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 DG |
13 | #include <linux/pagemap.h> |
14 | #include <asm/page.h> | |
15 | #include <asm/pgtable.h> | |
16 | ||
17 | #include <linux/hugetlb.h> | |
1da177e4 LT |
18 | |
19 | const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; | |
20 | static unsigned long nr_huge_pages, free_huge_pages; | |
21 | unsigned long max_huge_pages; | |
22 | static struct list_head hugepage_freelists[MAX_NUMNODES]; | |
23 | static unsigned int nr_huge_pages_node[MAX_NUMNODES]; | |
24 | static unsigned int free_huge_pages_node[MAX_NUMNODES]; | |
25 | static DEFINE_SPINLOCK(hugetlb_lock); | |
26 | ||
27 | static void enqueue_huge_page(struct page *page) | |
28 | { | |
29 | int nid = page_to_nid(page); | |
30 | list_add(&page->lru, &hugepage_freelists[nid]); | |
31 | free_huge_pages++; | |
32 | free_huge_pages_node[nid]++; | |
33 | } | |
34 | ||
35 | static struct page *dequeue_huge_page(void) | |
36 | { | |
37 | int nid = numa_node_id(); | |
38 | struct page *page = NULL; | |
39 | ||
40 | if (list_empty(&hugepage_freelists[nid])) { | |
41 | for (nid = 0; nid < MAX_NUMNODES; ++nid) | |
42 | if (!list_empty(&hugepage_freelists[nid])) | |
43 | break; | |
44 | } | |
45 | if (nid >= 0 && nid < MAX_NUMNODES && | |
46 | !list_empty(&hugepage_freelists[nid])) { | |
47 | page = list_entry(hugepage_freelists[nid].next, | |
48 | struct page, lru); | |
49 | list_del(&page->lru); | |
50 | free_huge_pages--; | |
51 | free_huge_pages_node[nid]--; | |
52 | } | |
53 | return page; | |
54 | } | |
55 | ||
56 | static struct page *alloc_fresh_huge_page(void) | |
57 | { | |
58 | static int nid = 0; | |
59 | struct page *page; | |
60 | page = alloc_pages_node(nid, GFP_HIGHUSER|__GFP_COMP|__GFP_NOWARN, | |
61 | HUGETLB_PAGE_ORDER); | |
62 | nid = (nid + 1) % num_online_nodes(); | |
63 | if (page) { | |
64 | nr_huge_pages++; | |
65 | nr_huge_pages_node[page_to_nid(page)]++; | |
66 | } | |
67 | return page; | |
68 | } | |
69 | ||
70 | void free_huge_page(struct page *page) | |
71 | { | |
72 | BUG_ON(page_count(page)); | |
73 | ||
74 | INIT_LIST_HEAD(&page->lru); | |
75 | page[1].mapping = NULL; | |
76 | ||
77 | spin_lock(&hugetlb_lock); | |
78 | enqueue_huge_page(page); | |
79 | spin_unlock(&hugetlb_lock); | |
80 | } | |
81 | ||
82 | struct page *alloc_huge_page(void) | |
83 | { | |
84 | struct page *page; | |
85 | int i; | |
86 | ||
87 | spin_lock(&hugetlb_lock); | |
88 | page = dequeue_huge_page(); | |
89 | if (!page) { | |
90 | spin_unlock(&hugetlb_lock); | |
91 | return NULL; | |
92 | } | |
93 | spin_unlock(&hugetlb_lock); | |
94 | set_page_count(page, 1); | |
95 | page[1].mapping = (void *)free_huge_page; | |
96 | for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); ++i) | |
97 | clear_highpage(&page[i]); | |
98 | return page; | |
99 | } | |
100 | ||
101 | static int __init hugetlb_init(void) | |
102 | { | |
103 | unsigned long i; | |
104 | struct page *page; | |
105 | ||
106 | for (i = 0; i < MAX_NUMNODES; ++i) | |
107 | INIT_LIST_HEAD(&hugepage_freelists[i]); | |
108 | ||
