2 files changed, 38 insertions, 15 deletions
diff --git a/include/linux/io.h b/include/linux/io.h
index de64c1e53612..fffd88d7f426 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -89,21 +89,6 @@ void devm_memunmap(struct device *dev, void *addr);
 
 void *__devm_memremap_pages(struct device *dev, struct resource *res);
 
-#ifdef CONFIG_ZONE_DEVICE
-void *devm_memremap_pages(struct device *dev, struct resource *res);
-#else
-static inline void *devm_memremap_pages(struct device *dev, struct resource *res)
-{
-	/*
-	 * Fail attempts to call devm_memremap_pages() without
-	 * ZONE_DEVICE support enabled, this requires callers to fall
-	 * back to plain devm_memremap() based on config
-	 */
-	WARN_ON_ONCE(1);
-	return ERR_PTR(-ENXIO);
-}
-#endif
-
 /*
  * Some systems do not have legacy ISA devices.
  * /dev/port is not a valid interface on these systems.
diff --git a/include/linux/memremap.h b/include/linux/memremap.h
new file mode 100644
index 000000000000..d90721c178bb
--- /dev/null
+++ b/include/linux/memremap.h
@@ -0,0 +1,38 @@
+#ifndef _LINUX_MEMREMAP_H_
+#define _LINUX_MEMREMAP_H_
+#include <linux/mm.h>
+
+struct resource;
+struct device;
+/**
+ * struct dev_pagemap - metadata for ZONE_DEVICE mappings
+ * @dev: host device of the mapping for debug
+ */
+struct dev_pagemap {
+	/* TODO: vmem_altmap and percpu_ref count */
+	struct device *dev;
+};
+
+#ifdef CONFIG_ZONE_DEVICE
+void *devm_memremap_pages(struct device *dev, struct resource *res);
+struct dev_pagemap *find_dev_pagemap(resource_size_t phys);
+#else
+static inline void *devm_memremap_pages(struct device *dev,
+		struct resource *res)
+{
+	/*
+	 * Fail attempts to call devm_memremap_pages() without
+	 * ZONE_DEVICE support enabled, this requires callers to fall
+	 * back to plain devm_memremap() based on config
+	 */
+	WARN_ON_ONCE(1);
+	return ERR_PTR(-ENXIO);
+}
+
+static inline struct dev_pagemap *find_dev_pagemap(resource_size_t phys)
+{
+	return NULL;
+}
+#endif
+
+#endif /* _LINUX_MEMREMAP_H_ */