The AMD architecture for the Frontier supercomputer will
have device memory which can be coherently accessed by
the CPU. The system BIOS advertises this memory as SPM
(special purpose memory) in the UEFI system address map.

The AMDGPU driver needs to be able to lookup this resource
in order to claim it as MEMORY_DEVICE_GENERIC using
devm_memremap_pages.

Signed-off-by: Alex Sierra <redacted>
---
 kernel/resource.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/resource.c b/kernel/resource.c
index 627e61b0c124..269489bb7097 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c

@@ -783,7 +783,7 @@ struct resource *lookup_resource(struct resource *root, resource_size_t start)
 
 	return res;
 }
-
+EXPORT_SYMBOL_GPL(lookup_resource);
 /*
  * Insert a resource into the resource tree. If successful, return NULL,
  * otherwise return the conflicting resource (compare to __request_resource())

-- 
2.17.1