109 | for (i = 0; i < max_huge_pages; ++i) { | |
110 | page = alloc_fresh_huge_page(); | |
111 | if (!page) | |
112 | break; | |
113 | spin_lock(&hugetlb_lock); | |
114 | enqueue_huge_page(page); | |
115 | spin_unlock(&hugetlb_lock); | |
116 | } | |
117 | max_huge_pages = free_huge_pages = nr_huge_pages = i; | |
118 | printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages); | |
119 | return 0; | |
120 | } | |
121 | module_init(hugetlb_init); | |
122 | ||
123 | static int __init hugetlb_setup(char *s) | |
124 | { | |
125 | if (sscanf(s, "%lu", &max_huge_pages) <= 0) | |
126 | max_huge_pages = 0; | |
127 | return 1; | |
128 | } | |
129 | __setup("hugepages=", hugetlb_setup); | |
130 | ||
131 | #ifdef CONFIG_SYSCTL | |
132 | static void update_and_free_page(struct page *page) | |
133 | { | |
134 | int i; | |
135 | nr_huge_pages--; | |
136 | nr_huge_pages_node[page_zone(page)->zone_pgdat->node_id]--; | |
137 | for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) { | |
138 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | | |
139 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | | |
140 | 1 << PG_private | 1<< PG_writeback); | |
141 | set_page_count(&page[i], 0); | |
142 | } | |
143 | set_page_count(page, 1); | |
144 | __free_pages(page, HUGETLB_PAGE_ORDER); | |
145 | } | |
146 | ||
147 | #ifdef CONFIG_HIGHMEM | |
148 | static void try_to_free_low(unsigned long count) | |
149 | { | |
150 | int i, nid; | |
151 | for (i = 0; i < MAX_NUMNODES; ++i) { | |
152 | struct page *page, *next; | |
153 | list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) { | |
154 | if (PageHighMem(page)) | |
155 | continue; | |
156 | list_del(&page->lru); | |
157 | update_and_free_page(page); | |
158 | nid = page_zone(page)->zone_pgdat->node_id; | |
159 | free_huge_pages--; | |
160 | free_huge_pages_node[nid]--; | |
161 | if (count >= nr_huge_pages) | |
162 | return; | |
163 | } | |
164 | } | |
165 | } | |
166 | #else | |
167 | static inline void try_to_free_low(unsigned long count) | |
168 | { | |
169 | } | |
170 | #endif | |
171 | ||
172 | static unsigned long set_max_huge_pages(unsigned long count) | |
173 | { | |
174 | while (count > nr_huge_pages) { | |
175 | struct page *page = alloc_fresh_huge_page(); | |
176 | if (!page) | |
177 | return nr_huge_pages; | |
178 | spin_lock(&hugetlb_lock); | |
179 | enqueue_huge_page(page); | |
180 | spin_unlock(&hugetlb_lock); | |
181 | } | |
182 | if (count >= nr_huge_pages) | |
183 | return nr_huge_pages; | |
184 | ||
185 | spin_lock(&hugetlb_lock); | |
186 | try_to_free_low(count); | |
187 | while (count < nr_huge_pages) { | |
188 | struct page *page = dequeue_huge_page(); | |
189 | if (!page) | |
190 | break; | |
191 | update_and_free_page(page); | |
192 | } | |
193 | spin_unlock(&hugetlb_lock); | |
194 | return nr_huge_pages; | |
195 | } | |
196 | ||
197 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, | |
198 | struct file *file, void __user *buffer, | |
199 | size_t *length, loff_t *ppos) | |
200 | { | |
201 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); | |
