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 | ||
3c726f8d BH |
106 | if (HPAGE_SHIFT == 0) |
107 | return 0; | |
108 | ||
1da177e4 LT |
109 | for (i = 0; i < MAX_NUMNODES; ++i) |
110 | INIT_LIST_HEAD(&hugepage_freelists[i]); | |
111 | ||
112 | for (i = 0; i < max_huge_pages; ++i) { | |
113 | page = alloc_fresh_huge_page(); | |
114 | if (!page) | |
115 | break; | |
116 | spin_lock(&hugetlb_lock); | |
117 | enqueue_huge_page(page); | |
118 | spin_unlock(&hugetlb_lock); | |
119 | } | |
120 | max_huge_pages = free_huge_pages = nr_huge_pages = i; | |
121 | printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages); | |
122 | return 0; | |
123 | } | |
124 | module_init(hugetlb_init); | |
125 | ||
126 | static int __init hugetlb_setup(char *s) | |
127 | { | |
128 | if (sscanf(s, "%lu", &max_huge_pages) <= 0) | |
129 | max_huge_pages = 0; | |
130 | return 1; | |
131 | } | |
132 | __setup("hugepages=", hugetlb_setup); | |
133 | ||
134 | #ifdef CONFIG_SYSCTL | |
135 | static void update_and_free_page(struct page *page) | |
136 | { | |
137 | int i; | |
138 | nr_huge_pages--; | |
139 | nr_huge_pages_node[page_zone(page)->zone_pgdat->node_id]--; | |
140 | for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) { | |
141 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | | |
142 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | | |
143 | 1 << PG_private | 1<< PG_writeback); | |
144 | set_page_count(&page[i], 0); | |
145 | } | |
146 | set_page_count(page, 1); | |
147 | __free_pages(page, HUGETLB_PAGE_ORDER); | |
148 | } | |
149 | ||
150 | #ifdef CONFIG_HIGHMEM | |
151 | static void try_to_free_low(unsigned long count) | |
152 | { | |
153 | int i, nid; | |
154 | for (i = 0; i < MAX_NUMNODES; ++i) { | |
155 | struct page *page, *next; | |
156 | list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) { | |
157 | if (PageHighMem(page)) | |
158 | continue; | |
159 | list_del(&page->lru); | |
160 | update_and_free_page(page); | |
161 | nid = page_zone(page)->zone_pgdat->node_id; | |
162 | free_huge_pages--; | |
163 | free_huge_pages_node[nid]--; | |
164 | if (count >= nr_huge_pages) | |
165 | return; | |
166 | } | |
167 | } | |
168 | } | |
169 | #else | |
170 | static inline void try_to_free_low(unsigned long count) | |
171 | { | |
172 | } | |
173 | #endif | |
174 | ||
175 | static unsigned long set_max_huge_pages(unsigned long count) | |
176 | { | |
177 | while (count > nr_huge_pages) { | |
178 | struct page *page = alloc_fresh_huge_page(); | |
179 | if (!page) | |
180 | return nr_huge_pages; | |
181 | spin_lock(&hugetlb_lock); | |
182 | enqueue_huge_page(page); | |
183 | spin_unlock(&hugetlb_lock); | |
184 | } | |
185 | if (count >= nr_huge_pages) | |
186 | return nr_huge_pages; | |
187 | ||
188 | spin_lock(&hugetlb_lock); | |
189 | try_to_free_low(count); | |
190 | while (count < nr_huge_pages) { | |
191 | struct page *page = dequeue_huge_page(); | |
192 | if (!page) | |
193 | break; | |
194 | update_and_free_page(page); | |
195 | } | |
196 | spin_unlock(&hugetlb_lock); | |
197 | return nr_huge_pages; | |
198 | } | |
199 | ||
