diff mbox series

[05/18] mm: swap: introduce pfn_swap_entry_to_folio()

Message ID 20231103140119.2306578-6-wangkefeng.wang@huawei.com (mailing list archive)
State New
Headers show
Series mm: convert to use folio mm counter | expand

Commit Message

Kefeng Wang Nov. 3, 2023, 2:01 p.m. UTC 
Introduce a new pfn_swap_entry_to_folio(), it is similar to
pfn_swap_entry_to_page(), but return a folio, which allow us
to completely replace the struct page variables with struct
folio variables.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 include/linux/swapops.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)
diff mbox series

Patch

diff --git a/include/linux/swapops.h b/include/linux/swapops.h
index bff1e8d97de0..85cb84e4be95 100644
--- a/include/linux/swapops.h
+++ b/include/linux/swapops.h
@@ -468,6 +468,19 @@  static inline struct page *pfn_swap_entry_to_page(swp_entry_t entry)
 	return p;
 }
 
+static inline struct folio *pfn_swap_entry_to_folio(swp_entry_t entry)
+{
+	struct folio *folio = pfn_folio(swp_offset_pfn(entry));
+
+	/*
+	 * Any use of migration entries may only occur while the
+	 * corresponding folio is locked
+	 */
+	BUG_ON(is_migration_entry(entry) && !folio_test_locked(folio));
+
+	return folio;
+}
+
 /*
  * A pfn swap entry is a special type of swap entry that always has a pfn stored
  * in the swap offset. They are used to represent unaddressable device memory