202 | max_huge_pages = set_max_huge_pages(max_huge_pages); | |
203 | return 0; | |
204 | } | |
205 | #endif /* CONFIG_SYSCTL */ | |
206 | ||
207 | int hugetlb_report_meminfo(char *buf) | |
208 | { | |
209 | return sprintf(buf, | |
210 | "HugePages_Total: %5lu\n" | |
211 | "HugePages_Free: %5lu\n" | |
212 | "Hugepagesize: %5lu kB\n", | |
213 | nr_huge_pages, | |
214 | free_huge_pages, | |
215 | HPAGE_SIZE/1024); | |
216 | } | |
217 | ||
218 | int hugetlb_report_node_meminfo(int nid, char *buf) | |
219 | { | |
220 | return sprintf(buf, | |
221 | "Node %d HugePages_Total: %5u\n" | |
222 | "Node %d HugePages_Free: %5u\n", | |
223 | nid, nr_huge_pages_node[nid], | |
224 | nid, free_huge_pages_node[nid]); | |
225 | } | |
226 | ||
227 | int is_hugepage_mem_enough(size_t size) | |
228 | { | |
229 | return (size + ~HPAGE_MASK)/HPAGE_SIZE <= free_huge_pages; | |
230 | } | |
231 | ||
232 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ | |
233 | unsigned long hugetlb_total_pages(void) | |
234 | { | |
235 | return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE); | |
236 | } | |
237 | EXPORT_SYMBOL(hugetlb_total_pages); | |
238 | ||
239 | /* | |
240 | * We cannot handle pagefaults against hugetlb pages at all. They cause | |
241 | * handle_mm_fault() to try to instantiate regular-sized pages in the | |
242 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get | |
243 | * this far. | |
244 | */ | |
245 | static struct page *hugetlb_nopage(struct vm_area_struct *vma, | |
246 | unsigned long address, int *unused) | |
247 | { | |
248 | BUG(); | |
249 | return NULL; | |
250 | } | |
251 | ||
252 | struct vm_operations_struct hugetlb_vm_ops = { | |
253 | .nopage = hugetlb_nopage, | |
254 | }; | |
255 | ||
63551ae0 DG |
256 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page) |
257 | { | |
258 | pte_t entry; | |
259 | ||
260 | if (vma->vm_flags & VM_WRITE) { | |
261 | entry = | |
262 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); | |
263 | } else { | |
264 | entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot)); | |
265 | } | |
266 | entry = pte_mkyoung(entry); | |
267 | entry = pte_mkhuge(entry); | |
268 | ||
269 | return entry; | |
270 | } | |
271 | ||
272 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, | |
273 | struct vm_area_struct *vma) | |
274 | { | |
275 | pte_t *src_pte, *dst_pte, entry; | |
276 | struct page *ptepage; | |
1c59827d | 277 | unsigned long addr; |
63551ae0 | 278 | |
1c59827d | 279 | for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) { |
c74df32c HD |
280 | src_pte = huge_pte_offset(src, addr); |
281 | if (!src_pte) | |
282 | continue; | |
63551ae0 DG |
283 | dst_pte = huge_pte_alloc(dst, addr); |
284 | if (!dst_pte) | |
285 | goto nomem; | |
c74df32c | 286 | spin_lock(&dst->page_table_lock); |
1c59827d | 287 | spin_lock(&src->page_table_lock); |
c74df32c | 288 | if (!pte_none(*src_pte)) { |
1c59827d HD |
289 | entry = *src_pte; |
290 | ptepage = pte_page(entry); | |
291 | get_page(ptepage); | |
4294621f | 292 | add_mm_counter(dst, file_rss, HPAGE_SIZE / PAGE_SIZE); |
