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; | |
b45b5bd6 | 25 | static unsigned long nr_huge_pages, free_huge_pages, reserved_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, | |
47 | unsigned long addr) | |
48 | { | |
49 | int i; | |
50 | ||
51 | might_sleep(); | |
52 | for (i = 0; i < HPAGE_SIZE/PAGE_SIZE; i++) { | |
53 | cond_resched(); | |
54 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE); | |
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 CL |
74 | for (z = zonelist->zones; *z; z++) { |
75 | nid = (*z)->zone_pgdat->node_id; | |
aea47ff3 CL |
76 | if (cpuset_zone_allowed(*z, GFP_HIGHUSER) && |
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) { |
a482289d | 112 | page[1].lru.next = (void *)free_huge_page; /* dtor */ |
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 | 125 | { |
b45b5bd6 | 126 | struct inode *inode = vma->vm_file->f_dentry->d_inode; |
1da177e4 | 127 | struct page *page; |
b45b5bd6 DG |
128 | int use_reserve = 0; |
129 | unsigned long idx; | |
1da177e4 LT |
130 | |
131 | spin_lock(&hugetlb_lock); | |
b45b5bd6 DG |
132 | |
133 | if (vma->vm_flags & VM_MAYSHARE) { | |
134 | ||
135 | /* idx = radix tree index, i.e. offset into file in | |
136 | * HPAGE_SIZE units */ | |
137 | idx = ((addr - vma->vm_start) >> HPAGE_SHIFT) | |
138 | + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); | |
139 | ||
140 | /* The hugetlbfs specific inode info stores the number | |
141 | * of "guaranteed available" (huge) pages. That is, | |
142 | * the first 'prereserved_hpages' pages of the inode | |
143 | * are either already instantiated, or have been | |
144 | * pre-reserved (by hugetlb_reserve_for_inode()). Here | |
145 | * we're in the process of instantiating the page, so | |
146 | * we use this to determine whether to draw from the | |
147 | * pre-reserved pool or the truly free pool. */ | |
148 | if (idx < HUGETLBFS_I(inode)->prereserved_hpages) | |
149 | use_reserve = 1; | |
1da177e4 | 150 | } |
b45b5bd6 DG |
151 | |
152 | if (!use_reserve) { | |
153 | if (free_huge_pages <= reserved_huge_pages) | |
154 | goto fail; | |
155 | } else { | |
156 | BUG_ON(reserved_huge_pages == 0); | |
157 | reserved_huge_pages--; | |
158 | } | |
159 | ||
160 | page = dequeue_huge_page(vma, addr); | |
161 | if (!page) | |
162 | goto fail; | |
163 | ||
1da177e4 | 164 | spin_unlock(&hugetlb_lock); |
7835e98b | 165 | set_page_refcounted(page); |
1da177e4 | 166 | return page; |
b45b5bd6 DG |
167 | |
168 | fail: | |
169 | WARN_ON(use_reserve); /* reserved allocations shouldn't fail */ | |
170 | spin_unlock(&hugetlb_lock); | |
171 | return NULL; | |
172 | } | |
173 | ||
174 | /* hugetlb_extend_reservation() | |
175 | * | |
176 | * Ensure that at least 'atleast' hugepages are, and will remain, | |
177 | * available to instantiate the first 'atleast' pages of the given | |
178 | * inode. If the inode doesn't already have this many pages reserved | |
179 | * or instantiated, set aside some hugepages in the reserved pool to | |
180 | * satisfy later faults (or fail now if there aren't enough, rather | |
181 | * than getting the SIGBUS later). | |
182 | */ | |
183 | int hugetlb_extend_reservation(struct hugetlbfs_inode_info *info, | |
184 | unsigned long atleast) | |
185 | { | |
186 | struct inode *inode = &info->vfs_inode; | |
