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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 v4 01/15] devlink: Add reload action option to devlink reload command
Date:   Mon, 14 Sep 2020 09:07:48 +0300
Message-Id: <1600063682-17313-2-git-send-email-moshe@mellanox.com>
In-Reply-To: <1600063682-17313-1-git-send-email-moshe@mellanox.com>
References: <1600063682-17313-1-git-send-email-moshe@mellanox.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Add devlink reload action to allow the user to request a specific reload
action. The action parameter is optional, if not specified then devlink
driver re-init action is used (backward compatible).
Note that when required to do firmware activation some drivers may need
to reload the driver. On the other hand some drivers may need to reset
the firmware to reinitialize the driver entities. Therefore, the devlink
reload command returns the actions which were actually performed.
Reload actions supported are:
driver_reinit: driver entities re-initialization, applying devlink-param
               and devlink-resource values.
fw_activate: firmware activate.

command examples:
$devlink dev reload pci/0000:82:00.0 action driver_reinit
reload_actions_performed:
  driver_reinit

$devlink dev reload pci/0000:82:00.0 action fw_activate
reload_actions_performed:
  driver_reinit fw_activate

Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
---
v3 -> v4:
- Removed fw_activate_no_reset as an action (next patch adds limit
  levels instead).
- Renamed actions_done to actions_performed
v2 -> v3:
- Replace fw_live_patch action by fw_activate_no_reset
- Devlink reload returns the actions done over netlink reply
v1 -> v2:
- Instead of reload levels driver,fw_reset,fw_live_patch have reload
  actions driver_reinit,fw_activate,fw_live_patch
- Remove driver default level, the action driver_reinit is the default
  action for all drivers
---
 drivers/net/ethernet/mellanox/mlx4/main.c     |  14 ++-
 .../net/ethernet/mellanox/mlx5/core/devlink.c |  15 ++-
 drivers/net/ethernet/mellanox/mlxsw/core.c    |  25 ++--
 drivers/net/netdevsim/dev.c                   |  16 ++-
 include/net/devlink.h                         |   7 +-
 include/uapi/linux/devlink.h                  |  19 +++
 net/core/devlink.c                            | 111 +++++++++++++++++-
 7 files changed, 180 insertions(+), 27 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c
index 70cf24ba71e4..aadf1676a0ed 100644
--- a/drivers/net/ethernet/mellanox/mlx4/main.c
+++ b/drivers/net/ethernet/mellanox/mlx4/main.c
@@ -3946,6 +3946,7 @@ static int mlx4_restart_one_up(struct pci_dev *pdev, bool reload,
 			       struct devlink *devlink);
 
 static int mlx4_devlink_reload_down(struct devlink *devlink, bool netns_change,
+				    enum devlink_reload_action action,
 				    struct netlink_ext_ack *extack)
 {
 	struct mlx4_priv *priv = devlink_priv(devlink);
@@ -3962,8 +3963,8 @@ static int mlx4_devlink_reload_down(struct devlink *devlink, bool netns_change,
 	return 0;
 }
 
-static int mlx4_devlink_reload_up(struct devlink *devlink,
-				  struct netlink_ext_ack *extack)
+static int mlx4_devlink_reload_up(struct devlink *devlink, enum devlink_reload_action action,
+				  struct netlink_ext_ack *extack, unsigned long *actions_performed)
 {
 	struct mlx4_priv *priv = devlink_priv(devlink);
 	struct mlx4_dev *dev = &priv->dev;
@@ -3971,15 +3972,20 @@ static int mlx4_devlink_reload_up(struct devlink *devlink,
 	int err;
 
 	err = mlx4_restart_one_up(persist->pdev, true, devlink);
-	if (err)
+	if (err) {
 		mlx4_err(persist->dev, "mlx4_restart_one_up failed, ret=%d\n",
 			 err);
+		return err;
+	}
+	if (actions_performed)
+		*actions_performed = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT);
 
-	return err;
+	return 0;
 }
 
 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),
 	.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 c709e9a385f6..9cd6b6c884e3 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
@@ -89,6 +89,7 @@ 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,
 				    struct netlink_ext_ack *extack)
 {
 	struct mlx5_core_dev *dev = devlink_priv(devlink);
@@ -97,12 +98,19 @@ static int mlx5_devlink_reload_down(struct devlink *devlink, bool netns_change,
 	return 0;
 }
 