1c59827d HD |
293 | set_huge_pte_at(dst, addr, dst_pte, entry); |
294 | } | |
295 | spin_unlock(&src->page_table_lock); | |
c74df32c | 296 | spin_unlock(&dst->page_table_lock); |
63551ae0 DG |
297 | } |
298 | return 0; | |
299 | ||
300 | nomem: | |
301 | return -ENOMEM; | |
302 | } | |
303 | ||
304 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, | |
305 | unsigned long end) | |
306 | { | |
307 | struct mm_struct *mm = vma->vm_mm; | |
308 | unsigned long address; | |
c7546f8f | 309 | pte_t *ptep; |
63551ae0 DG |
310 | pte_t pte; |
311 | struct page *page; | |
312 | ||
313 | WARN_ON(!is_vm_hugetlb_page(vma)); | |
314 | BUG_ON(start & ~HPAGE_MASK); | |
315 | BUG_ON(end & ~HPAGE_MASK); | |
316 | ||
508034a3 HD |
317 | spin_lock(&mm->page_table_lock); |
318 | ||
365e9c87 HD |
319 | /* Update high watermark before we lower rss */ |
320 | update_hiwater_rss(mm); | |
321 | ||
63551ae0 | 322 | for (address = start; address < end; address += HPAGE_SIZE) { |
c7546f8f | 323 | ptep = huge_pte_offset(mm, address); |
4c887265 | 324 | if (!ptep) |
c7546f8f DG |
325 | continue; |
326 | ||
327 | pte = huge_ptep_get_and_clear(mm, address, ptep); | |
63551ae0 DG |
328 | if (pte_none(pte)) |
329 | continue; | |
c7546f8f | 330 | |
63551ae0 DG |
331 | page = pte_page(pte); |
332 | put_page(page); | |
4294621f | 333 | add_mm_counter(mm, file_rss, (int) -(HPAGE_SIZE / PAGE_SIZE)); |
63551ae0 | 334 | } |
63551ae0 | 335 | |
1da177e4 | 336 | spin_unlock(&mm->page_table_lock); |
508034a3 | 337 | flush_tlb_range(vma, start, end); |
1da177e4 | 338 | } |
63551ae0 | 339 | |
4c887265 AL |
340 | static struct page *find_lock_huge_page(struct address_space *mapping, |
341 | unsigned long idx) | |
63551ae0 | 342 | { |
4c887265 AL |
343 | struct page *page; |
344 | int err; | |
345 | struct inode *inode = mapping->host; | |
346 | unsigned long size; | |
347 | ||
348 | retry: | |
349 | page = find_lock_page(mapping, idx); | |
350 | if (page) | |
351 | goto out; | |
352 | ||
353 | /* Check to make sure the mapping hasn't been truncated */ | |
354 | size = i_size_read(inode) >> HPAGE_SHIFT; | |
355 | if (idx >= size) | |
356 | goto out; | |
357 | ||
358 | if (hugetlb_get_quota(mapping)) | |
359 | goto out; | |
360 | page = alloc_huge_page(); | |
361 | if (!page) { | |
362 | hugetlb_put_quota(mapping); | |
363 | goto out; | |
364 | } | |
63551ae0 | 365 | |
4c887265 AL |
366 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); |
367 | if (err) { | |
368 | put_page(page); | |
369 | hugetlb_put_quota(mapping); | |
370 | if (err == -EEXIST) | |
371 | goto retry; | |
372 | page = NULL; | |
63551ae0 DG |
373 | } |
374 | out: | |
4c887265 | 375 | return page; |
63551ae0 DG |
376 | } |
377 | ||
ac9b9c66 HD |
378 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
379 | unsigned long address, int write_access) | |
380 | { | |
381 | int ret = VM_FAULT_SIGBUS; | |
4c887265 AL |
382 | unsigned long idx; |
383 | unsigned long size; | |
ac9b9c66 | 384 | pte_t *pte; |
4c887265 AL |
385 | struct page *page; |
386 | struct address_space *mapping; | |
