RDMA/hns: Use structs to describe the uABI instead of opencoding

Open coding a loose value is not acceptable for describing the uABI in
RDMA. Provide the missing struct.
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/hns/hns_roce_pd.c

@@ -32,6 +32,7 @@
 
 #include <linux/platform_device.h>
 #include <linux/pci.h>
+#include <uapi/rdma/hns-abi.h>
 #include "hns_roce_device.h"
 
 static int hns_roce_pd_alloc(struct hns_roce_dev *hr_dev, unsigned long *pdn)
@@ -77,7 +78,9 @@ struct ib_pd *hns_roce_alloc_pd(struct ib_device *ib_dev,
 	}
 
 	if (context) {
-		if (ib_copy_to_udata(udata, &pd->pdn, sizeof(u64))) {
+		struct hns_roce_ib_alloc_pd_resp uresp = {.pdn = pd->pdn};
+
+		if (ib_copy_to_udata(udata, &uresp, sizeof(uresp))) {
 			hns_roce_pd_free(to_hr_dev(ib_dev), pd->pdn);
 			dev_err(dev, "[alloc_pd]ib_copy_to_udata failed!\n");
 			kfree(pd);

include/uapi/rdma/hns-abi.h

@@ -63,4 +63,9 @@ struct hns_roce_ib_alloc_ucontext_resp {
 	__u32	qp_tab_size;
 	__u32	reserved;
 };
+
+struct hns_roce_ib_alloc_pd_resp {
+	__u32 pdn;
+};
+
 #endif /* HNS_ABI_USER_H */