mm/folio: EXPORT_SYMBOL_FOR_KVM(lru_cache_drain_for_folio)

To simplify independent development in the KVM and MM subsystems, now
export to KVM the lru_cache_drain_for_folio() which MM added in 7.3-rc1.

Link: https://lore.kernel.org/lkml/bd6c9c74-e374-a9d3-ba1f-8b6f430894fc@google.com/T/#u
Link: https://lore.kernel.org/02876cea-5727-2ca4-bead-73659ea6fec4@google.com
Signed-off-by: Ackerley Tng <ackerleytng@google.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Suggested-by: David Hildenbrand <david@kernel.org>
Reviewed-by: Fuad Tabba <fuad.tabba@linux.dev>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Sean Christopherson <seanjc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/folio.c

@@ -33,6 +33,7 @@
 #include <linux/page_idle.h>
 #include <linux/local_lock.h>
 #include <linux/buffer_head.h>
+#include <linux/kvm_types.h>
 
 #include "internal.h"
 #include "page_alloc.h"
@@ -926,6 +927,7 @@ void lru_cache_drain_for_folio(const struct folio *folio,
 			*drained = LRU_CACHE_DRAINED_ALL;
 	}
 }
+EXPORT_SYMBOL_FOR_KVM(lru_cache_drain_for_folio);
 
 atomic_t lru_disable_count = ATOMIC_INIT(0);