Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Moshe Shemesh <moshe@mellanox.com>
To:     "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Jiri Pirko <jiri@mellanox.com>
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Moshe Shemesh <moshe@mellanox.com>
Subject: [PATCH net-next RFC v5 02/15] devlink: Add reload action limit level
Date:   Fri, 18 Sep 2020 19:06:38 +0300
Message-Id: <1600445211-31078-3-git-send-email-moshe@mellanox.com>
In-Reply-To: <1600445211-31078-1-git-send-email-moshe@mellanox.com>
References: <1600445211-31078-1-git-send-email-moshe@mellanox.com>
Precedence: bulk

Add reload action limit level to demand restrictions on actions.
Reload action limit levels supported:
none (default): No constrains on actions. Driver implementation may
                include reset or downtime as needed to perform the
                actions.
no_reset: No reset allowed, no down time allowed, no link flap and no
          configuration is lost.

Some combinations of action and limit level are invalid. For example,
driver can not reinitialize its entities without any downtime.

The no_reset limit level will have usecase in this patchset to
implement restricted fw_activate on mlx5.

Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
---
v4 -> v5:
- Remove check DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_MAX
- Added list of invalid action-limit_level combinations and add check to
  supported actions and levels and check user request
v3 -> v4:
- New patch
---
 drivers/net/ethernet/mellanox/mlx4/main.c     |  3 +
 .../net/ethernet/mellanox/mlx5/core/devlink.c |  3 +
 drivers/net/ethernet/mellanox/mlxsw/core.c    |  3 +
 drivers/net/netdevsim/dev.c                   |  6 +-
 include/net/devlink.h                         |  6 +-
 include/uapi/linux/devlink.h                  | 17 +++++
 net/core/devlink.c                            | 76 +++++++++++++++++--
 7 files changed, 107 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c
index 1a482120cc0a..f0ef295af477 100644
--- a/drivers/net/ethernet/mellanox/mlx4/main.c
+++ b/drivers/net/ethernet/mellanox/mlx4/main.c
@@ -3947,6 +3947,7 @@ static int mlx4_restart_one_up(struct pci_dev *pdev, bool reload,
 
 static int mlx4_devlink_reload_down(struct devlink *devlink, bool netns_change,
 				    enum devlink_reload_action action,
+				    enum devlink_reload_action_limit_level limit_level,
 				    struct netlink_ext_ack *extack)
 {
 	struct mlx4_priv *priv = devlink_priv(devlink);
@@ -3964,6 +3965,7 @@ static int mlx4_devlink_reload_down(struct devlink *devlink, bool netns_change,
 }
 
 static int mlx4_devlink_reload_up(struct devlink *devlink, enum devlink_reload_action action,
+				  enum devlink_reload_action_limit_level limit_level,
 				  struct netlink_ext_ack *extack, unsigned long *actions_performed)
 {
 	struct mlx4_priv *priv = devlink_priv(devlink);
@@ -3985,6 +3987,7 @@ static int mlx4_devlink_reload_up(struct devlink *devlink, enum devlink_reload_a
 static const struct devlink_ops mlx4_devlink_ops = {
 	.port_type_set	= mlx4_devlink_port_type_set,
 	.supported_reload_actions = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT),
+	.supported_reload_action_limit_levels = BIT(DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_NONE),
 	.reload_down	= mlx4_devlink_reload_down,
 	.reload_up	= mlx4_devlink_reload_up,
 };
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/devlink.c b/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
index ffc0525cea64..38b00b4a3ce8 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
@@ -90,6 +90,7 @@ mlx5_devlink_info_get(struct devlink *devlink, struct devlink_info_req *req,
 
 static int mlx5_devlink_reload_down(struct devlink *devlink, bool netns_change,
 				    enum devlink_reload_action action,
+				    enum devlink_reload_action_limit_level limit_level,
 				    struct netlink_ext_ack *extack)
 {
 	struct mlx5_core_dev *dev = devlink_priv(devlink);
@@ -99,6 +100,7 @@ static int mlx5_devlink_reload_down(struct devlink *devlink, bool netns_change,
 }
 