-static int mlx5_devlink_reload_up(struct devlink *devlink,
-				  struct netlink_ext_ack *extack)
+static int mlx5_devlink_reload_up(struct devlink *devlink, enum devlink_reload_action action,
+				  struct netlink_ext_ack *extack, unsigned long *actions_performed)
 {
 	struct mlx5_core_dev *dev = devlink_priv(devlink);
+	int err;
 
-	return mlx5_load_one(dev, false);
+	err = mlx5_load_one(dev, false);
+	if (err)
+		return err;
+	if (actions_performed)
+		*actions_performed = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT);
+
+	return 0;
 }
 
 static const struct devlink_ops mlx5_devlink_ops = {
@@ -118,6 +126,7 @@ static const struct devlink_ops mlx5_devlink_ops = {
 #endif
 	.flash_update = mlx5_devlink_flash_update,
 	.info_get = mlx5_devlink_info_get,
+	.supported_reload_actions = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT),
 	.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 ec45a03140d7..c0a32f685b85 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/core.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/core.c
@@ -1113,7 +1113,7 @@ 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,
+					  bool netns_change, enum devlink_reload_action action,
 					  struct netlink_ext_ack *extack)
 {
 	struct mlxsw_core *mlxsw_core = devlink_priv(devlink);
@@ -1126,15 +1126,24 @@ mlxsw_devlink_core_bus_device_reload_down(struct devlink *devlink,
 }
 
 static int
-mlxsw_devlink_core_bus_device_reload_up(struct devlink *devlink,
-					struct netlink_ext_ack *extack)
+mlxsw_devlink_core_bus_device_reload_up(struct devlink *devlink, enum devlink_reload_action action,
+					struct netlink_ext_ack *extack,
+					unsigned long *actions_performed)
 {
 	struct mlxsw_core *mlxsw_core = devlink_priv(devlink);
+	int err;
 
-	return mlxsw_core_bus_device_register(mlxsw_core->bus_info,
-					      mlxsw_core->bus,
-					      mlxsw_core->bus_priv, true,
-					      devlink, extack);
+	err = mlxsw_core_bus_device_register(mlxsw_core->bus_info,
+					     mlxsw_core->bus,
+					     mlxsw_core->bus_priv, true,
+					     devlink, extack);
+	if (err)
+		return err;
+	if (actions_performed)
+		*actions_performed = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT) |
+				     BIT(DEVLINK_RELOAD_ACTION_FW_ACTIVATE);
+
+	return 0;
 }
 
 static int mlxsw_devlink_flash_update(struct devlink *devlink,
@@ -1268,6 +1277,8 @@ 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),
 	.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 32f339fedb21..f0919fa0cd8b 100644
--- a/drivers/net/netdevsim/dev.c
+++ b/drivers/net/netdevsim/dev.c
@@ -697,7 +697,7 @@ 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,
-				struct netlink_ext_ack *extack)
+				enum devlink_reload_action action, struct netlink_ext_ack *extack)
 {
 	struct nsim_dev *nsim_dev = devlink_priv(devlink);
 
@@ -713,10 +713,11 @@ static int nsim_dev_reload_down(struct devlink *devlink, bool netns_change,
 	return 0;
 }
 
-static int nsim_dev_reload_up(struct devlink *devlink,
-			      struct netlink_ext_ack *extack)
+static int nsim_dev_reload_up(struct devlink *devlink, enum devlink_reload_action action,
+			      struct netlink_ext_ack *extack, unsigned long *actions_performed)
 {
 	struct nsim_dev *nsim_dev = devlink_priv(devlink);
+	int err;
 
 	if (nsim_dev->fail_reload) {
 		/* For testing purposes, user set debugfs fail_reload
@@ -726,7 +727,13 @@ static int nsim_dev_reload_up(struct devlink *devlink,
 		return -EINVAL;
 	}
 
-	return nsim_dev_reload_create(nsim_dev, extack);
+	err = nsim_dev_reload_create(nsim_dev, extack);
+	if (err)
+		return err;
+	if (actions_performed)
+		*actions_performed = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT);
+
+	return 0;
 }
 
 static int nsim_dev_info_get(struct devlink *devlink,
@@ -875,6 +882,7 @@ 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),
 	.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 eaec0a8cc5ef..b09db891db04 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -1011,10 +1011,11 @@ enum devlink_trap_group_generic_id {
 	}
 
 struct devlink_ops {
+	unsigned long supported_reload_actions;
 	int (*reload_down)(struct devlink *devlink, bool netns_change,
-			   struct netlink_ext_ack *extack);
-	int (*reload_up)(struct devlink *devlink,
-			 struct netlink_ext_ack *extack);
+			   enum devlink_reload_action action, struct netlink_ext_ack *extack);
+	int (*reload_up)(struct devlink *devlink, enum devlink_reload_action action,
+			 struct netlink_ext_ack *extack, unsigned long *actions_performed);
 	int (*port_type_set)(struct devlink_port *devlink_port,
 			     enum devlink_port_type port_type);
 	int (*port_split)(struct devlink *devlink, unsigned int port_index,
diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index 40d35145c879..a6f64db0bdf3 100644
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -272,6 +272,21 @@ enum {
 	DEVLINK_ATTR_TRAP_METADATA_TYPE_FA_COOKIE,
 };
 
