net/mlx5: E-Switch, pair only capable devices

OFFLOADS paring using devcom is possible only on devices
that support LAG. Filter based on lag capabilities.

This fixes an issue where mlx5_get_next_phys_dev() was
called without holding the interface lock.

This issue was found when commit
bc4c2f2e ("net/mlx5: Lag, filter non compatible devices")
added an assert that verifies the interface lock is held.

WARNING: CPU: 9 PID: 1706 at drivers/net/ethernet/mellanox/mlx5/core/dev.c:642 mlx5_get_next_phys_dev+0xd2/0x100 [mlx5_core]
Modules linked in: mlx5_vdpa vringh vhost_iotlb vdpa mlx5_ib mlx5_core xt_conntrack xt_MASQUERADE nf_conntrack_netlink nfnetlink xt_addrtype iptable_nat nf_nat br_netfilter rpcrdma rdma_ucm ib_iser libiscsi scsi_transport_iscsi rdma_cm iw_cm ib_umad ib_ipoib ib_cm ib_uverbs ib_core overlay fuse [last unloaded: mlx5_core]
CPU: 9 PID: 1706 Comm: devlink Not tainted 5.18.0-rc7+ #11
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:mlx5_get_next_phys_dev+0xd2/0x100 [mlx5_core]
Code: 02 00 75 48 48 8b 85 80 04 00 00 5d c3 31 c0 5d c3 be ff ff ff ff 48 c7 c7 08 41 5b a0 e8 36 87 28 e3 85 c0 0f 85 6f ff ff ff <0f> 0b e9 68 ff ff ff 48 c7 c7 0c 91 cc 84 e8 cb 36 6f e1 e9 4d ff
RSP: 0018:ffff88811bf47458 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88811b398000 RCX: 0000000000000001
RDX: 0000000080000000 RSI: ffffffffa05b4108 RDI: ffff88812daaaa78
RBP: ffff88812d050380 R08: 0000000000000001 R09: ffff88811d6b3437
R10: 0000000000000001 R11: 00000000fddd3581 R12: ffff88815238c000
R13: ffff88812d050380 R14: ffff8881018aa7e0 R15: ffff88811d6b3428
FS:  00007fc82e18ae80(0000) GS:ffff88842e080000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9630d1b421 CR3: 0000000149802004 CR4: 0000000000370ea0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 mlx5_esw_offloads_devcom_event+0x99/0x3b0 [mlx5_core]
 mlx5_devcom_send_event+0x167/0x1d0 [mlx5_core]
 esw_offloads_enable+0x1153/0x1500 [mlx5_core]
 ? mlx5_esw_offloads_controller_valid+0x170/0x170 [mlx5_core]
 ? wait_for_completion_io_timeout+0x20/0x20
 ? mlx5_rescan_drivers_locked+0x318/0x810 [mlx5_core]
 mlx5_eswitch_enable_locked+0x586/0xc50 [mlx5_core]
 ? mlx5_eswitch_disable_pf_vf_vports+0x1d0/0x1d0 [mlx5_core]
 ? mlx5_esw_try_lock+0x1b/0xb0 [mlx5_core]
 ? mlx5_eswitch_enable+0x270/0x270 [mlx5_core]
 ? __debugfs_create_file+0x260/0x3e0
 mlx5_devlink_eswitch_mode_set+0x27e/0x870 [mlx5_core]
 ? mutex_lock_io_nested+0x12c0/0x12c0
 ? esw_offloads_disable+0x250/0x250 [mlx5_core]
 ? devlink_nl_cmd_trap_get_dumpit+0x470/0x470
 ? rcu_read_lock_sched_held+0x3f/0x70
 devlink_nl_cmd_eswitch_set_doit+0x217/0x620

Fixes: dd3fddb8 ("net/mlx5: E-Switch, handle devcom events only for ports on the same device")
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/dev.c

@@ -579,17 +579,6 @@ static void *pci_get_other_drvdata(struct device *this, struct device *other)
 	return pci_get_drvdata(to_pci_dev(other));
 }
 
