@@ -196,20 +196,20 @@ INCORRECT (uses FOLL_GET calls):
write to the data within the pages
put_page()
-page_maybe_dma_pinned(): the whole point of pinning
+folio_maybe_dma_pinned(): the whole point of pinning
===================================================
-The whole point of marking pages as "DMA-pinned" or "gup-pinned" is to be able
-to query, "is this page DMA-pinned?" That allows code such as page_mkclean()
+The whole point of marking folios as "DMA-pinned" or "gup-pinned" is to be able
+to query, "is this folio DMA-pinned?" That allows code such as page_mkclean()
(and file system writeback code in general) to make informed decisions about
-what to do when a page cannot be unmapped due to such pins.
+what to do when a folio cannot be unmapped due to such pins.
What to do in those cases is the subject of a years-long series of discussions
and debates (see the References at the end of this document). It's a TODO item
here: fill in the details once that's worked out. Meanwhile, it's safe to say
that having this available: ::
- static inline bool page_maybe_dma_pinned(struct page *page)
+ static inline bool folio_maybe_dma_pinned(struct folio *folio)
...is a prerequisite to solving the long-running gup+DMA problem.
@@ -1953,8 +1953,8 @@ static inline struct folio *pfn_folio(unsigned long pfn)
*
* For more information, please see Documentation/core-api/pin_user_pages.rst.
*
- * Return: True, if it is likely that the page has been "dma-pinned".
- * False, if the page is definitely not dma-pinned.
+ * Return: True, if it is likely that the folio has been "dma-pinned".
+ * False, if the folio is definitely not dma-pinned.
*/
static inline bool folio_maybe_dma_pinned(struct folio *folio)
{
@@ -1973,11 +1973,6 @@ static inline bool folio_maybe_dma_pinned(struct folio *folio)
GUP_PIN_COUNTING_BIAS;
}
-static inline bool page_maybe_dma_pinned(struct page *page)
-{
- return folio_maybe_dma_pinned(page_folio(page));
-}
-
/*
* This should most likely only be called during fork() to see whether we
* should break the cow immediately for an anon page on the src mm.
After the last user of page_maybe_dma_pinned() is converted to folio_maybe_dma_pinned(), remove page_maybe_dma_pinned() and update the document and comment. Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> --- Documentation/core-api/pin_user_pages.rst | 10 +++++----- include/linux/mm.h | 9 ++------- 2 files changed, 7 insertions(+), 12 deletions(-)