diff --git a/drivers/infiniband/hw/mlx5/mem.c b/drivers/infiniband/hw/mlx5/mem.c
index 40df2cca0609..996b54e366b0 100644
--- a/drivers/infiniband/hw/mlx5/mem.c
+++ b/drivers/infiniband/hw/mlx5/mem.c
@@ -71,7 +71,7 @@ void mlx5_ib_cont_pages(struct ib_umem *umem, u64 addr, int *count, int *shift,
 
 	addr = addr >> page_shift;
 	tmp = (unsigned long)addr;
-	m = find_first_bit(&tmp, sizeof(tmp));
+	m = find_first_bit(&tmp, BITS_PER_LONG);
 	skip = 1 << m;
 	mask = skip - 1;
 	i = 0;
@@ -81,7 +81,7 @@ void mlx5_ib_cont_pages(struct ib_umem *umem, u64 addr, int *count, int *shift,
 		for (k = 0; k < len; k++) {
 			if (!(i & mask)) {
 				tmp = (unsigned long)pfn;
-				m = min_t(unsigned long, m, find_first_bit(&tmp, sizeof(tmp)));
+				m = min_t(unsigned long, m, find_first_bit(&tmp, BITS_PER_LONG));
 				skip = 1 << m;
 				mask = skip - 1;
 				base = pfn;
@@ -89,7 +89,7 @@ void mlx5_ib_cont_pages(struct ib_umem *umem, u64 addr, int *count, int *shift,
 			} else {
 				if (base + p != pfn) {
 					tmp = (unsigned long)p;
-					m = find_first_bit(&tmp, sizeof(tmp));
+					m = find_first_bit(&tmp, BITS_PER_LONG);
 					skip = 1 << m;
 					mask = skip - 1;
 					base = pfn;