diff --git a/arch/powerpc/perf/hv-gpci.c b/arch/powerpc/perf/hv-gpci.c
index 6884d16ec19b..732cfc53e260 100644
--- a/arch/powerpc/perf/hv-gpci.c
+++ b/arch/powerpc/perf/hv-gpci.c
@@ -164,7 +164,7 @@ static unsigned long single_gpci_request(u32 req, u32 starting_index,
 	 */
 	count = 0;
 	for (i = offset; i < offset + length; i++)
-		count |= arg->bytes[i] << (i - offset);
+		count |= (u64)(arg->bytes[i]) << ((length - 1 - (i - offset)) * 8);
 
 	*value = count;
 out: