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-rw-r--r--mm/hugetlb.c177
1 files changed, 176 insertions, 1 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 4eb5ae3fbe10..fbd1111ea119 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -7,10 +7,14 @@
7#include <linux/init.h> 7#include <linux/init.h>
8#include <linux/module.h> 8#include <linux/module.h>
9#include <linux/mm.h> 9#include <linux/mm.h>
10#include <linux/hugetlb.h>
11#include <linux/sysctl.h> 10#include <linux/sysctl.h>
12#include <linux/highmem.h> 11#include <linux/highmem.h>
13#include <linux/nodemask.h> 12#include <linux/nodemask.h>
13#include <linux/pagemap.h>
14#include <asm/page.h>
15#include <asm/pgtable.h>
16
17#include <linux/hugetlb.h>
14 18
15const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; 19const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL;
16static unsigned long nr_huge_pages, free_huge_pages; 20static unsigned long nr_huge_pages, free_huge_pages;
@@ -249,6 +253,72 @@ struct vm_operations_struct hugetlb_vm_ops = {
249 .nopage = hugetlb_nopage, 253 .nopage = hugetlb_nopage,
250}; 254};
251 255
256static 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
272int 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;
277 unsigned long addr = vma->vm_start;
278 unsigned long end = vma->vm_end;
279
280 while (addr < end) {
281 dst_pte = huge_pte_alloc(dst, addr);
282 if (!dst_pte)
283 goto nomem;
284 src_pte = huge_pte_offset(src, addr);
285 BUG_ON(!src_pte || pte_none(*src_pte)); /* prefaulted */
286 entry = *src_pte;
287 ptepage = pte_page(entry);
288 get_page(ptepage);
289 add_mm_counter(dst, rss, HPAGE_SIZE / PAGE_SIZE);
290 set_huge_pte_at(dst, addr, dst_pte, entry);
291 addr += HPAGE_SIZE;
292 }
293 return 0;
294
295nomem:
296 return -ENOMEM;
297}
298
299void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
300 unsigned long end)
301{
302 struct mm_struct *mm = vma->vm_mm;
303 unsigned long address;
304 pte_t pte;
305 struct page *page;
306
307 WARN_ON(!is_vm_hugetlb_page(vma));
308 BUG_ON(start & ~HPAGE_MASK);
309 BUG_ON(end & ~HPAGE_MASK);
310
311 for (address = start; address < end; address += HPAGE_SIZE) {
312 pte = huge_ptep_get_and_clear(mm, address, huge_pte_offset(mm, address));
313 if (pte_none(pte))
314 continue;
315 page = pte_page(pte);
316 put_page(page);
317 }
318 add_mm_counter(mm, rss, -((end - start) >> PAGE_SHIFT));
319 flush_tlb_range(vma, start, end);
320}
321
252void zap_hugepage_range(struct vm_area_struct *vma, 322void zap_hugepage_range(struct vm_area_struct *vma,
253 unsigned long start, unsigned long length) 323 unsigned long start, unsigned long length)
254{ 324{
@@ -258,3 +328,108 @@ void zap_hugepage_range(struct vm_area_struct *vma,
258 unmap_hugepage_range(vma, start, start + length); 328 unmap_hugepage_range(vma, start, start + length);
259 spin_unlock(&mm->page_table_lock); 329 spin_unlock(&mm->page_table_lock);
260} 330}
331
332int hugetlb_prefault(struct address_space *mapping, struct vm_area_struct *vma)
333{
334 struct mm_struct *mm = current->mm;
335 unsigned long addr;
336 int ret = 0;
337
338 WARN_ON(!is_vm_hugetlb_page(vma));
339 BUG_ON(vma->vm_start & ~HPAGE_MASK);
340 BUG_ON(vma->vm_end & ~HPAGE_MASK);
341
342 hugetlb_prefault_arch_hook(mm);
343
344 spin_lock(&mm->page_table_lock);
345 for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) {
346 unsigned long idx;
347 pte_t *pte = huge_pte_alloc(mm, addr);
348 struct page *page;
349
350 if (!pte) {
351 ret = -ENOMEM;
352 goto out;
353 }
354 if (! pte_none(*pte))
355 hugetlb_clean_stale_pgtable(pte);
356
357 idx = ((addr - vma->vm_start) >> HPAGE_SHIFT)
358 + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT));
359 page = find_get_page(mapping, idx);
360 if (!page) {
361 /* charge the fs quota first */
362 if (hugetlb_get_quota(mapping)) {
363 ret = -ENOMEM;
364 goto out;
365 }
366 page = alloc_huge_page();
367 if (!page) {
368 hugetlb_put_quota(mapping);
369 ret = -ENOMEM;
370 goto out;
371 }
372 ret = add_to_page_cache(page, mapping, idx, GFP_ATOMIC);
373 if (! ret) {
374 unlock_page(page);
375 } else {
376 hugetlb_put_quota(mapping);
377 free_huge_page(page);
378 goto out;
379 }
380 }
381 add_mm_counter(mm, rss, HPAGE_SIZE / PAGE_SIZE);
382 set_huge_pte_at(mm, addr, pte, make_huge_pte(vma, page));
383 }
384out:
385 spin_unlock(&mm->page_table_lock);
386 return ret;
387}
388
389int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
390 struct page **pages, struct vm_area_struct **vmas,
391 unsigned long *position, int *length, int i)
392{
393 unsigned long vpfn, vaddr = *position;
394 int remainder = *length;
395
396 BUG_ON(!is_vm_hugetlb_page(vma));
397
398 vpfn = vaddr/PAGE_SIZE;
399 while (vaddr < vma->vm_end && remainder) {
400
401 if (pages) {
402 pte_t *pte;
403 struct page *page;
404
405 /* Some archs (sparc64, sh*) have multiple
406 * pte_ts to each hugepage. We have to make
407 * sure we get the first, for the page
408 * indexing below to work. */
409 pte = huge_pte_offset(mm, vaddr & HPAGE_MASK);
410
411 /* hugetlb should be locked, and hence, prefaulted */
412 WARN_ON(!pte || pte_none(*pte));
413
414 page = &pte_page(*pte)[vpfn % (HPAGE_SIZE/PAGE_SIZE)];
415
416 WARN_ON(!PageCompound(page));
417
418 get_page(page);
419 pages[i] = page;
420 }
421
422 if (vmas)
423 vmas[i] = vma;
424
425 vaddr += PAGE_SIZE;
426 ++vpfn;
427 --remainder;
428 ++i;
429 }
430
431 *length = remainder;
432 *position = vaddr;
433
434 return i;
435}