187 | unsigned long change_in_reserve = 0; | |
188 | int ret = 0; | |
189 | ||
190 | spin_lock(&hugetlb_lock); | |
191 | read_lock_irq(&inode->i_mapping->tree_lock); | |
192 | ||
193 | if (info->prereserved_hpages >= atleast) | |
194 | goto out; | |
195 | ||
196 | /* Because we always call this on shared mappings, none of the | |
197 | * pages beyond info->prereserved_hpages can have been | |
198 | * instantiated, so we need to reserve all of them now. */ | |
199 | change_in_reserve = atleast - info->prereserved_hpages; | |
200 | ||
201 | if ((reserved_huge_pages + change_in_reserve) > free_huge_pages) { | |
202 | ret = -ENOMEM; | |
203 | goto out; | |
204 | } | |
205 | ||
206 | reserved_huge_pages += change_in_reserve; | |
207 | info->prereserved_hpages = atleast; | |
208 | ||
209 | out: | |
210 | read_unlock_irq(&inode->i_mapping->tree_lock); | |
211 | spin_unlock(&hugetlb_lock); | |
212 | ||
213 | return ret; | |
214 | } | |
215 | ||
216 | /* hugetlb_truncate_reservation() | |
217 | * | |
218 | * This returns pages reserved for the given inode to the general free | |
219 | * hugepage pool. If the inode has any pages prereserved, but not | |
220 | * instantiated, beyond offset (atmost << HPAGE_SIZE), then release | |
221 | * them. | |
222 | */ | |
223 | void hugetlb_truncate_reservation(struct hugetlbfs_inode_info *info, | |
224 | unsigned long atmost) | |
225 | { | |
226 | struct inode *inode = &info->vfs_inode; | |
227 | struct address_space *mapping = inode->i_mapping; | |
228 | unsigned long idx; | |
229 | unsigned long change_in_reserve = 0; | |
230 | struct page *page; | |
231 | ||
232 | spin_lock(&hugetlb_lock); | |
233 | read_lock_irq(&inode->i_mapping->tree_lock); | |
234 | ||
235 | if (info->prereserved_hpages <= atmost) | |
236 | goto out; | |
237 | ||
238 | /* Count pages which were reserved, but not instantiated, and | |
239 | * which we can now release. */ | |
240 | for (idx = atmost; idx < info->prereserved_hpages; idx++) { | |
241 | page = radix_tree_lookup(&mapping->page_tree, idx); | |
242 | if (!page) | |
243 | /* Pages which are already instantiated can't | |
244 | * be unreserved (and in fact have already | |
245 | * been removed from the reserved pool) */ | |
246 | change_in_reserve++; | |
247 | } | |
248 | ||
249 | BUG_ON(reserved_huge_pages < change_in_reserve); | |
250 | reserved_huge_pages -= change_in_reserve; | |
251 | info->prereserved_hpages = atmost; | |
252 | ||
253 | out: | |
254 | read_unlock_irq(&inode->i_mapping->tree_lock); | |
255 | spin_unlock(&hugetlb_lock); | |
1da177e4 LT |
256 | } |
257 | ||
258 | static int __init hugetlb_init(void) | |
259 | { | |
260 | unsigned long i; | |
1da177e4 | 261 | |
3c726f8d BH |
262 | if (HPAGE_SHIFT == 0) |
263 | return 0; | |
264 | ||
1da177e4 LT |
265 | for (i = 0; i < MAX_NUMNODES; ++i) |
266 | INIT_LIST_HEAD(&hugepage_freelists[i]); | |
267 | ||
268 | for (i = 0; i < max_huge_pages; ++i) { | |
a482289d | 269 | if (!alloc_fresh_huge_page()) |
1da177e4 | 270 | break; |
1da177e4 LT |
271 | } |
272 | max_huge_pages = free_huge_pages = nr_huge_pages = i; | |
273 | printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages); | |
274 | return 0; | |
275 | } | |
276 | module_init(hugetlb_init); | |
277 | ||
278 | static int __init hugetlb_setup(char *s) | |
279 | { | |