-static int next_phys_dev(struct device *dev, const void *data)
-{
-	struct mlx5_core_dev *mdev, *this = (struct mlx5_core_dev *)data;
-
-	mdev = pci_get_other_drvdata(this->device, dev);
-	if (!mdev)
-		return 0;
-
-	return _next_phys_dev(mdev, data);
-}
-
 static int next_phys_dev_lag(struct device *dev, const void *data)
 {
 	struct mlx5_core_dev *mdev, *this = (struct mlx5_core_dev *)data;
@@ -623,13 +612,6 @@ static struct mlx5_core_dev *mlx5_get_next_dev(struct mlx5_core_dev *dev,
 	return pci_get_drvdata(to_pci_dev(next));
 }
 
-/* Must be called with intf_mutex held */
-struct mlx5_core_dev *mlx5_get_next_phys_dev(struct mlx5_core_dev *dev)
-{
-	lockdep_assert_held(&mlx5_intf_mutex);
-	return mlx5_get_next_dev(dev, &next_phys_dev);
-}
-
 /* Must be called with intf_mutex held */
 struct mlx5_core_dev *mlx5_get_next_phys_dev_lag(struct mlx5_core_dev *dev)
 {

drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c

@@ -2690,9 +2690,6 @@ static int mlx5_esw_offloads_devcom_event(int event,
 
 	switch (event) {
 	case ESW_OFFLOADS_DEVCOM_PAIR:
-		if (mlx5_get_next_phys_dev(esw->dev) != peer_esw->dev)
-			break;
-
 		if (mlx5_eswitch_vport_match_metadata_enabled(esw) !=
 		    mlx5_eswitch_vport_match_metadata_enabled(peer_esw))
 			break;
@@ -2744,6 +2741,9 @@ static void esw_offloads_devcom_init(struct mlx5_eswitch *esw)
 	if (!MLX5_CAP_ESW(esw->dev, merged_eswitch))
 		return;
 
+	if (!mlx5_is_lag_supported(esw->dev))
+		return;
+
 	mlx5_devcom_register_component(devcom,
 				       MLX5_DEVCOM_ESW_OFFLOADS,
 				       mlx5_esw_offloads_devcom_event,
@@ -2761,6 +2761,9 @@ static void esw_offloads_devcom_cleanup(struct mlx5_eswitch *esw)
 	if (!MLX5_CAP_ESW(esw->dev, merged_eswitch))
 		return;
 
+	if (!mlx5_is_lag_supported(esw->dev))
+		return;
+
 	mlx5_devcom_send_event(devcom, MLX5_DEVCOM_ESW_OFFLOADS,
 			       ESW_OFFLOADS_DEVCOM_UNPAIR, esw);
 

drivers/net/ethernet/mellanox/mlx5/core/lag/lag.h

@@ -74,6 +74,16 @@ struct mlx5_lag {
 	struct lag_mpesw	  lag_mpesw;
 };
 
+static inline bool mlx5_is_lag_supported(struct mlx5_core_dev *dev)
+{
+	if (!MLX5_CAP_GEN(dev, vport_group_manager) ||
+	    !MLX5_CAP_GEN(dev, lag_master) ||
+	    MLX5_CAP_GEN(dev, num_lag_ports) < 2 ||
+	    MLX5_CAP_GEN(dev, num_lag_ports) > MLX5_MAX_PORTS)
+		return false;
+	return true;
+}
+
 static inline struct mlx5_lag *
 mlx5_lag_dev(struct mlx5_core_dev *dev)
 {

drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h

@@ -209,7 +209,6 @@ int mlx5_attach_device(struct mlx5_core_dev *dev);
 void mlx5_detach_device(struct mlx5_core_dev *dev);
 int mlx5_register_device(struct mlx5_core_dev *dev);
 void mlx5_unregister_device(struct mlx5_core_dev *dev);
-struct mlx5_core_dev *mlx5_get_next_phys_dev(struct mlx5_core_dev *dev);
 struct mlx5_core_dev *mlx5_get_next_phys_dev_lag(struct mlx5_core_dev *dev);
 void mlx5_dev_list_lock(void);
 void mlx5_dev_list_unlock(void);