diff --git a/arch/powerpc/sysdev/dcr.c b/arch/powerpc/sysdev/dcr.c
index dffeeaeca1d938ea9ef740d9d5be5a114b336f0f..1fc5819e7d18d595b7f37e364ce9b52e8efe9591 100644
--- a/arch/powerpc/sysdev/dcr.c
+++ b/arch/powerpc/sysdev/dcr.c
@@ -129,7 +129,7 @@ void dcr_unmap(dcr_host_t host, unsigned int dcr_n, unsigned int dcr_c)
 
 	if (h.token == NULL)
 		return;
-	h.token -= dcr_n * h.stride;
+	h.token += dcr_n * h.stride;
 	iounmap(h.token);
 	h.token = NULL;
 }