200 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, | |
201 | struct file *file, void __user *buffer, | |
202 | size_t *length, loff_t *ppos) | |
203 | { | |
204 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); | |
205 | max_huge_pages = set_max_huge_pages(max_huge_pages); | |
206 | return 0; | |
207 | } | |
208 | #endif /* CONFIG_SYSCTL */ | |
209 | ||
210 | int hugetlb_report_meminfo(char *buf) | |
211 | { | |
212 | return sprintf(buf, | |
213 | "HugePages_Total: %5lu\n" | |
214 | "HugePages_Free: %5lu\n" | |
215 | "Hugepagesize: %5lu kB\n", | |
216 | nr_huge_pages, | |
217 | free_huge_pages, | |
218 | HPAGE_SIZE/1024); | |
219 | } | |
220 | ||
221 | int hugetlb_report_node_meminfo(int nid, char *buf) | |
222 | { | |
223 | return sprintf(buf, | |
224 | "Node %d HugePages_Total: %5u\n" | |
225 | "Node %d HugePages_Free: %5u\n", | |
226 | nid, nr_huge_pages_node[nid], | |
227 | nid, free_huge_pages_node[nid]); | |
228 | } | |
229 | ||
230 | int is_hugepage_mem_enough(size_t size) | |
231 | { | |
232 | return (size + ~HPAGE_MASK)/HPAGE_SIZE <= free_huge_pages; | |
233 | } | |
234 | ||
235 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ | |
236 | unsigned long hugetlb_total_pages(void) | |
237 | { | |
238 | return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE); | |
239 | } | |
1da177e4 LT |
240 | |
241 | /* | |
242 | * We cannot handle pagefaults against hugetlb pages at all. They cause | |
243 | * handle_mm_fault() to try to instantiate regular-sized pages in the | |
244 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get | |
245 | * this far. | |
246 | */ | |
247 | static struct page *hugetlb_nopage(struct vm_area_struct *vma, | |
248 | unsigned long address, int *unused) | |
249 | { | |
250 | BUG(); | |
251 | return NULL; | |
252 | } | |
253 | ||
254 | struct vm_operations_struct hugetlb_vm_ops = { | |
255 | .nopage = hugetlb_nopage, | |
256 | }; | |
257 | ||
63551ae0 DG |
258 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page) |
259 | { | |
260 | pte_t entry; | |
261 | ||
262 | if (vma->vm_flags & VM_WRITE) { | |
263 | entry = | |
264 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); | |
265 | } else { | |
266 | entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot)); | |
267 | } | |
268 | entry = pte_mkyoung(entry); | |
269 | entry = pte_mkhuge(entry); | |
270 | ||
271 | return entry; | |
272 | } | |
273 | ||
274 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, | |
275 | struct vm_area_struct *vma) | |
276 | { | |
277 | pte_t *src_pte, *dst_pte, entry; | |
278 | struct page *ptepage; | |
1c59827d | 279 | unsigned long addr; |
63551ae0 | 280 | |
1c59827d | 281 | for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) { |
c74df32c HD |
282 | src_pte = huge_pte_offset(src, addr); |
283 | if (!src_pte) | |
284 | continue; | |
63551ae0 DG |
285 | dst_pte = huge_pte_alloc(dst, addr); |
286 | if (!dst_pte) | |
287 | goto nomem; | |
c74df32c | 288 | spin_lock(&dst->page_table_lock); |
1c59827d | 289 | spin_lock(&src->page_table_lock); |
c74df32c | 290 | if (!pte_none(*src_pte)) { |
1c59827d HD |
291 | entry = *src_pte; |
