mlx4_core: Adjustments to Flow Steering activation logic for SR-IOV

Separate flow steering capability detection from the decision to activate.

For the master (and for native), detect the flow steering capability
in mlx4_dev_cap, but activate the appropriate steering type in a new
function choose_flow_steering() based on detected data.

For VFs, activate flow steering based on what was actually activated
by the master, where that info is obtained via QUERY_HCA. This fixes
the current VF detection which is wrongly based on QUERY_DEV_CAP.

Also, for SR-IOV mode, if flow steering may be activated, do so only
if the max number of QPs per rule is sufficient to satisfy one
subscription per VF.  If not, fall back to B0 mode. This is needed to
serve registrations done by L2 network drivers such as mlx4_en and
IPoIB when the network stack attempts to join to multicast groups such
as all-hosts or the IPoIB broadcast group.

Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/net/ethernet/mellanox/mlx4/fw.c

@@ -1338,6 +1338,7 @@ int mlx4_QUERY_HCA(struct mlx4_dev *dev,
 {
 	struct mlx4_cmd_mailbox *mailbox;
 	__be32 *outbox;
+	u32 dword_field;
 	int err;
 	u8 byte_field;
 
@@ -1372,10 +1373,18 @@ int mlx4_QUERY_HCA(struct mlx4_dev *dev,
 	MLX4_GET(param->rdmarc_base,   outbox, INIT_HCA_RDMARC_BASE_OFFSET);
 	MLX4_GET(param->log_rd_per_qp, outbox, INIT_HCA_LOG_RD_OFFSET);
 
+	MLX4_GET(dword_field, outbox, INIT_HCA_FLAGS_OFFSET);
+	if (dword_field & (1 << INIT_HCA_DEVICE_MANAGED_FLOW_STEERING_EN)) {
+		param->steering_mode = MLX4_STEERING_MODE_DEVICE_MANAGED;
+	} else {
+		MLX4_GET(byte_field, outbox, INIT_HCA_UC_STEERING_OFFSET);
+		if (byte_field & 0x8)
+			param->steering_mode = MLX4_STEERING_MODE_B0;
+		else
+			param->steering_mode = MLX4_STEERING_MODE_A0;
+	}
 	/* steering attributes */
-	if (dev->caps.steering_mode ==
-	    MLX4_STEERING_MODE_DEVICE_MANAGED) {
-
+	if (param->steering_mode == MLX4_STEERING_MODE_DEVICE_MANAGED) {
 		MLX4_GET(param->mc_base, outbox, INIT_HCA_FS_BASE_OFFSET);
 		MLX4_GET(param->log_mc_entry_sz, outbox,
 			 INIT_HCA_FS_LOG_ENTRY_SZ_OFFSET);

drivers/net/ethernet/mellanox/mlx4/fw.h

@@ -172,6 +172,7 @@ struct mlx4_init_hca_param {
 	u8  log_uar_sz;
 	u8  uar_page_sz; /* log pg sz in 4k chunks */
 	u8  fs_hash_enable_bits;
+	u8  steering_mode; /* for QUERY_HCA */
 	u64 dev_cap_enabled;
 };
 

drivers/net/ethernet/mellanox/mlx4/main.c

@@ -281,28 +281,6 @@ static int mlx4_dev_cap(struct mlx4_dev *dev, struct mlx4_dev_cap *dev_cap)
 	dev->caps.max_gso_sz	     = dev_cap->max_gso_sz;
 	dev->caps.max_rss_tbl_sz     = dev_cap->max_rss_tbl_sz;
 
-	if (dev_cap->flags2 & MLX4_DEV_CAP_FLAG2_FS_EN) {
-		dev->caps.steering_mode = MLX4_STEERING_MODE_DEVICE_MANAGED;
-		dev->caps.num_qp_per_mgm = dev_cap->fs_max_num_qp_per_entry;
-		dev->caps.fs_log_max_ucast_qp_range_size =
-			dev_cap->fs_log_max_ucast_qp_range_size;
-	} else {
-		if (dev->caps.flags & MLX4_DEV_CAP_FLAG_VEP_UC_STEER &&
-		    dev->caps.flags & MLX4_DEV_CAP_FLAG_VEP_MC_STEER) {
-			dev->caps.steering_mode = MLX4_STEERING_MODE_B0;
-		} else {
-			dev->caps.steering_mode = MLX4_STEERING_MODE_A0;
-
-			if (dev->caps.flags & MLX4_DEV_CAP_FLAG_VEP_UC_STEER ||
-			    dev->caps.flags & MLX4_DEV_CAP_FLAG_VEP_MC_STEER)
-				mlx4_warn(dev, "Must have UC_STEER and MC_STEER flags "
-						"set to use B0 steering. Falling back to A0 steering mode.\n");
-		}
-		dev->caps.num_qp_per_mgm = mlx4_get_qp_per_mgm(dev);
-	}
-	mlx4_dbg(dev, "Steering mode is: %s\n",
-		 mlx4_steering_mode_str(dev->caps.steering_mode));
-
 	/* Sense port always allowed on supported devices for ConnectX-1 and -2 */
 	if (mlx4_priv(dev)->pci_dev_data & MLX4_PCI_DEV_FORCE_SENSE_PORT)
 		dev->caps.flags |= MLX4_DEV_CAP_FLAG_SENSE_SUPPORT;
@@ -493,6 +471,23 @@ int mlx4_is_slave_active(struct mlx4_dev *dev, int slave)
 }
 EXPORT_SYMBOL(mlx4_is_slave_active);
 