387 | ||
388 | pte = huge_pte_alloc(mm, address); | |
389 | if (!pte) | |
390 | goto out; | |
391 | ||
392 | mapping = vma->vm_file->f_mapping; | |
393 | idx = ((address - vma->vm_start) >> HPAGE_SHIFT) | |
394 | + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); | |
395 | ||
396 | /* | |
397 | * Use page lock to guard against racing truncation | |
398 | * before we get page_table_lock. | |
399 | */ | |
400 | page = find_lock_huge_page(mapping, idx); | |
401 | if (!page) | |
402 | goto out; | |
ac9b9c66 HD |
403 | |
404 | spin_lock(&mm->page_table_lock); | |
4c887265 AL |
405 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
406 | if (idx >= size) | |
407 | goto backout; | |
408 | ||
409 | ret = VM_FAULT_MINOR; | |
410 | if (!pte_none(*pte)) | |
411 | goto backout; | |
412 | ||
413 | add_mm_counter(mm, file_rss, HPAGE_SIZE / PAGE_SIZE); | |
414 | set_huge_pte_at(mm, address, pte, make_huge_pte(vma, page)); | |
ac9b9c66 | 415 | spin_unlock(&mm->page_table_lock); |
4c887265 AL |
416 | unlock_page(page); |
417 | out: | |
ac9b9c66 | 418 | return ret; |
4c887265 AL |
419 | |
420 | backout: | |
421 | spin_unlock(&mm->page_table_lock); | |
422 | hugetlb_put_quota(mapping); | |
423 | unlock_page(page); | |
424 | put_page(page); | |
425 | goto out; | |
ac9b9c66 HD |
426 | } |
427 | ||
63551ae0 DG |
428 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
429 | struct page **pages, struct vm_area_struct **vmas, | |
430 | unsigned long *position, int *length, int i) | |
431 | { | |
432 | unsigned long vpfn, vaddr = *position; | |
433 | int remainder = *length; | |
434 | ||
63551ae0 | 435 | vpfn = vaddr/PAGE_SIZE; |
1c59827d | 436 | spin_lock(&mm->page_table_lock); |
63551ae0 | 437 | while (vaddr < vma->vm_end && remainder) { |
4c887265 AL |
438 | pte_t *pte; |
439 | struct page *page; | |
63551ae0 | 440 | |
4c887265 AL |
441 | /* |
442 | * Some archs (sparc64, sh*) have multiple pte_ts to | |
443 | * each hugepage. We have to make * sure we get the | |
444 | * first, for the page indexing below to work. | |
445 | */ | |
446 | pte = huge_pte_offset(mm, vaddr & HPAGE_MASK); | |
63551ae0 | 447 | |
4c887265 AL |
448 | if (!pte || pte_none(*pte)) { |
449 | int ret; | |
63551ae0 | 450 | |
4c887265 AL |
451 | spin_unlock(&mm->page_table_lock); |
452 | ret = hugetlb_fault(mm, vma, vaddr, 0); | |
453 | spin_lock(&mm->page_table_lock); | |
454 | if (ret == VM_FAULT_MINOR) | |
455 | continue; | |
63551ae0 | 456 | |
4c887265 AL |
457 | remainder = 0; |
458 | if (!i) | |
459 | i = -EFAULT; | |
460 | break; | |
461 | } | |
462 | ||
463 | if (pages) { | |
464 | page = &pte_page(*pte)[vpfn % (HPAGE_SIZE/PAGE_SIZE)]; | |
63551ae0 DG |
465 | get_page(page); |
466 | pages[i] = page; | |
467 | } | |
468 | ||
469 | if (vmas) | |
470 | vmas[i] = vma; | |
471 | ||
472 | vaddr += PAGE_SIZE; | |
473 | ++vpfn; | |
474 | --remainder; | |
475 | ++i; | |
476 | } | |
1c59827d | 477 | spin_unlock(&mm->page_table_lock); |
63551ae0 DG |
478 | *length = remainder; |
479 | *position = vaddr; | |
480 | ||
481 | return i; | |
482 | } |