292 | ptepage = pte_page(entry); | |
293 | get_page(ptepage); | |
4294621f | 294 | add_mm_counter(dst, file_rss, HPAGE_SIZE / PAGE_SIZE); |
1c59827d HD |
295 | set_huge_pte_at(dst, addr, dst_pte, entry); |
296 | } | |
297 | spin_unlock(&src->page_table_lock); | |
c74df32c | 298 | spin_unlock(&dst->page_table_lock); |
63551ae0 DG |
299 | } |
300 | return 0; | |
301 | ||
302 | nomem: | |
303 | return -ENOMEM; | |
304 | } | |
305 | ||
306 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, | |
307 | unsigned long end) | |
308 | { | |
309 | struct mm_struct *mm = vma->vm_mm; | |
310 | unsigned long address; | |
c7546f8f | 311 | pte_t *ptep; |
63551ae0 DG |
312 | pte_t pte; |
313 | struct page *page; | |
314 | ||
315 | WARN_ON(!is_vm_hugetlb_page(vma)); | |
316 | BUG_ON(start & ~HPAGE_MASK); | |
317 | BUG_ON(end & ~HPAGE_MASK); | |
318 | ||
508034a3 HD |
319 | spin_lock(&mm->page_table_lock); |
320 | ||
365e9c87 HD |
321 | /* Update high watermark before we lower rss */ |
322 | update_hiwater_rss(mm); | |
323 | ||
63551ae0 | 324 | for (address = start; address < end; address += HPAGE_SIZE) { |
c7546f8f | 325 | ptep = huge_pte_offset(mm, address); |
4c887265 | 326 | if (!ptep) |
c7546f8f DG |
327 | continue; |
328 | ||
329 | pte = huge_ptep_get_and_clear(mm, address, ptep); | |
63551ae0 DG |
330 | if (pte_none(pte)) |
331 | continue; | |
c7546f8f | 332 | |
63551ae0 DG |
333 | page = pte_page(pte); |
334 | put_page(page); | |
4294621f | 335 | add_mm_counter(mm, file_rss, (int) -(HPAGE_SIZE / PAGE_SIZE)); |
63551ae0 | 336 | } |
63551ae0 | 337 | |
1da177e4 | 338 | spin_unlock(&mm->page_table_lock); |
508034a3 | 339 | flush_tlb_range(vma, start, end); |
1da177e4 | 340 | } |
63551ae0 | 341 | |
4c887265 AL |
342 | static struct page *find_lock_huge_page(struct address_space *mapping, |
343 | unsigned long idx) | |
63551ae0 | 344 | { |
4c887265 AL |
345 | struct page *page; |
346 | int err; | |
347 | struct inode *inode = mapping->host; | |
348 | unsigned long size; | |
349 | ||
350 | retry: | |
351 | page = find_lock_page(mapping, idx); | |
352 | if (page) | |
353 | goto out; | |
354 | ||
355 | /* Check to make sure the mapping hasn't been truncated */ | |
356 | size = i_size_read(inode) >> HPAGE_SHIFT; | |
357 | if (idx >= size) | |
358 | goto out; | |
359 | ||
360 | if (hugetlb_get_quota(mapping)) | |
361 | goto out; | |
362 | page = alloc_huge_page(); | |
363 | if (!page) { | |
364 | hugetlb_put_quota(mapping); | |
365 | goto out; | |
366 | } | |
63551ae0 | 367 | |
4c887265 AL |
368 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); |
369 | if (err) { | |
370 | put_page(page); | |
371 | hugetlb_put_quota(mapping); | |
372 | if (err == -EEXIST) | |
373 | goto retry; | |
374 | page = NULL; | |
63551ae0 DG |
375 | } |
376 | out: | |
4c887265 | 377 | return page; |
63551ae0 DG |
378 | } |
379 | ||
ac9b9c66 HD |
380 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
381 | unsigned long address, int write_access) | |
382 | { | |
383 | int ret = VM_FAULT_SIGBUS; | |
4c887265 AL |
384 | unsigned long idx; |
385 | unsigned long size; | |
ac9b9c66 | 386 | pte_t *pte; |
4c887265 AL |