280 | if (sscanf(s, "%lu", &max_huge_pages) <= 0) | |
281 | max_huge_pages = 0; | |
282 | return 1; | |
283 | } | |
284 | __setup("hugepages=", hugetlb_setup); | |
285 | ||
286 | #ifdef CONFIG_SYSCTL | |
287 | static void update_and_free_page(struct page *page) | |
288 | { | |
289 | int i; | |
290 | nr_huge_pages--; | |
291 | nr_huge_pages_node[page_zone(page)->zone_pgdat->node_id]--; | |
292 | for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) { | |
293 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | | |
294 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | | |
295 | 1 << PG_private | 1<< PG_writeback); | |
1da177e4 | 296 | } |
a482289d | 297 | page[1].lru.next = NULL; |
7835e98b | 298 | set_page_refcounted(page); |
1da177e4 LT |
299 | __free_pages(page, HUGETLB_PAGE_ORDER); |
300 | } | |
301 | ||
302 | #ifdef CONFIG_HIGHMEM | |
303 | static void try_to_free_low(unsigned long count) | |
304 | { | |
305 | int i, nid; | |
306 | for (i = 0; i < MAX_NUMNODES; ++i) { | |
307 | struct page *page, *next; | |
308 | list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) { | |
309 | if (PageHighMem(page)) | |
310 | continue; | |
311 | list_del(&page->lru); | |
312 | update_and_free_page(page); | |
313 | nid = page_zone(page)->zone_pgdat->node_id; | |
314 | free_huge_pages--; | |
315 | free_huge_pages_node[nid]--; | |
316 | if (count >= nr_huge_pages) | |
317 | return; | |
318 | } | |
319 | } | |
320 | } | |
321 | #else | |
322 | static inline void try_to_free_low(unsigned long count) | |
323 | { | |
324 | } | |
325 | #endif | |
326 | ||
327 | static unsigned long set_max_huge_pages(unsigned long count) | |
328 | { | |
329 | while (count > nr_huge_pages) { | |
a482289d | 330 | if (!alloc_fresh_huge_page()) |
1da177e4 | 331 | return nr_huge_pages; |
1da177e4 LT |
332 | } |
333 | if (count >= nr_huge_pages) | |
334 | return nr_huge_pages; | |
335 | ||
336 | spin_lock(&hugetlb_lock); | |
78c997a4 | 337 | count = max(count, reserved_huge_pages); |
1da177e4 LT |
338 | try_to_free_low(count); |
339 | while (count < nr_huge_pages) { | |
5da7ca86 | 340 | struct page *page = dequeue_huge_page(NULL, 0); |
1da177e4 LT |
341 | if (!page) |
342 | break; | |
343 | update_and_free_page(page); | |
344 | } | |
345 | spin_unlock(&hugetlb_lock); | |
346 | return nr_huge_pages; | |
347 | } | |
348 | ||
349 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, | |
350 | struct file *file, void __user *buffer, | |
351 | size_t *length, loff_t *ppos) | |
352 | { | |
353 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); | |
354 | max_huge_pages = set_max_huge_pages(max_huge_pages); | |
355 | return 0; | |
356 | } | |
357 | #endif /* CONFIG_SYSCTL */ | |
358 | ||
359 | int hugetlb_report_meminfo(char *buf) | |
360 | { | |
361 | return sprintf(buf, | |
362 | "HugePages_Total: %5lu\n" | |
363 | "HugePages_Free: %5lu\n" | |
b45b5bd6 | 364 | "HugePages_Rsvd: %5lu\n" |
1da177e4 LT |
365 | "Hugepagesize: %5lu kB\n", |
366 | nr_huge_pages, | |
367 | free_huge_pages, | |
b45b5bd6 | 368 | reserved_huge_pages, |
1da177e4 LT |
369 | HPAGE_SIZE/1024); |
370 | } | |
371 | ||
372 | int hugetlb_report_node_meminfo(int nid, char *buf) | |
373 | { | |
374 | return sprintf(buf, | |
375 | "Node %d HugePages_Total: %5u\n" | |
376 | "Node %d HugePages_Free: %5u\n", | |
