IB/mlx4: Add support for XRC QPs

Support the creation of XRC INI and TGT QPs.  To handle the case where
a CQ or PD is not provided, we allocate them internally with the xrcd.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/infiniband/hw/mlx4/main.c

@@ -128,6 +128,8 @@ static int mlx4_ib_query_device(struct ib_device *ibdev,
 	    (dev->dev->caps.bmme_flags & MLX4_BMME_FLAG_REMOTE_INV) &&
 	    (dev->dev->caps.bmme_flags & MLX4_BMME_FLAG_FAST_REG_WR))
 		props->device_cap_flags |= IB_DEVICE_MEM_MGT_EXTENSIONS;
+	if (dev->dev->caps.flags & MLX4_DEV_CAP_FLAG_XRC)
+		props->device_cap_flags |= IB_DEVICE_XRC;
 
 	props->vendor_id	   = be32_to_cpup((__be32 *) (out_mad->data + 36)) &
 		0xffffff;

drivers/infiniband/hw/mlx4/mlx4_ib.h

@@ -145,6 +145,7 @@ struct mlx4_ib_qp {
 	struct mlx4_mtt		mtt;
 	int			buf_size;
 	struct mutex		mutex;
+	u16			xrcdn;
 	u32			flags;
 	u8			port;
 	u8			alt_port;

drivers/net/mlx4/qp.c

@@ -280,6 +280,9 @@ int mlx4_init_qp_table(struct mlx4_dev *dev)
 	 * We reserve 2 extra QPs per port for the special QPs.  The
 	 * block of special QPs must be aligned to a multiple of 8, so
 	 * round up.
+	 *
+	 * We also reserve the MSB of the 24-bit QP number to indicate
+	 * that a QP is an XRC QP.
 	 */
 	dev->caps.sqp_start =
 		ALIGN(dev->caps.reserved_qps_cnt[MLX4_QP_REGION_FW], 8);

include/linux/mlx4/qp.h

@@ -75,6 +75,7 @@ enum {
 	MLX4_QP_ST_UC				= 0x1,
 	MLX4_QP_ST_RD				= 0x2,
 	MLX4_QP_ST_UD				= 0x3,
+	MLX4_QP_ST_XRC				= 0x6,
 	MLX4_QP_ST_MLX				= 0x7
 };
 
@@ -137,7 +138,7 @@ struct mlx4_qp_context {
 	__be32			ssn;
 	__be32			params2;
 	__be32			rnr_nextrecvpsn;
-	__be32			srcd;
+	__be32			xrcd;
 	__be32			cqn_recv;
 	__be64			db_rec_addr;
 	__be32			qkey;