diff options
Diffstat (limited to 'mm/gup.c')
| -rw-r--r-- | mm/gup.c | 62 |
1 files changed, 62 insertions, 0 deletions
@@ -213,6 +213,32 @@ void unpin_user_page(struct page *page) } EXPORT_SYMBOL(unpin_user_page); +static inline void compound_range_next(unsigned long i, unsigned long npages, + struct page **list, struct page **head, + unsigned int *ntails) +{ + struct page *next, *page; + unsigned int nr = 1; + + if (i >= npages) + return; + + next = *list + i; + page = compound_head(next); + if (PageCompound(page) && compound_order(page) >= 1) + nr = min_t(unsigned int, + page + compound_nr(page) - next, npages - i); + + *head = page; + *ntails = nr; +} + +#define for_each_compound_range(__i, __list, __npages, __head, __ntails) \ + for (__i = 0, \ + compound_range_next(__i, __npages, __list, &(__head), &(__ntails)); \ + __i < __npages; __i += __ntails, \ + compound_range_next(__i, __npages, __list, &(__head), &(__ntails))) + static inline void compound_next(unsigned long i, unsigned long npages, struct page **list, struct page **head, unsigned int *ntails) @@ -302,6 +328,42 @@ void unpin_user_pages_dirty_lock(struct page **pages, unsigned long npages, EXPORT_SYMBOL(unpin_user_pages_dirty_lock); /** + * unpin_user_page_range_dirty_lock() - release and optionally dirty + * gup-pinned page range + * + * @page: the starting page of a range maybe marked dirty, and definitely released. + * @npages: number of consecutive pages to release. + * @make_dirty: whether to mark the pages dirty + * + * "gup-pinned page range" refers to a range of pages that has had one of the + * pin_user_pages() variants called on that page. + * + * For the page ranges defined by [page .. page+npages], make that range (or + * its head pages, if a compound page) dirty, if @make_dirty is true, and if the + * page range was previously listed as clean. + * + * set_page_dirty_lock() is used internally. If instead, set_page_dirty() is + * required, then the caller should a) verify that this is really correct, + * because _lock() is usually required, and b) hand code it: + * set_page_dirty_lock(), unpin_user_page(). + * + */ +void unpin_user_page_range_dirty_lock(struct page *page, unsigned long npages, + bool make_dirty) +{ + unsigned long index; + struct page *head; + unsigned int ntails; + + for_each_compound_range(index, &page, npages, head, ntails) { + if (make_dirty && !PageDirty(head)) + set_page_dirty_lock(head); + put_compound_head(head, ntails, FOLL_PIN); + } +} +EXPORT_SYMBOL(unpin_user_page_range_dirty_lock); + +/** * unpin_user_pages() - release an array of gup-pinned pages. * @pages: array of pages to be marked dirty and released. * @npages: number of pages in the @pages array. |