+/**
+ * enum devlink_reload_action - Reload action.
+ * @DEVLINK_RELOAD_ACTION_DRIVER_REINIT: Driver entities re-instantiation.
+ * @DEVLINK_RELOAD_ACTION_FW_ACTIVATE: FW activate.
+ */
+enum devlink_reload_action {
+	DEVLINK_RELOAD_ACTION_UNSPEC,
+	DEVLINK_RELOAD_ACTION_DRIVER_REINIT,
+	DEVLINK_RELOAD_ACTION_FW_ACTIVATE,
+
+	/* Add new reload actions above */
+	__DEVLINK_RELOAD_ACTION_MAX,
+	DEVLINK_RELOAD_ACTION_MAX = __DEVLINK_RELOAD_ACTION_MAX - 1
+};
+
 enum devlink_attr {
 	/* don't change the order or add anything between, this is ABI! */
 	DEVLINK_ATTR_UNSPEC,
@@ -460,6 +475,10 @@ enum devlink_attr {
 
 	DEVLINK_ATTR_PORT_EXTERNAL,		/* u8 */
 	DEVLINK_ATTR_PORT_CONTROLLER_NUMBER,	/* u32 */
+
+	DEVLINK_ATTR_RELOAD_ACTION,		/* u8 */
+	DEVLINK_ATTR_RELOAD_ACTIONS_PERFORMED,	/* nested */
+
 	/* add new attributes above here, update the policy in devlink.c */
 
 	__DEVLINK_ATTR_MAX,
diff --git a/net/core/devlink.c b/net/core/devlink.c
index 19037f114307..f4be1e1bf864 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -462,6 +462,12 @@ static int devlink_nl_put_handle(struct sk_buff *msg, struct devlink *devlink)
 	return 0;
 }
 
+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 int devlink_nl_fill(struct sk_buff *msg, struct devlink *devlink,
 			   enum devlink_command cmd, u32 portid,
 			   u32 seq, int flags)
@@ -2969,29 +2975,72 @@ 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,
-			  struct netlink_ext_ack *extack)
+			  enum devlink_reload_action action, 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, extack);
+	err = devlink->ops->reload_down(devlink, !!dest_net, action, 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, extack);
+	err = devlink->ops->reload_up(devlink, action, extack, actions_performed);
 	devlink_reload_failed_set(devlink, !!err);
 	return err;
 }
 
+static int
+devlink_nl_reload_actions_performed_fill(struct sk_buff *msg,
+					 struct devlink *devlink,
+					 unsigned long actions_performed,
+					 enum devlink_command cmd, u32 portid,
+					 u32 seq, int flags)
+{
+	struct nlattr *actions_performed_attr;
+	void *hdr;
+	int i;
+
+	hdr = genlmsg_put(msg, portid, seq, &devlink_nl_family, flags, cmd);
+	if (!hdr)
+		return -EMSGSIZE;
+
+	if (devlink_nl_put_handle(msg, devlink))
+		goto genlmsg_cancel;
+
+	actions_performed_attr = nla_nest_start(msg, DEVLINK_ATTR_RELOAD_ACTIONS_PERFORMED);
+	if (!actions_performed_attr)
+		goto genlmsg_cancel;
+
+	for (i = 0; i <= DEVLINK_RELOAD_ACTION_MAX; i++) {
+		if (!test_bit(i, &actions_performed))
+			continue;
+		if (nla_put_u8(msg, DEVLINK_ATTR_RELOAD_ACTION, i))
+			goto actions_performed_nest_cancel;
+	}
+	nla_nest_end(msg, actions_performed_attr);
+	genlmsg_end(msg, hdr);
+	return 0;
+
+actions_performed_nest_cancel:
+	nla_nest_cancel(msg, actions_performed_attr);
+genlmsg_cancel:
+	genlmsg_cancel(msg, hdr);
+	return -EMSGSIZE;
+}
+
 static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info)
 {
 	struct devlink *devlink = info->user_ptr[0];
+	enum devlink_reload_action action;
+	unsigned long actions_performed;
 	struct net *dest_net = NULL;
+	struct sk_buff *msg;
 	int err;
 
 	if (!devlink_reload_supported(devlink))
@@ -3011,12 +3060,41 @@ static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info)
 			return PTR_ERR(dest_net);
 	}
 
