mm/ZONE_DEVICE/devmem_pages_remove: allow early removal of device memory

HMM wants to remove device memory early before device tear down so add an
helper to do that.

Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index 469c88d4c0ee..b6f03e989f92 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -60,6 +60,7 @@ void *devm_memremap_pages(struct device *dev, struct resource *res,
 			  struct percpu_ref *ref, struct vmem_altmap *altmap,
 			  struct dev_pagemap **ppgmap, int flags);
 struct dev_pagemap *find_dev_pagemap(resource_size_t phys);
+int devm_memremap_pages_remove(struct device *dev, struct dev_pagemap *pgmap);
 
 static inline bool is_addressable_page(const struct page *page)
 {
@@ -88,6 +89,12 @@ static inline struct dev_pagemap *find_dev_pagemap(resource_size_t phys)
 	return NULL;
 }
 
+static inline int devm_memremap_pages_remove(struct device *dev,
+					     struct dev_pagemap *pgmap)
+{
+	return -EINVAL;
+}
+
 static inline bool is_addressable_page(const struct page *page)
 {
 	return true;