 static int mlx5_devlink_reload_up(struct devlink *devlink, enum devlink_reload_action action,
+				  enum devlink_reload_action_limit_level limit_level,
 				  struct netlink_ext_ack *extack, unsigned long *actions_performed)
 {
 	struct mlx5_core_dev *dev = devlink_priv(devlink);
@@ -126,6 +128,7 @@ static const struct devlink_ops mlx5_devlink_ops = {
 	.flash_update = mlx5_devlink_flash_update,
 	.info_get = mlx5_devlink_info_get,
 	.supported_reload_actions = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT),
+	.supported_reload_action_limit_levels = BIT(DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_NONE),
 	.reload_down = mlx5_devlink_reload_down,
 	.reload_up = mlx5_devlink_reload_up,
 };
diff --git a/drivers/net/ethernet/mellanox/mlxsw/core.c b/drivers/net/ethernet/mellanox/mlxsw/core.c
index 19f4486d5faf..fd20b77f70cf 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/core.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/core.c
@@ -1410,6 +1410,7 @@ mlxsw_devlink_info_get(struct devlink *devlink, struct devlink_info_req *req,
 static int
 mlxsw_devlink_core_bus_device_reload_down(struct devlink *devlink,
 					  bool netns_change, enum devlink_reload_action action,
+					  enum devlink_reload_action_limit_level limit_level,
 					  struct netlink_ext_ack *extack)
 {
 	struct mlxsw_core *mlxsw_core = devlink_priv(devlink);
@@ -1423,6 +1424,7 @@ mlxsw_devlink_core_bus_device_reload_down(struct devlink *devlink,
 
 static int
 mlxsw_devlink_core_bus_device_reload_up(struct devlink *devlink, enum devlink_reload_action action,
+					enum devlink_reload_action_limit_level limit_level,
 					struct netlink_ext_ack *extack,
 					unsigned long *actions_performed)
 {
@@ -1570,6 +1572,7 @@ mlxsw_devlink_trap_policer_counter_get(struct devlink *devlink,
 static const struct devlink_ops mlxsw_devlink_ops = {
 	.supported_reload_actions	= BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT) |
 					  BIT(DEVLINK_RELOAD_ACTION_FW_ACTIVATE),
+	.supported_reload_action_limit_levels = BIT(DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_NONE),
 	.reload_down		= mlxsw_devlink_core_bus_device_reload_down,
 	.reload_up		= mlxsw_devlink_core_bus_device_reload_up,
 	.port_type_set			= mlxsw_devlink_port_type_set,
diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c
index 0eb522f6a718..f59af3e85e3a 100644
--- a/drivers/net/netdevsim/dev.c
+++ b/drivers/net/netdevsim/dev.c
@@ -697,7 +697,9 @@ static int nsim_dev_reload_create(struct nsim_dev *nsim_dev,
 static void nsim_dev_reload_destroy(struct nsim_dev *nsim_dev);
 
 static int nsim_dev_reload_down(struct devlink *devlink, bool netns_change,
-				enum devlink_reload_action action, struct netlink_ext_ack *extack)
+				enum devlink_reload_action action,
+				enum devlink_reload_action_limit_level limit_level,
+				struct netlink_ext_ack *extack)
 {
 	struct nsim_dev *nsim_dev = devlink_priv(devlink);
 
@@ -714,6 +716,7 @@ static int nsim_dev_reload_down(struct devlink *devlink, bool netns_change,
 }
 
 static int nsim_dev_reload_up(struct devlink *devlink, enum devlink_reload_action action,
+			      enum devlink_reload_action_limit_level limit_level,
 			      struct netlink_ext_ack *extack, unsigned long *actions_performed)
 {
 	struct nsim_dev *nsim_dev = devlink_priv(devlink);
@@ -882,6 +885,7 @@ nsim_dev_devlink_trap_policer_counter_get(struct devlink *devlink,
 
 static const struct devlink_ops nsim_dev_devlink_ops = {
 	.supported_reload_actions = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT),
+	.supported_reload_action_limit_levels = BIT(DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_NONE),
 	.reload_down = nsim_dev_reload_down,
 	.reload_up = nsim_dev_reload_up,
 	.info_get = nsim_dev_info_get,
diff --git a/include/net/devlink.h b/include/net/devlink.h
index 37abc3e08e9e..d8c62d605381 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -1015,9 +1015,13 @@ enum devlink_trap_group_generic_id {
 
 struct devlink_ops {
 	unsigned long supported_reload_actions;
+	unsigned long supported_reload_action_limit_levels;
 	int (*reload_down)(struct devlink *devlink, bool netns_change,
-			   enum devlink_reload_action action, struct netlink_ext_ack *extack);
+			   enum devlink_reload_action action,
+			   enum devlink_reload_action_limit_level limit_level,
+			   struct netlink_ext_ack *extack);
 	int (*reload_up)(struct devlink *devlink, enum devlink_reload_action action,
+			 enum devlink_reload_action_limit_level limit_level,
 			 struct netlink_ext_ack *extack, unsigned long *actions_performed);
 	int (*port_type_set)(struct devlink_port *devlink_port,
 			     enum devlink_port_type port_type);
diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index fdba7ab58a79..0c5d942dcbd5 100644
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -289,6 +289,22 @@ enum devlink_reload_action {
 	DEVLINK_RELOAD_ACTION_MAX = __DEVLINK_RELOAD_ACTION_MAX - 1
 };
 