-	err = devlink_reload(devlink, dest_net, info->extack);
+	if (info->attrs[DEVLINK_ATTR_RELOAD_ACTION])
+		action = nla_get_u8(info->attrs[DEVLINK_ATTR_RELOAD_ACTION]);
+	else
+		action = DEVLINK_RELOAD_ACTION_DRIVER_REINIT;
+
+	if (action == DEVLINK_RELOAD_ACTION_UNSPEC || action > DEVLINK_RELOAD_ACTION_MAX) {
+		NL_SET_ERR_MSG_MOD(info->extack, "Invalid reload action");
+		return -EINVAL;
+	} else if (!devlink_reload_action_is_supported(devlink, action)) {
+		NL_SET_ERR_MSG_MOD(info->extack, "Requested reload action is not supported");
+		return -EOPNOTSUPP;
+	}
+
+	err = devlink_reload(devlink, dest_net, action, info->extack, &actions_performed);
 
 	if (dest_net)
 		put_net(dest_net);
 
-	return err;
+	if (err)
+		return err;
+
+	WARN_ON(!actions_performed);
+	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	err = devlink_nl_reload_actions_performed_fill(msg, devlink, actions_performed,
+						       DEVLINK_CMD_RELOAD, info->snd_portid,
+						       info->snd_seq, 0);
+	if (err) {
+		nlmsg_free(msg);
+		return err;
+	}
+
+	return genlmsg_reply(msg, info);
 }
 
 static int devlink_nl_flash_update_fill(struct sk_buff *msg,
@@ -7047,6 +7125,7 @@ static const struct nla_policy devlink_nl_policy[DEVLINK_ATTR_MAX + 1] = {
 	[DEVLINK_ATTR_TRAP_POLICER_RATE] = { .type = NLA_U64 },
 	[DEVLINK_ATTR_TRAP_POLICER_BURST] = { .type = NLA_U64 },
 	[DEVLINK_ATTR_PORT_FUNCTION] = { .type = NLA_NESTED },
+	[DEVLINK_ATTR_RELOAD_ACTION] = { .type = NLA_U8 },
 };
 
 static const struct genl_ops devlink_nl_ops[] = {
@@ -7372,6 +7451,20 @@ static struct genl_family devlink_nl_family __ro_after_init = {
 	.n_mcgrps	= ARRAY_SIZE(devlink_nl_mcgrps),
 };
 
+static int devlink_reload_actions_verify(struct devlink *devlink)
+{
+	const struct devlink_ops *ops;
+
+	if (!devlink_reload_supported(devlink))
+		return 0;
+
+	ops = devlink->ops;
+	if (WARN_ON(ops->supported_reload_actions >= BIT(__DEVLINK_RELOAD_ACTION_MAX) ||
+		    ops->supported_reload_actions <= BIT(DEVLINK_RELOAD_ACTION_UNSPEC)))
+		return -EINVAL;
+	return 0;
+}
+
 /**
  *	devlink_alloc - Allocate new devlink instance resources
  *
@@ -7392,6 +7485,11 @@ struct devlink *devlink_alloc(const struct devlink_ops *ops, size_t priv_size)
 	if (!devlink)
 		return NULL;
 	devlink->ops = ops;
+	if (devlink_reload_actions_verify(devlink)) {
+		kfree(devlink);
+		return NULL;
+	}
+
 	xa_init_flags(&devlink->snapshot_ids, XA_FLAGS_ALLOC);
 	__devlink_net_set(devlink, &init_net);
 	INIT_LIST_HEAD(&devlink->port_list);
@@ -9657,7 +9755,8 @@ static void __net_exit devlink_pernet_pre_exit(struct net *net)
 		if (net_eq(devlink_net(devlink), net)) {
 			if (WARN_ON(!devlink_reload_supported(devlink)))
 				continue;
-			err = devlink_reload(devlink, &init_net, NULL);
+			err = devlink_reload(devlink, &init_net,
+					     DEVLINK_RELOAD_ACTION_DRIVER_REINIT, NULL, NULL);
 			if (err && err != -EOPNOTSUPP)
 				pr_warn("Failed to reload devlink instance into init_net\n");
 		}
-- 
2.17.1