mm/memremap: remove unused devmap_managed_key

It's no longer used so remove it.

Link: https://lkml.kernel.org/r/11516e[e-mail]
Signed-off-by: Alistair Popple <[e-mail]>
Reviewed-by: Jason Gunthorpe <[e-mail]>
Acked-by: David Hildenbrand <[e-mail]>
Cc: Balbir Singh <[e-mail]>
Cc: Björn Töpel <[e-mail]>
Cc: Björn Töpel <[e-mail]>
Cc: Christoph Hellwig <[e-mail]>
Cc: Chunyan Zhang <[e-mail]>
Cc: Dan Williams <[e-mail]>
Cc: Deepak Gupta <[e-mail]>
Cc: Gerald Schaefer <[e-mail]>
Cc: Inki Dae <[e-mail]>
Cc: John Groves <[e-mail]>
Cc: John Hubbard <[e-mail]>
Cc: Lorenzo Stoakes <[e-mail]>
Cc: Matthew Wilcox (Oracle) <[e-mail]>
Cc: Will Deacon <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

mm/memremap.c

···
 EXPORT_SYMBOL_GPL(memremap_compat_align);
 #endif
 
-#ifdef CONFIG_FS_DAX
-DEFINE_STATIC_KEY_FALSE(devmap_managed_key);
-EXPORT_SYMBOL(devmap_managed_key);
-
-static void devmap_managed_enable_put(struct dev_pagemap *pgmap)
-{
-	if (pgmap->type == MEMORY_DEVICE_FS_DAX)
-		static_branch_dec(&devmap_managed_key);
-}
-
-static void devmap_managed_enable_get(struct dev_pagemap *pgmap)
-{
-	if (pgmap->type == MEMORY_DEVICE_FS_DAX)
-		static_branch_inc(&devmap_managed_key);
-}
-#else
-static void devmap_managed_enable_get(struct dev_pagemap *pgmap)
-{
-}
-static void devmap_managed_enable_put(struct dev_pagemap *pgmap)
-{
-}
-#endif /* CONFIG_FS_DAX */
-
 static void pgmap_array_delete(struct range *range)
 {
 	xa_store_range(&pgmap_array, PHYS_PFN(range->start), PHYS_PFN(range->end),
···
 	percpu_ref_exit(&pgmap->ref);
 
 	WARN_ONCE(pgmap->altmap.alloc, "failed to free all reserved pages\n");
-	devmap_managed_enable_put(pgmap);
 }
 EXPORT_SYMBOL_GPL(memunmap_pages);
 
···
 				GFP_KERNEL);
 	if (error)
 		return ERR_PTR(error);
-
-	devmap_managed_enable_get(pgmap);
 
 	/*
 	 * Clear the pgmap nr_range as it will be incremented for each