Introduce utility functions for zsdesc to avoid directly accessing fields
of struct page.
zsdesc_page() is defined this way to preserve constness. page_zsdesc() does
not call compound_head() because zsdesc is always a base page.
Signed-off-by: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>
---
mm/zsmalloc.c | 120 +++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 118 insertions(+), 2 deletions(-)
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index e2e34992c439..4af9f87cafb7 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -332,6 +332,124 @@ ZSDESC_MATCH(_refcount, _refcount);
#undef ZSDESC_MATCH
static_assert(sizeof(struct zsdesc) <= sizeof(struct page));
+#define zsdesc_page(zdesc) (_Generic((zdesc), \
+ const struct zsdesc *: (const struct page *)zdesc, \
+ struct zsdesc *: (struct page *)zdesc))
+
+static inline struct zsdesc *page_zsdesc(struct page *page)
+{
+ return (struct zsdesc *)page;
+}
+
+static inline unsigned long zsdesc_pfn(const struct zsdesc *zsdesc)
+{
+ return page_to_pfn(zsdesc_page(zsdesc));
+}
+
+static inline struct zsdesc *pfn_zsdesc(unsigned long pfn)
+{
+ return page_zsdesc(pfn_to_page(pfn));
+}
+
+static inline struct zspage *zsdesc_zspage(const struct zsdesc *zsdesc)
+{
+ return (struct zspage *)page_private(zsdesc_page(zsdesc));
+}
+
+static inline int trylock_zsdesc(struct zsdesc *zsdesc)
+{
+ return trylock_page(zsdesc_page(zsdesc));
+}
+
+static inline void unlock_zsdesc(struct zsdesc *zsdesc)
+{
+ return unlock_page(zsdesc_page(zsdesc));
+}
+
+static inline struct zone *zsdesc_zone(struct zsdesc *zsdesc)
+{
+ return page_zone(zsdesc_page(zsdesc));
+}
+
+static inline void wait_on_zsdesc_locked(struct zsdesc *zsdesc)
+{
+ wait_on_page_locked(zsdesc_page(zsdesc));
+}
+
+static inline void zsdesc_get(struct zsdesc *zsdesc)
+{
+ struct folio *folio = (struct folio *)zsdesc;
+
+ folio_get(folio);
+}
+
+static inline void zsdesc_put(struct zsdesc *zsdesc)
+{
+ struct folio *folio = (struct folio *)zsdesc;
+
+ folio_put(folio);
+}
+
+static inline void *zsdesc_kmap_atomic(struct zsdesc *zsdesc)
+{
+ return kmap_atomic(zsdesc_page(zsdesc));
+}
+
+static inline void zsdesc_set_zspage(struct zsdesc *zsdesc, struct zspage *zspage)
+{
+ set_page_private(zsdesc_page(zsdesc), (unsigned long)zspage);
+}
+
+static inline void zsdesc_set_first(struct zsdesc *zsdesc)
+{
+ SetPagePrivate(zsdesc_page(zsdesc));
+}
+
+static inline bool zsdesc_is_locked(struct zsdesc *zsdesc)
+{
+ return PageLocked(zsdesc_page(zsdesc));
+}
+
+static inline bool zsdesc_is_isolated(struct zsdesc *zsdesc)
+{
+ return PageIsolated(zsdesc_page(zsdesc));
+}
+
+static inline void zsdesc_inc_zone_page_state(struct zsdesc *zsdesc)
+{
+ inc_zone_page_state(zsdesc_page(zsdesc), NR_ZSPAGES);
+}
+
+static inline void zsdesc_dec_zone_page_state(struct zsdesc *zsdesc)
+{
+ dec_zone_page_state(zsdesc_page(zsdesc), NR_ZSPAGES);
+}
+
+static inline struct zsdesc *alloc_zsdesc(gfp_t gfp)
+{
+ struct page *page = alloc_page(gfp);
+
+ zsdesc_inc_zone_page_state(page_zsdesc(page));
+ return page_zsdesc(page);
+}
+
+static inline void free_zsdesc(struct zsdesc *zsdesc)
+{
+ struct page *page = zsdesc_page(zsdesc);
+
+ zsdesc_dec_zone_page_state(page_zsdesc(page));
+ __free_page(page);
+}
+
+static const struct movable_operations zsmalloc_mops;
+
+static inline void zsdesc_set_movable(struct zsdesc *zsdesc)
+{
+ struct page *page = zsdesc_page(zsdesc);
+
+ __SetPageMovable(page, &zsmalloc_mops);
+}
+
/* huge object: pages_per_zspage == 1 && maxobj_per_zspage == 1 */
static void SetZsHugePage(struct zspage *zspage)
{
@@ -2012,8 +2130,6 @@ static void dec_zspage_isolation(struct zspage *zspage)
zspage->isolated--;
}
-static const struct movable_operations zsmalloc_mops;
-
static void replace_sub_page(struct size_class *class, struct zspage *zspage,
struct page *newpage, struct page *oldpage)
{
--
2.25.1