+/**
+ * enum devlink_reload_action_limit_level - Reload action limit level.
+ * @DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_NONE: No constrains on action. Action may include
+ *                                          reset or downtime as needed.
+ * @DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_NO_RESET: No reset allowed, no down time allowed,
+ *                                              no link flap and no configuration is lost.
+ */
+enum devlink_reload_action_limit_level {
+	DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_NONE,
+	DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_NO_RESET,
+
+	/* Add new reload actions limit level above */
+	__DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_MAX,
+	DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_MAX = __DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_MAX - 1
+};
+
 enum devlink_attr {
 	/* don't change the order or add anything between, this is ABI! */
 	DEVLINK_ATTR_UNSPEC,
@@ -480,6 +496,7 @@ enum devlink_attr {
 
 	DEVLINK_ATTR_RELOAD_ACTION,		/* u8 */
 	DEVLINK_ATTR_RELOAD_ACTIONS_PERFORMED,	/* nested */
+	DEVLINK_ATTR_RELOAD_ACTION_LIMIT_LEVEL,	/* u8 */
 
 	/* add new attributes above here, update the policy in devlink.c */
 
diff --git a/net/core/devlink.c b/net/core/devlink.c
index 318ef29f81f2..fee6fcc7dead 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -462,12 +462,45 @@ static int devlink_nl_put_handle(struct sk_buff *msg, struct devlink *devlink)
 	return 0;
 }
 
+struct devlink_reload_combination {
+	enum devlink_reload_action action;
+	enum devlink_reload_action_limit_level limit_level;
+};
+
+static const struct devlink_reload_combination devlink_reload_invalid_combinations[] = {
+	{
+		/* can't reinitialize driver with no down time */
+		.action = DEVLINK_RELOAD_ACTION_DRIVER_REINIT,
+		.limit_level = DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_NO_RESET,
+	},
+};
+
+static bool
+devlink_reload_combination_is_invalid(enum devlink_reload_action action,
+				      enum devlink_reload_action_limit_level limit_level)
+{
+	int i;
+
+	for (i = 0 ; i <  ARRAY_SIZE(devlink_reload_invalid_combinations) ; i++)
+		if (devlink_reload_invalid_combinations[i].action == action &&
+		    devlink_reload_invalid_combinations[i].limit_level == limit_level)
+			return true;
+	return false;
+}
+
 static bool
 devlink_reload_action_is_supported(struct devlink *devlink, enum devlink_reload_action action)
 {
 	return test_bit(action, &devlink->ops->supported_reload_actions);
 }
 
+static bool
+devlink_reload_action_limit_level_is_supported(struct devlink *devlink,
+					       enum devlink_reload_action_limit_level limit_level)
+{
+	return test_bit(limit_level, &devlink->ops->supported_reload_action_limit_levels);
+}
+
 static int devlink_nl_fill(struct sk_buff *msg, struct devlink *devlink,
 			   enum devlink_command cmd, u32 portid,
 			   u32 seq, int flags)
@@ -2975,22 +3008,23 @@ bool devlink_is_reload_failed(const struct devlink *devlink)
 EXPORT_SYMBOL_GPL(devlink_is_reload_failed);
 
 static int devlink_reload(struct devlink *devlink, struct net *dest_net,
-			  enum devlink_reload_action action, struct netlink_ext_ack *extack,
-			  unsigned long *actions_performed)
+			  enum devlink_reload_action action,
+			  enum devlink_reload_action_limit_level limit_level,
+			  struct netlink_ext_ack *extack, unsigned long *actions_performed)
 {
 	int err;
 
 	if (!devlink->reload_enabled)
 		return -EOPNOTSUPP;
 
