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Diffstat (limited to 'include/linux/memremap.h')
-rw-r--r--include/linux/memremap.h11
1 files changed, 11 insertions, 0 deletions
diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index a8bc588fe7aa..1fafcc38acba 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -88,6 +88,11 @@ struct dev_pagemap_ops {
* @done: completion for @ref
* @type: memory type: see MEMORY_* in memory_hotplug.h
* @flags: PGMAP_* flags to specify defailed behavior
+ * @vmemmap_shift: structural definition of how the vmemmap page metadata
+ * is populated, specifically the metadata page order.
+ * A zero value (default) uses base pages as the vmemmap metadata
+ * representation. A bigger value will set up compound struct pages
+ * of the requested order value.
* @ops: method table
* @owner: an opaque pointer identifying the entity that manages this
* instance. Used by various helpers to make sure that no
@@ -102,6 +107,7 @@ struct dev_pagemap {
struct completion done;
enum memory_type type;
unsigned int flags;
+ unsigned long vmemmap_shift;
const struct dev_pagemap_ops *ops;
void *owner;
int nr_range;
@@ -118,6 +124,11 @@ static inline struct vmem_altmap *pgmap_altmap(struct dev_pagemap *pgmap)
return NULL;
}
+static inline unsigned long pgmap_vmemmap_nr(struct dev_pagemap *pgmap)
+{
+ return 1 << pgmap->vmemmap_shift;
+}
+
#ifdef CONFIG_ZONE_DEVICE
void *memremap_pages(struct dev_pagemap *pgmap, int nid);
void memunmap_pages(struct dev_pagemap *pgmap);