mm: introduce memdesc_is_zone_device()

Remove the conversion from folio to page in folio_is_zone_device() by
introducing memdesc_is_zone_device() which takes a memdesc_flags_t from
either a page or a folio.

Link: https://lkml.kernel.org/r/20250805172307.1302730-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 80a3b6642603d4ae52e0b1fa2c512d3fe9c8736b..fe13ad175fed8a473c8f5f11b733eab03bfed02a 100644 (file)
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -1200,14 +1200,14 @@ static inline enum zone_type folio_zonenum(const struct folio *folio)
 }
 
 #ifdef CONFIG_ZONE_DEVICE
-static inline bool is_zone_device_page(const struct page *page)
+static inline bool memdesc_is_zone_device(memdesc_flags_t mdf)
 {
-       return page_zonenum(page) == ZONE_DEVICE;
+       return memdesc_zonenum(mdf) == ZONE_DEVICE;
 }
 
 static inline struct dev_pagemap *page_pgmap(const struct page *page)
 {
-       VM_WARN_ON_ONCE_PAGE(!is_zone_device_page(page), page);
+       VM_WARN_ON_ONCE_PAGE(!memdesc_is_zone_device(page->flags), page);
        return page_folio(page)->pgmap;
 }
 
@@ -1222,9 +1222,9 @@ static inline struct dev_pagemap *page_pgmap(const struct page *page)
 static inline bool zone_device_pages_have_same_pgmap(const struct page *a,
                                                     const struct page *b)
 {
-       if (is_zone_device_page(a) != is_zone_device_page(b))
+       if (memdesc_is_zone_device(a->flags) != memdesc_is_zone_device(b->flags))
                return false;
-       if (!is_zone_device_page(a))
+       if (!memdesc_is_zone_device(a->flags))
                return true;
        return page_pgmap(a) == page_pgmap(b);
 }
@@ -1232,7 +1232,7 @@ static inline bool zone_device_pages_have_same_pgmap(const struct page *a,
 extern void memmap_init_zone_device(struct zone *, unsigned long,
                                    unsigned long, struct dev_pagemap *);
 #else
-static inline bool is_zone_device_page(const struct page *page)
+static inline bool memdesc_is_zone_device(memdesc_flags_t mdf)
 {
        return false;
 }
@@ -1247,9 +1247,14 @@ static inline struct dev_pagemap *page_pgmap(const struct page *page)
 }
 #endif
 
+static inline bool is_zone_device_page(const struct page *page)
+{
+       return memdesc_is_zone_device(page->flags);
+}
+
 static inline bool folio_is_zone_device(const struct folio *folio)
 {
-       return is_zone_device_page(&folio->page);
+       return memdesc_is_zone_device(folio->flags);
 }
 
 static inline bool is_zone_movable_page(const struct page *page)