrg == 0) | |
739 | return -ENOMEM; | |
740 | nrg->from = f; | |
741 | nrg->to = f; | |
742 | INIT_LIST_HEAD(&nrg->link); | |
743 | list_add(&nrg->link, rg->link.prev); | |
744 | ||
745 | return t - f; | |
746 | } | |
747 | ||
748 | /* Round our left edge to the current segment if it encloses us. */ | |
749 | if (f > rg->from) | |
750 | f = rg->from; | |
751 | chg = t - f; | |
752 | ||
753 | /* Check for and consume any regions we now overlap with. */ | |
754 | list_for_each_entry(rg, rg->link.prev, link) { | |
755 | if (&rg->link == head) | |
756 | break; | |
757 | if (rg->from > t) | |
758 | return chg; | |
759 | ||
760 | /* We overlap with this area, if it extends futher than | |
761 | * us then we must extend ourselves. Account for its | |
762 | * existing reservation. */ | |
763 | if (rg->to > t) { | |
764 | chg += rg->to - t; | |
765 | t = rg->to; | |
766 | } | |
767 | chg -= rg->to - rg->from; | |
768 | } | |
769 | return chg; | |
770 | } | |
771 | ||
772 | static long region_truncate(struct list_head *head, long end) | |
773 | { | |
774 | struct file_region *rg, *trg; | |
775 | long chg = 0; | |
776 | ||
777 | /* Locate the region we are either in or before. */ | |
778 | list_for_each_entry(rg, head, link) | |
779 | if (end <= rg->to) | |
780 | break; | |
781 | if (&rg->link == head) | |
782 | return 0; | |
783 | ||
784 | /* If we are in the middle of a region then adjust it. */ | |
785 | if (end > rg->from) { | |
786 | chg = rg->to - end; | |
787 | rg->to = end; | |
788 | rg = list_entry(rg->link.next, typeof(*rg), link); | |
789 | } | |
790 | ||
791 | /* Drop any remaining regions. */ | |
792 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
793 | if (&rg->link == head) | |
794 | break; | |
795 | chg += rg->to - rg->from; | |
796 | list_del(&rg->link); | |
797 | kfree(rg); | |
798 | } | |
799 | return chg; | |
800 | } | |
801 | ||
802 | static int hugetlb_acct_memory(long delta) | |
803 | { | |
804 | int ret = -ENOMEM; | |
805 | ||
806 | spin_lock(&hugetlb_lock); | |
807 | if ((delta + resv_huge_pages) <= free_huge_pages) { | |
808 | resv_huge_pages += delta; | |
809 | ret = 0; | |
810 | } | |
811 | spin_unlock(&hugetlb_lock); | |
812 | return ret; | |
813 | } | |
814 | ||
815 | int hugetlb_reserve_pages(struct inode *inode, long from, long to) | |
816 | { | |
817 | long ret, chg; | |
818 | ||
819 | chg = region_chg(&inode->i_mapping->private_list, from, to); | |
820 | if (chg < 0) | |
821 | return chg; | |
822 | ret = hugetlb_acct_memory(chg); | |
823 | if (ret < 0) | |
824 | return ret; | |
825 | region_add(&inode->i_mapping->private_list, from, to); | |
826 | return 0; | |
827 | } | |
828 | ||
829 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) | |
830 | { | |
831 | long chg = region_truncate(&inode->i_mapping->private_list, offset); | |
832 | hugetlb_acct_memory(freed - chg); | |
833 | } |