377 | nid, nr_huge_pages_node[nid], | |
378 | nid, free_huge_pages_node[nid]); | |
379 | } | |
380 | ||
1da177e4 LT |
381 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
382 | unsigned long hugetlb_total_pages(void) | |
383 | { | |
384 | return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE); | |
385 | } | |
1da177e4 LT |
386 | |
387 | /* | |
388 | * We cannot handle pagefaults against hugetlb pages at all. They cause | |
389 | * handle_mm_fault() to try to instantiate regular-sized pages in the | |
390 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get | |
391 | * this far. | |
392 | */ | |
393 | static struct page *hugetlb_nopage(struct vm_area_struct *vma, | |
394 | unsigned long address, int *unused) | |
395 | { | |
396 | BUG(); | |
397 | return NULL; | |
398 | } | |
399 | ||
400 | struct vm_operations_struct hugetlb_vm_ops = { | |
401 | .nopage = hugetlb_nopage, | |
402 | }; | |
403 | ||
1e8f889b DG |
404 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
405 | int writable) | |
63551ae0 DG |
406 | { |
407 | pte_t entry; | |
408 | ||
1e8f889b | 409 | if (writable) { |
63551ae0 DG |
410 | entry = |
411 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); | |
412 | } else { | |
413 | entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot)); | |
414 | } | |
415 | entry = pte_mkyoung(entry); | |
416 | entry = pte_mkhuge(entry); | |
417 | ||
418 | return entry; | |
419 | } | |
420 | ||
1e8f889b DG |
421 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
422 | unsigned long address, pte_t *ptep) | |
423 | { | |
424 | pte_t entry; | |
425 | ||
426 | entry = pte_mkwrite(pte_mkdirty(*ptep)); | |
427 | ptep_set_access_flags(vma, address, ptep, entry, 1); | |
428 | update_mmu_cache(vma, address, entry); | |
429 | lazy_mmu_prot_update(entry); | |
430 | } | |
431 | ||
432 | ||
63551ae0 DG |
433 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
434 | struct vm_area_struct *vma) | |
435 | { | |
436 | pte_t *src_pte, *dst_pte, entry; | |
437 | struct page *ptepage; | |
1c59827d | 438 | unsigned long addr; |
1e8f889b DG |
439 | int cow; |
440 | ||
441 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; | |
63551ae0 | 442 | |
1c59827d | 443 | for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) { |
c74df32c HD |
444 | src_pte = huge_pte_offset(src, addr); |
445 | if (!src_pte) | |
446 | continue; | |
63551ae0 DG |
447 | dst_pte = huge_pte_alloc(dst, addr); |
448 | if (!dst_pte) | |
449 | goto nomem; | |
c74df32c | 450 | spin_lock(&dst->page_table_lock); |
1c59827d | 451 | spin_lock(&src->page_table_lock); |
c74df32c | 452 | if (!pte_none(*src_pte)) { |
1e8f889b DG |
453 | if (cow) |
454 | ptep_set_wrprotect(src, addr, src_pte); | |
1c59827d HD |
455 | entry = *src_pte; |
456 | ptepage = pte_page(entry); | |
457 | get_page(ptepage); | |
4294621f | 458 | add_mm_counter(dst, file_rss, HPAGE_SIZE / PAGE_SIZE); |
1c59827d HD |
459 | set_huge_pte_at(dst, addr, dst_pte, entry); |
460 | } | |
461 | spin_unlock(&src->page_table_lock); | |
c74df32c | 462 | spin_unlock(&dst->page_table_lock); |
63551ae0 DG |
463 | } |
464 | return 0; | |
465 | ||
466 | nomem: | |
467 | return -ENOMEM; | |
468 | } | |
469 | ||
470 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, | |
471 | unsigned long end) | |
472 | { | |