387 | struct page *page; |
388 | struct address_space *mapping; | |
389 | ||
390 | pte = huge_pte_alloc(mm, address); | |
391 | if (!pte) | |
392 | goto out; | |
393 | ||
394 | mapping = vma->vm_file->f_mapping; | |
395 | idx = ((address - vma->vm_start) >> HPAGE_SHIFT) | |
396 | + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); | |
397 | ||
398 | /* | |
399 | * Use page lock to guard against racing truncation | |
400 | * before we get page_table_lock. | |
401 | */ | |
402 | page = find_lock_huge_page(mapping, idx); | |
403 | if (!page) | |
404 | goto out; | |
ac9b9c66 HD |
405 | |
406 | spin_lock(&mm->page_table_lock); | |
4c887265 AL |
407 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
408 | if (idx >= size) | |
409 | goto backout; | |
410 | ||
411 | ret = VM_FAULT_MINOR; | |
412 | if (!pte_none(*pte)) | |
413 | goto backout; | |
414 | ||
415 | add_mm_counter(mm, file_rss, HPAGE_SIZE / PAGE_SIZE); | |
416 | set_huge_pte_at(mm, address, pte, make_huge_pte(vma, page)); | |
ac9b9c66 | 417 | spin_unlock(&mm->page_table_lock); |
4c887265 AL |
418 | unlock_page(page); |
419 | out: | |
ac9b9c66 | 420 | return ret; |
4c887265 AL |
421 | |
422 | backout: | |
423 | spin_unlock(&mm->page_table_lock); | |
424 | hugetlb_put_quota(mapping); | |
425 | unlock_page(page); | |
426 | put_page(page); | |
427 | goto out; | |
ac9b9c66 HD |
428 | } |
429 | ||
63551ae0 DG |
430 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
431 | struct page **pages, struct vm_area_struct **vmas, | |
432 | unsigned long *position, int *length, int i) | |
433 | { | |
434 | unsigned long vpfn, vaddr = *position; | |
435 | int remainder = *length; | |
436 | ||
63551ae0 | 437 | vpfn = vaddr/PAGE_SIZE; |
1c59827d | 438 | spin_lock(&mm->page_table_lock); |
63551ae0 | 439 | while (vaddr < vma->vm_end && remainder) { |
4c887265 AL |
440 | pte_t *pte; |
441 | struct page *page; | |
63551ae0 | 442 | |
4c887265 AL |
443 | /* |
444 | * Some archs (sparc64, sh*) have multiple pte_ts to | |
445 | * each hugepage. We have to make * sure we get the | |
446 | * first, for the page indexing below to work. | |
447 | */ | |
448 | pte = huge_pte_offset(mm, vaddr & HPAGE_MASK); | |
63551ae0 | 449 | |
4c887265 AL |
450 | if (!pte || pte_none(*pte)) { |
451 | int ret; | |
63551ae0 | 452 | |
4c887265 AL |
453 | spin_unlock(&mm->page_table_lock); |
454 | ret = hugetlb_fault(mm, vma, vaddr, 0); | |
455 | spin_lock(&mm->page_table_lock); | |
456 | if (ret == VM_FAULT_MINOR) | |
457 | continue; | |
63551ae0 | 458 | |
4c887265 AL |
459 | remainder = 0; |
460 | if (!i) | |
461 | i = -EFAULT; | |
462 | break; | |
463 | } | |
464 | ||
465 | if (pages) { | |
466 | page = &pte_page(*pte)[vpfn % (HPAGE_SIZE/PAGE_SIZE)]; | |
63551ae0 DG |
467 | get_page(page); |
468 | pages[i] = page; | |
469 | } | |
470 | ||
471 | if (vmas) | |
472 | vmas[i] = vma; | |
473 | ||
474 | vaddr += PAGE_SIZE; | |
475 | ++vpfn; | |
476 | --remainder; | |
477 | ++i; | |
478 | } | |
1c59827d | 479 | spin_unlock(&mm->page_table_lock); |
63551ae0 DG |
480 | *length = remainder; |
481 | *position = vaddr; | |
482 | ||
483 | return i; | |
484 | } |