linux-6.12.1/mm/gup.c

42 	 * We only pin anonymous pages if they are exclusive. Once pinned, we  in sanity_check_pinned_pages()
46 	 * We'd like to verify that our pinned anonymous pages are still mapped  in sanity_check_pinned_pages()
162 		 * so that the page really is pinned.  in try_grab_folio()
178  * unpin_user_page() - release a dma-pinned page
181  * Pages that were pinned via pin_user_pages*() must be released via either
194  * unpin_folio() - release a dma-pinned folio
197  * Folios that were pinned via memfd_pin_folios() or other similar routines
207  * folio_add_pin - Try to get an additional pin on a pinned folio
208  * @folio: The folio to be pinned
221 	 * pinned.  in folio_add_pin()
264  * unpin_user_pages_dirty_lock() - release and optionally dirty gup-pinned pages
269  * "gup-pinned page" refers to a page that has had one of the get_user_pages()
332  * gup-pinned page range
338  * "gup-pinned page range" refers to a range of pages that has had one of the
388  * unpin_user_pages() - release an array of gup-pinned pages.
404 	 * leaving them pinned), but probably not. More likely, gup/pup returned  in unpin_user_pages()
432  * unpin_folios() - release an array of gup-pinned folios.
446 	 * (by leaving them pinned), but probably not. More likely, gup/pup  in unpin_folios()
468  * cache bouncing on large SMP machines for concurrent pinned gups.
569 	 * is pinned.  That's why the refcount from the earlier  in try_grab_folio_fast()
1367  * @pages:	array that receives pointers to the pages pinned.
1372  * Returns either number of pages pinned (which may be less than the
1376  * -- If nr_pages is >0, but no pages were pinned, returns -errno.
1377  * -- If nr_pages is >0, and some pages were pinned, returns the number of
1378  *    pages pinned. Again, this may be less than nr_pages.
1865  * Return either number of pages pinned in the vma, or a negative error
2252  * Returns struct page pointer of user page pinned for dump,
2379 			 * Migration will fail if the folio is pinned, so  in migrate_longterm_unpinnable_folios()
2447  * Check whether all folios are *allowed* to be pinned indefinitely (long term).
2448  * Rather confusingly, all folios in the range are required to be pinned via
2453  * 0: if everything is OK and all folios in the range are allowed to be pinned,
2454  * then this routine leaves all folios pinned and returns zero for success.
2456  * -EAGAIN: if any folios in the range are not allowed to be pinned, then this
2600  * @pages:	array that receives pointers to the pages pinned.
2607  * Returns either number of pages pinned (which may be less than the
2611  * -- If nr_pages is >0, but no pages were pinned, returns -errno.
2612  * -- If nr_pages is >0, and some pages were pinned, returns the number of
2613  *    pages pinned. Again, this may be less than nr_pages.
2682  * @pages:      array that receives pointers to the pages pinned.
2771  * This call assumes the caller has pinned the folio, that the lowest page table
2776  * Writing to pinned file-backed dirty tracked folios is inherently problematic
2877  * is pinned.
3430 		 * The caller has to unpin the pages we already pinned so  in gup_fast_fallback()
3445  * @pages:      array that receives pointers to the pages pinned.
3452  * pages pinned.
3481  * @pages:      array that receives pointers to the pages pinned.
3488  * Returns number of pages pinned. This may be fewer than the number requested.
3489  * If nr_pages is 0 or negative, returns 0. If no pages were pinned, returns
3513  * @pages:      array that receives pointers to the pages pinned.
3542  * @pages:	array that receives pointers to the pages pinned.
3580  * @pages:	array that receives pointers to the pages pinned.
3628  * @memfd:      the memfd whose folios are to be pinned
3631  * @folios:     array that receives pointers to the folios pinned
3638  * if necessary. Once the folios are located, they are all pinned via
3640  * And, eventually, these pinned folios must be released either using
3643  * It must be noted that the folios may be pinned for an indefinite amount
3644  * of time. And, in most cases, the duration of time they may stay pinned
3648  * Returns number of folios pinned, which could be less than @max_folios
3650  * If no folios were pinned, it returns -errno.