acpi,memhotplug: enable MHP_MEMMAP_ON_MEMORY when supported

Let the caller check whether it can pass MHP_MEMMAP_ON_MEMORY by
checking mhp_supports_memmap_on_memory().  MHP_MEMMAP_ON_MEMORY can only
be set in case ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE is enabled, the
architecture supports altmap, and the range to be added spans a single
memory block.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Oscar Salvador <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Pavel Tatashin <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Author: osalvadorvilardaga

drivers/acpi/acpi_memhotplug.c

@@ -171,6 +171,7 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 	acpi_handle handle = mem_device->device->handle;
 	int result, num_enabled = 0;
 	struct acpi_memory_info *info;
+	mhp_t mhp_flags = MHP_NONE;
 	int node;
 
 	node = acpi_get_node(handle);
@@ -194,8 +195,10 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 		if (node < 0)
 			node = memory_add_physaddr_to_nid(info->start_addr);
 
+		if (mhp_supports_memmap_on_memory(info->length))
+			mhp_flags |= MHP_MEMMAP_ON_MEMORY;
 		result = __add_memory(node, info->start_addr, info->length,
-				      MHP_NONE);
+				      mhp_flags);
 
 		/*
 		 * If the memory block has been used by the kernel, add_memory()