473 | struct mm_struct *mm = vma->vm_mm; | |
474 | unsigned long address; | |
c7546f8f | 475 | pte_t *ptep; |
63551ae0 DG |
476 | pte_t pte; |
477 | struct page *page; | |
478 | ||
479 | WARN_ON(!is_vm_hugetlb_page(vma)); | |
480 | BUG_ON(start & ~HPAGE_MASK); | |
481 | BUG_ON(end & ~HPAGE_MASK); | |
482 | ||
508034a3 HD |
483 | spin_lock(&mm->page_table_lock); |
484 | ||
365e9c87 HD |
485 | /* Update high watermark before we lower rss */ |
486 | update_hiwater_rss(mm); | |
487 | ||
63551ae0 | 488 | for (address = start; address < end; address += HPAGE_SIZE) { |
c7546f8f | 489 | ptep = huge_pte_offset(mm, address); |
4c887265 | 490 | if (!ptep) |
c7546f8f DG |
491 | continue; |
492 | ||
493 | pte = huge_ptep_get_and_clear(mm, address, ptep); | |
63551ae0 DG |
494 | if (pte_none(pte)) |
495 | continue; | |
c7546f8f | 496 | |
63551ae0 DG |
497 | page = pte_page(pte); |
498 | put_page(page); | |
4294621f | 499 | add_mm_counter(mm, file_rss, (int) -(HPAGE_SIZE / PAGE_SIZE)); |
63551ae0 | 500 | } |
63551ae0 | 501 | |
1da177e4 | 502 | spin_unlock(&mm->page_table_lock); |
508034a3 | 503 | flush_tlb_range(vma, start, end); |
1da177e4 | 504 | } |
63551ae0 | 505 | |
1e8f889b DG |
506 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
507 | unsigned long address, pte_t *ptep, pte_t pte) | |
508 | { | |
509 | struct page *old_page, *new_page; | |
79ac6ba4 | 510 | int avoidcopy; |
1e8f889b DG |
511 | |
512 | old_page = pte_page(pte); | |
513 | ||
514 | /* If no-one else is actually using this page, avoid the copy | |
515 | * and just make the page writable */ | |
516 | avoidcopy = (page_count(old_page) == 1); | |
517 | if (avoidcopy) { | |
518 | set_huge_ptep_writable(vma, address, ptep); | |
519 | return VM_FAULT_MINOR; | |
520 | } | |
521 | ||
522 | page_cache_get(old_page); | |
5da7ca86 | 523 | new_page = alloc_huge_page(vma, address); |
1e8f889b DG |
524 | |
525 | if (!new_page) { | |
526 | page_cache_release(old_page); | |
0df420d8 | 527 | return VM_FAULT_OOM; |
1e8f889b DG |
528 | } |
529 | ||
530 | spin_unlock(&mm->page_table_lock); | |
79ac6ba4 | 531 | copy_huge_page(new_page, old_page, address); |
1e8f889b DG |
532 | spin_lock(&mm->page_table_lock); |
533 | ||
534 | ptep = huge_pte_offset(mm, address & HPAGE_MASK); | |
535 | if (likely(pte_same(*ptep, pte))) { | |
536 | /* Break COW */ | |
537 | set_huge_pte_at(mm, address, ptep, | |
538 | make_huge_pte(vma, new_page, 1)); | |
539 | /* Make the old page be freed below */ | |
540 | new_page = old_page; | |
541 | } | |
542 | page_cache_release(new_page); | |
543 | page_cache_release(old_page); | |
544 | return VM_FAULT_MINOR; | |
545 | } | |
546 | ||
86e5216f | 547 | int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1e8f889b | 548 | unsigned long address, pte_t *ptep, int write_access) |
ac9b9c66 HD |
549 | { |
550 | int ret = VM_FAULT_SIGBUS; | |
4c887265 AL |
551 | unsigned long idx; |
552 | unsigned long size; | |
4c887265 AL |
553 | struct page *page; |
554 | struct address_space *mapping; | |
1e8f889b | 555 | pte_t new_pte; |
4c887265 | 556 | |
4c887265 AL |
557 | mapping = vma->vm_file->f_mapping; |
558 | idx = ((address - vma->vm_start) >> HPAGE_SHIFT) | |
559 | + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); | |
560 | ||
561 | /* | |
562 | * Use page lock to guard against racing truncation | |