+static void slave_adjust_steering_mode(struct mlx4_dev *dev,
+				       struct mlx4_dev_cap *dev_cap,
+				       struct mlx4_init_hca_param *hca_param)
+{
+	dev->caps.steering_mode = hca_param->steering_mode;
+	if (dev->caps.steering_mode == MLX4_STEERING_MODE_DEVICE_MANAGED) {
+		dev->caps.num_qp_per_mgm = dev_cap->fs_max_num_qp_per_entry;
+		dev->caps.fs_log_max_ucast_qp_range_size =
+			dev_cap->fs_log_max_ucast_qp_range_size;
+	} else
+		dev->caps.num_qp_per_mgm =
+			4 * ((1 << hca_param->log_mc_entry_sz)/16 - 2);
+
+	mlx4_dbg(dev, "Steering mode is: %s\n",
+		 mlx4_steering_mode_str(dev->caps.steering_mode));
+}
+
 static int mlx4_slave_cap(struct mlx4_dev *dev)
 {
 	int			   err;
@@ -635,6 +630,8 @@ static int mlx4_slave_cap(struct mlx4_dev *dev)
 		dev->caps.cqe_size   = 32;
 	}
 
+	slave_adjust_steering_mode(dev, &dev_cap, &hca_param);
+
 	return 0;
 
 err_mem:
@@ -1321,6 +1318,34 @@ static void mlx4_parav_master_pf_caps(struct mlx4_dev *dev)
 	}
 }
 
+static void choose_steering_mode(struct mlx4_dev *dev,
+				 struct mlx4_dev_cap *dev_cap)
+{
+	if (dev_cap->flags2 & MLX4_DEV_CAP_FLAG2_FS_EN &&
+	    (!mlx4_is_mfunc(dev) ||
+	     (dev_cap->fs_max_num_qp_per_entry >= (num_vfs + 1)))) {
+		dev->caps.steering_mode = MLX4_STEERING_MODE_DEVICE_MANAGED;
+		dev->caps.num_qp_per_mgm = dev_cap->fs_max_num_qp_per_entry;
+		dev->caps.fs_log_max_ucast_qp_range_size =
+			dev_cap->fs_log_max_ucast_qp_range_size;
+	} else {
+		if (dev->caps.flags & MLX4_DEV_CAP_FLAG_VEP_UC_STEER &&
+		    dev->caps.flags & MLX4_DEV_CAP_FLAG_VEP_MC_STEER)
+			dev->caps.steering_mode = MLX4_STEERING_MODE_B0;
+		else {
+			dev->caps.steering_mode = MLX4_STEERING_MODE_A0;
+
+			if (dev->caps.flags & MLX4_DEV_CAP_FLAG_VEP_UC_STEER ||
+			    dev->caps.flags & MLX4_DEV_CAP_FLAG_VEP_MC_STEER)
+				mlx4_warn(dev, "Must have both UC_STEER and MC_STEER flags "
+					  "set to use B0 steering. Falling back to A0 steering mode.\n");
+		}
+		dev->caps.num_qp_per_mgm = mlx4_get_qp_per_mgm(dev);
+	}
+	mlx4_dbg(dev, "Steering mode is: %s\n",
+		 mlx4_steering_mode_str(dev->caps.steering_mode));
+}
+
 static int mlx4_init_hca(struct mlx4_dev *dev)
 {
 	struct mlx4_priv	  *priv = mlx4_priv(dev);
@@ -1360,6 +1385,8 @@ static int mlx4_init_hca(struct mlx4_dev *dev)
 			goto err_stop_fw;
 		}
 
+		choose_steering_mode(dev, &dev_cap);
+
 		if (mlx4_is_master(dev))
 			mlx4_parav_master_pf_caps(dev);