[PATCH v4 17/25] memremap: Add is_device_dax_page() and is_fsdax_page() helpers

[Alistair Popple <apopple@nvidia.com>]

Add helpers to determine if a page or folio is a device dax or fs dax
page or folio.

Signed-off-by: Alistair Popple <apopple@nvidia.com>
---
 include/linux/memremap.h | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index 0256a42..f2a8d13 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -187,6 +187,28 @@ static inline bool folio_is_device_coherent(const struct folio *folio)
 	return is_device_coherent_page(&folio->page);
 }
 
+static inline bool is_fsdax_page(const struct page *page)
+{
+	return is_zone_device_page(page) &&
+		page_pgmap(page)->type == MEMORY_DEVICE_FS_DAX;
+}
+
+static inline bool folio_is_fsdax(const struct folio *folio)
+{
+	return is_fsdax_page(&folio->page);
+}
+
+static inline bool is_device_dax_page(const struct page *page)
+{
+	return is_zone_device_page(page) &&
+		page_pgmap(page)->type == MEMORY_DEVICE_GENERIC;
+}
+
+static inline bool folio_is_device_dax(const struct folio *folio)
+{
+	return is_device_dax_page(&folio->page);
+}
+
 #ifdef CONFIG_ZONE_DEVICE
 void zone_device_page_init(struct page *page);
 void *memremap_pages(struct dev_pagemap *pgmap, int nid);
-- 
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