563 | * before we get page_table_lock. | |
564 | */ | |
6bda666a CL |
565 | retry: |
566 | page = find_lock_page(mapping, idx); | |
567 | if (!page) { | |
568 | if (hugetlb_get_quota(mapping)) | |
569 | goto out; | |
570 | page = alloc_huge_page(vma, address); | |
571 | if (!page) { | |
572 | hugetlb_put_quota(mapping); | |
0df420d8 | 573 | ret = VM_FAULT_OOM; |
6bda666a CL |
574 | goto out; |
575 | } | |
79ac6ba4 | 576 | clear_huge_page(page, address); |
ac9b9c66 | 577 | |
6bda666a CL |
578 | if (vma->vm_flags & VM_SHARED) { |
579 | int err; | |
580 | ||
581 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); | |
582 | if (err) { | |
583 | put_page(page); | |
584 | hugetlb_put_quota(mapping); | |
585 | if (err == -EEXIST) | |
586 | goto retry; | |
587 | goto out; | |
588 | } | |
589 | } else | |
590 | lock_page(page); | |
591 | } | |
1e8f889b | 592 | |
ac9b9c66 | 593 | spin_lock(&mm->page_table_lock); |
4c887265 AL |
594 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
595 | if (idx >= size) | |
596 | goto backout; | |
597 | ||
598 | ret = VM_FAULT_MINOR; | |
86e5216f | 599 | if (!pte_none(*ptep)) |
4c887265 AL |
600 | goto backout; |
601 | ||
602 | add_mm_counter(mm, file_rss, HPAGE_SIZE / PAGE_SIZE); | |
1e8f889b DG |
603 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
604 | && (vma->vm_flags & VM_SHARED))); | |
605 | set_huge_pte_at(mm, address, ptep, new_pte); | |
606 | ||
607 | if (write_access && !(vma->vm_flags & VM_SHARED)) { | |
608 | /* Optimization, do the COW without a second fault */ | |
609 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte); | |
610 | } | |
611 | ||
ac9b9c66 | 612 | spin_unlock(&mm->page_table_lock); |
4c887265 AL |
613 | unlock_page(page); |
614 | out: | |
ac9b9c66 | 615 | return ret; |
4c887265 AL |
616 | |
617 | backout: | |
618 | spin_unlock(&mm->page_table_lock); | |
619 | hugetlb_put_quota(mapping); | |
620 | unlock_page(page); | |
621 | put_page(page); | |
622 | goto out; | |
ac9b9c66 HD |
623 | } |
624 | ||
86e5216f AL |
625 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
626 | unsigned long address, int write_access) | |
627 | { | |
628 | pte_t *ptep; | |
629 | pte_t entry; | |
1e8f889b | 630 | int ret; |
3935baa9 | 631 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
86e5216f AL |
632 | |
633 | ptep = huge_pte_alloc(mm, address); | |
634 | if (!ptep) | |
635 | return VM_FAULT_OOM; | |
636 | ||
3935baa9 DG |
637 | /* |
638 | * Serialize hugepage allocation and instantiation, so that we don't | |
639 | * get spurious allocation failures if two CPUs race to instantiate | |
640 | * the same page in the page cache. | |
641 | */ | |
642 | mutex_lock(&hugetlb_instantiation_mutex); | |
86e5216f | 643 | entry = *ptep; |
3935baa9 DG |
644 | if (pte_none(entry)) { |
645 | ret = hugetlb_no_page(mm, vma, address, ptep, write_access); | |
646 | mutex_unlock(&hugetlb_instantiation_mutex); | |
647 | return ret; | |
648 | } | |
86e5216f | 649 | |
1e8f889b DG |
650 | ret = VM_FAULT_MINOR; |
651 | ||
652 | spin_lock(&mm->page_table_lock); | |
653 | /* Check for a racing update before calling hugetlb_cow */ | |
654 | if (likely(pte_same(entry, *ptep))) | |
655 | if (write_access && !pte_write(entry)) | |
656 | ret = hugetlb_cow(mm, vma, address, ptep, entry); | |
