ice: support basic E-Switch mode control

Write set and get eswitch mode functions used by devlink
ops. Use new pf struct member eswitch_mode to track current
eswitch mode in driver.

Changing eswitch mode is only allowed when there are no
VFs created.

Create new file for eswitch related code.

Add config flag ICE_SWITCHDEV to allow user to choose if
switchdev support should be enabled or disabled.

Use case examples:
- show current eswitch mode ('legacy' is the default one)
[root@localhost]# devlink dev eswitch show pci/0000:03:00.1
pci/0000:03:00.1: mode legacy

- move to 'switchdev' mode
[root@localhost]# devlink dev eswitch set pci/0000:03:00.1 mode
switchdev
[root@localhost]# devlink dev eswitch show pci/0000:03:00.1
pci/0000:03:00.1: mode switchdev

- create 2 VFs
[root@localhost]# echo 2 > /sys/class/net/ens4f1/device/sriov_numvfs

- unsuccessful attempt to change eswitch mode while VFs are created
[root@localhost]# devlink dev eswitch set pci/0000:03:00.1 mode legacy
devlink answers: Operation not supported

- destroy VFs
[root@localhost]# echo 0 > /sys/class/net/ens4f1/device/sriov_numvfs

- restore 'legacy' mode
[root@localhost]# devlink dev eswitch set pci/0000:03:00.1 mode legacy
[root@localhost]# devlink dev eswitch show pci/0000:03:00.1
pci/0000:03:00.1: mode legacy

Co-developed-by: Grzegorz Nitka <grzegorz.nitka@intel.com>
Signed-off-by: Grzegorz Nitka <grzegorz.nitka@intel.com>
Signed-off-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Tested-by: Sandeep Penigalapati <sandeep.penigalapati@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/ice/ice_eswitch.h b/drivers/net/ethernet/intel/ice/ice_eswitch.h
new file mode 100644
index 000000000000..1964b060562a
--- /dev/null
+++ b/drivers/net/ethernet/intel/ice/ice_eswitch.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2019-2021, Intel Corporation. */
+
+#ifndef _ICE_ESWITCH_H_
+#define _ICE_ESWITCH_H_
+
+#include <net/devlink.h>
+
+#ifdef CONFIG_ICE_SWITCHDEV
+int ice_eswitch_mode_get(struct devlink *devlink, u16 *mode);
+int
+ice_eswitch_mode_set(struct devlink *devlink, u16 mode,
+		     struct netlink_ext_ack *extack);
+bool ice_is_eswitch_mode_switchdev(struct ice_pf *pf);
+#else /* CONFIG_ICE_SWITCHDEV */
+static inline int
+ice_eswitch_mode_get(struct devlink *devlink, u16 *mode)
+{
+	return DEVLINK_ESWITCH_MODE_LEGACY;
+}
+
+static inline int
+ice_eswitch_mode_set(struct devlink *devlink, u16 mode,
+		     struct netlink_ext_ack *extack)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline bool
+ice_is_eswitch_mode_switchdev(struct ice_pf *pf)
+{
+	return false;
+}
+#endif /* CONFIG_ICE_SWITCHDEV */
+#endif /* _ICE_ESWITCH_H_ */