IB/hns: Optimize the logic of allocating memory using APIs

This patch modified the logic of allocating memory using APIs in
hns RoCE driver. We used kcalloc instead of kmalloc_array and
bitmap_zero. And When kcalloc failed, call vzalloc to alloc
memory.
Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>
Signed-off-by: Ping Zhang <zhangping5@huawei.com>
Signed-off-by: Salil Mehta  <salil.mehta@huawei.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/hns/hns_roce_mr.c

@@ -137,11 +137,13 @@ static int hns_roce_buddy_init(struct hns_roce_buddy *buddy, int max_order)
 
 	for (i = 0; i <= buddy->max_order; ++i) {
 		s = BITS_TO_LONGS(1 << (buddy->max_order - i));
-		buddy->bits[i] = kmalloc_array(s, sizeof(long), GFP_KERNEL);
+		buddy->bits[i] = kcalloc(s, sizeof(long), GFP_KERNEL |
+					 __GFP_NOWARN);
+		if (!buddy->bits[i]) {
+			buddy->bits[i] = vzalloc(s * sizeof(long));
 			if (!buddy->bits[i])
 				goto err_out_free;
-
-		bitmap_zero(buddy->bits[i], 1 << (buddy->max_order - i));
+		}
 	}
 
 	set_bit(0, buddy->bits[buddy->max_order]);
@@ -151,7 +153,7 @@ static int hns_roce_buddy_init(struct hns_roce_buddy *buddy, int max_order)
 
 err_out_free:
 	for (i = 0; i <= buddy->max_order; ++i)
-		kfree(buddy->bits[i]);
+		kvfree(buddy->bits[i]);
 
 err_out:
 	kfree(buddy->bits);
@@ -164,7 +166,7 @@ static void hns_roce_buddy_cleanup(struct hns_roce_buddy *buddy)
 	int i;
 
 	for (i = 0; i <= buddy->max_order; ++i)
-		kfree(buddy->bits[i]);
+		kvfree(buddy->bits[i]);
 
 	kfree(buddy->bits);
 	kfree(buddy->num_free);