657 | spin_unlock(&mm->page_table_lock); | |
3935baa9 | 658 | mutex_unlock(&hugetlb_instantiation_mutex); |
1e8f889b DG |
659 | |
660 | return ret; | |
86e5216f AL |
661 | } |
662 | ||
63551ae0 DG |
663 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
664 | struct page **pages, struct vm_area_struct **vmas, | |
665 | unsigned long *position, int *length, int i) | |
666 | { | |
d5d4b0aa CK |
667 | unsigned long pfn_offset; |
668 | unsigned long vaddr = *position; | |
63551ae0 DG |
669 | int remainder = *length; |
670 | ||
1c59827d | 671 | spin_lock(&mm->page_table_lock); |
63551ae0 | 672 | while (vaddr < vma->vm_end && remainder) { |
4c887265 AL |
673 | pte_t *pte; |
674 | struct page *page; | |
63551ae0 | 675 | |
4c887265 AL |
676 | /* |
677 | * Some archs (sparc64, sh*) have multiple pte_ts to | |
678 | * each hugepage. We have to make * sure we get the | |
679 | * first, for the page indexing below to work. | |
680 | */ | |
681 | pte = huge_pte_offset(mm, vaddr & HPAGE_MASK); | |
63551ae0 | 682 | |
4c887265 AL |
683 | if (!pte || pte_none(*pte)) { |
684 | int ret; | |
63551ae0 | 685 | |
4c887265 AL |
686 | spin_unlock(&mm->page_table_lock); |
687 | ret = hugetlb_fault(mm, vma, vaddr, 0); | |
688 | spin_lock(&mm->page_table_lock); | |
689 | if (ret == VM_FAULT_MINOR) | |
690 | continue; | |
63551ae0 | 691 | |
4c887265 AL |
692 | remainder = 0; |
693 | if (!i) | |
694 | i = -EFAULT; | |
695 | break; | |
696 | } | |
697 | ||
d5d4b0aa CK |
698 | pfn_offset = (vaddr & ~HPAGE_MASK) >> PAGE_SHIFT; |
699 | page = pte_page(*pte); | |
700 | same_page: | |
d6692183 CK |
701 | if (pages) { |
702 | get_page(page); | |
d5d4b0aa | 703 | pages[i] = page + pfn_offset; |
d6692183 | 704 | } |
63551ae0 DG |
705 | |
706 | if (vmas) | |
707 | vmas[i] = vma; | |
708 | ||
709 | vaddr += PAGE_SIZE; | |
d5d4b0aa | 710 | ++pfn_offset; |
63551ae0 DG |
711 | --remainder; |
712 | ++i; | |
d5d4b0aa CK |
713 | if (vaddr < vma->vm_end && remainder && |
714 | pfn_offset < HPAGE_SIZE/PAGE_SIZE) { | |
715 | /* | |
716 | * We use pfn_offset to avoid touching the pageframes | |
717 | * of this compound page. | |
718 | */ | |
719 | goto same_page; | |
720 | } | |
63551ae0 | 721 | } |
1c59827d | 722 | spin_unlock(&mm->page_table_lock); |
63551ae0 DG |
723 | *length = remainder; |
724 | *position = vaddr; | |
725 | ||
726 | return i; | |
727 | } | |
8f860591 ZY |
728 | |
729 | void hugetlb_change_protection(struct vm_area_struct *vma, | |
730 | unsigned long address, unsigned long end, pgprot_t newprot) | |
731 | { | |
732 | struct mm_struct *mm = vma->vm_mm; | |
733 | unsigned long start = address; | |
734 | pte_t *ptep; | |
735 | pte_t pte; | |
736 | ||
737 | BUG_ON(address >= end); | |
738 | flush_cache_range(vma, address, end); | |
739 | ||
740 | spin_lock(&mm->page_table_lock); | |
741 | for (; address < end; address += HPAGE_SIZE) { | |
742 | ptep = huge_pte_offset(mm, address); | |
743 | if (!ptep) | |
744 | continue; | |
745 | if (!pte_none(*ptep)) { | |
746 | pte = huge_ptep_get_and_clear(mm, address, ptep); | |
747 | pte = pte_mkhuge(pte_modify(pte, newprot)); | |
748 | set_huge_pte_at(mm, address, ptep, pte); | |
749 | lazy_mmu_prot_update(pte); | |
750 | } | |
751 | } | |
752 | spin_unlock(&mm->page_table_lock); | |
753 | ||
754 | flush_tlb_range(vma, start, end); | |
755 | } | |
756 |