-	err = devlink->ops->reload_down(devlink, !!dest_net, action, extack);
+	err = devlink->ops->reload_down(devlink, !!dest_net, action, limit_level, extack);
 	if (err)
 		return err;
 
 	if (dest_net && !net_eq(dest_net, devlink_net(devlink)))
 		devlink_reload_netns_change(devlink, dest_net);
 
-	err = devlink->ops->reload_up(devlink, action, extack, actions_performed);
+	err = devlink->ops->reload_up(devlink, action, limit_level, extack, actions_performed);
 	devlink_reload_failed_set(devlink, !!err);
 	if (err)
 		return err;
@@ -3040,6 +3074,7 @@ devlink_nl_reload_actions_performed_fill(struct sk_buff *msg,
 
 static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info)
 {
+	enum devlink_reload_action_limit_level limit_level;
 	struct devlink *devlink = info->user_ptr[0];
 	enum devlink_reload_action action;
 	unsigned long actions_performed;
@@ -3077,7 +3112,21 @@ static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info)
 		return -EOPNOTSUPP;
 	}
 
-	err = devlink_reload(devlink, dest_net, action, info->extack, &actions_performed);
+	if (info->attrs[DEVLINK_ATTR_RELOAD_ACTION_LIMIT_LEVEL])
+		limit_level = nla_get_u8(info->attrs[DEVLINK_ATTR_RELOAD_ACTION_LIMIT_LEVEL]);
+	else
+		limit_level = DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_NONE;
+
+	if (!devlink_reload_action_limit_level_is_supported(devlink, limit_level)) {
+		NL_SET_ERR_MSG_MOD(info->extack, "Requested limit level is not supported by the driver");
+		return -EOPNOTSUPP;
+	}
+	if (devlink_reload_combination_is_invalid(action, limit_level)) {
+		NL_SET_ERR_MSG_MOD(info->extack, "Requested limit level is invalid for this action");
+		return -EINVAL;
+	}
+	err = devlink_reload(devlink, dest_net, action, limit_level, info->extack,
+			     &actions_performed);
 
 	if (dest_net)
 		put_net(dest_net);
@@ -7154,6 +7203,7 @@ static const struct nla_policy devlink_nl_policy[DEVLINK_ATTR_MAX + 1] = {
 	[DEVLINK_ATTR_TRAP_POLICER_BURST] = { .type = NLA_U64 },
 	[DEVLINK_ATTR_PORT_FUNCTION] = { .type = NLA_NESTED },
 	[DEVLINK_ATTR_RELOAD_ACTION] = { .type = NLA_U8 },
+	[DEVLINK_ATTR_RELOAD_ACTION_LIMIT_LEVEL] = { .type = NLA_U8 },
 };
 
 static const struct genl_ops devlink_nl_ops[] = {
@@ -7489,6 +7539,9 @@ static struct genl_family devlink_nl_family __ro_after_init = {
 
 static bool devlink_reload_actions_valid(const struct devlink_ops *ops)
 {
+	const struct devlink_reload_combination *comb;
+	int i;
+
 	if (!devlink_reload_supported(ops)) {
 		if (WARN_ON(ops->supported_reload_actions))
 			return false;
@@ -7498,6 +7551,18 @@ static bool devlink_reload_actions_valid(const struct devlink_ops *ops)
 	if (WARN_ON(ops->supported_reload_actions >= BIT(__DEVLINK_RELOAD_ACTION_MAX) ||
 		    ops->supported_reload_actions <= BIT(DEVLINK_RELOAD_ACTION_UNSPEC)))
 		return false;
+
+	if (WARN_ON(!ops->supported_reload_action_limit_levels ||
+		    ops->supported_reload_action_limit_levels >=
+		    BIT(__DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_MAX)))
+		return false;
+
+	for (i = 0; i <  ARRAY_SIZE(devlink_reload_invalid_combinations); i++)  {
+		comb = &devlink_reload_invalid_combinations[i];
+		if (ops->supported_reload_actions == BIT(comb->action) &&
+		    ops->supported_reload_action_limit_levels == BIT(comb->limit_level))
+			return false;
+	}
 	return true;
 }
 
@@ -9793,6 +9858,7 @@ static void __net_exit devlink_pernet_pre_exit(struct net *net)
 				continue;
 			err = devlink_reload(devlink, &init_net,
 					     DEVLINK_RELOAD_ACTION_DRIVER_REINIT,
+					     DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_NONE,
 					     NULL, &actions_performed);
 			if (err && err != -EOPNOTSUPP)
 				pr_warn("Failed to reload devlink instance into init_net\n");
-- 
2.17.1