[PATCH net-next V4 0/6] evlink: Add boot-time eswitch mode defaults

[PATCH net-next V4 0/6] evlink: Add boot-time eswitch mode defaults

[Mark Bloch]

This series adds a devlink_eswitch_mode= kernel command line parameter
for setting a default devlink eswitch mode during boot.

Following the discussion with Jakub[1] and the feedback on the RFC
postings, this version keeps the scope limited to a boot-time devlink
eswitch mode default only.

The option selects either all devlink handles or an explicit
comma-separated handle list:

devlink_eswitch_mode=*=switchdev
devlink_eswitch_mode=pci/0000:08:00.0,pci/0000:09:00.1=switchdev_inactive

The supported modes are legacy, switchdev and switchdev_inactive. The
selected mode is applied through the existing eswitch_mode_set() devlink
operation, the same operation used by the devlink eswitch mode command.

Registration may happen before a driver is ready to change eswitch mode,
so devlink core queues an asynchronous apply request from devl_register().
The worker takes the devlink instance lock before calling into the driver.

After a successful reload that performed DRIVER_REINIT, devlink core
already holds the devlink instance lock and the driver completed
reload_up(), so the default is applied directly from the reload path.

Drivers that know exactly when the device is ready can call
devl_apply_default_esw_mode() directly. mlx5 uses this after initial
probe, when the device is initialized and the devlink lock is already
held.

Patch 1 clears the mlx5 FW reset-in-progress bit before reload.

Patch 2 factors the common eswitch mode set validation into a helper.

Patch 3 adds the devlink_eswitch_mode= parser and documentation.

Patch 4 applies parsed defaults from devlink core.

Patch 5 adds devl_apply_default_esw_mode() for drivers.

Patch 6 wires mlx5 to apply the default after initial probe.

Changelog:

v3 -> v4:

- Rework registration time apply to use per devlink delayed work instead
  of calling eswitch_mode_set() directly from devl_register().

- Apply the default directly after successful DRIVER_REINIT devlink reload,
  where the devlink lock is already held and reload_up() has completed.

- Add devl_apply_default_esw_mode() for drivers that know their exact ready
  point.

- Drop the driver registration-ordering preparation patches that are no
  longer needed with the async registration apply path.

v2 -> v3:

- Change the devlink_eswitch_mode= API syntax to use <selector>=<mode>
  instead of [<selector>]:<mode>, following a comment from Randy Dunlap.

v1 -> v2:

- Move default eswitch mode application into devlink core. The default is
  now applied during devlink registration and after a successful devlink
  reload that performed DRIVER_REINIT.

- Remove the exported devl_apply_default_esw_mode() driver API and the mlx5
  driver-side call to it.

- Skip devlink health recovery notifications while the devlink instance is
  not registered, so drivers can move registration later without early
  health work hitting registration assertions.

- Move mlx5 devlink registration after device initialization, including the
  lightweight init path, so the core can apply the default through the
  normal registration flow.

- Move the matching netdevsim and mlx5 unregister paths before object
  teardown, so unregister notifications come from devl_unregister() and the
  later object teardown paths run while the devlink instance is no longer
  registered.

- Add registration-ordering preparation patches for netdevsim and octeontx2
  AF/PF, so their eswitch state is ready before registration-time defaults
  may call eswitch_mode_set().

[1] lore.kernel.org/r/20260502184153.4fd8d06f@kernel.org/
RFC v1: lore.kernel.org/r/20260506123739.1959770-1-mbloch@nvidia.com/
RFC v2: lore.kernel.org/r/20260510185424.2041415-1-mbloch@nvidia.com/
v1: lore.kernel.org/r/20260521072434.362624-1-tariqt@nvidia.com/
v2: lore.kernel.org/all/20260603193259.3412464-1-mbloch@nvidia.com/
v3: lore.kernel.org/all/20260605181030.3486619-1-mbloch@nvidia.com/

Mark Bloch (6):
  net/mlx5: Clear FW reset-in-progress bit before reload
  devlink: Factor out eswitch mode setting
  devlink: Parse eswitch mode boot defaults
  devlink: Apply eswitch mode boot defaults
  devlink: Add API to apply eswitch mode boot default
  net/mlx5: Apply devlink eswitch mode boot default on probe

 .../admin-guide/kernel-parameters.txt         |  25 ++
 .../networking/devlink/devlink-defaults.rst   |  78 ++++
 Documentation/networking/devlink/index.rst    |   1 +
 .../ethernet/mellanox/mlx5/core/fw_reset.c    |  28 +-
 .../net/ethernet/mellanox/mlx5/core/main.c    |  13 +
 include/net/devlink.h                         |   1 +
 net/devlink/core.c                            | 393 ++++++++++++++++++
 net/devlink/dev.c                             |  33 +-
 net/devlink/devl_internal.h                   |   8 +
 9 files changed, 562 insertions(+), 18 deletions(-)
 create mode 100644 Documentation/networking/devlink/devlink-defaults.rst


base-commit: 805185b7c7a1069e407b6f7b3bc98e44d415f484
-- 
2.43.0

[PATCH net-next V4 1/6] net/mlx5: Clear FW reset-in-progress bit before reload

[Mark Bloch]

mlx5 sets MLX5_FW_RESET_FLAGS_RESET_IN_PROGRESS when acknowledging a sync
reset request. This bit blocks devlink reload and other devlink operations
while the firmware reset is running, but it was kept set until after the
driver reload finished.

Clear the reset-in-progress bit once the reset unload flow is done and PCI
access is back, before reloading the device. For a reset initiated through
devlink, clear it before completing the reload waiter. For a reset reported
through an asynchronous firmware event, keep the unload flow outside
devl_lock, then take devl_lock before clearing the bit and reloading
through the devl-locked load helper.

Reviewed-by: Shay Drori <shayd@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
---
 .../ethernet/mellanox/mlx5/core/fw_reset.c    | 28 +++++++++++--------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c b/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c
index 07440c58713a..7283e5b49eed 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c
@@ -238,24 +238,30 @@ static void mlx5_fw_reset_complete_reload(struct mlx5_core_dev *dev)
 {
 	struct mlx5_fw_reset *fw_reset = dev->priv.fw_reset;
 	struct devlink *devlink = priv_to_devlink(dev);
+	int err;
 
 	/* if this is the driver that initiated the fw reset, devlink completed the reload */
 	if (test_bit(MLX5_FW_RESET_FLAGS_PENDING_COMP, &fw_reset->reset_flags)) {
+		clear_bit(MLX5_FW_RESET_FLAGS_RESET_IN_PROGRESS,
+			  &fw_reset->reset_flags);
 		complete(&fw_reset->done);
-	} else {
-		mlx5_sync_reset_unload_flow(dev, false);
-		if (mlx5_health_wait_pci_up(dev))
-			mlx5_core_err(dev, "reset reload flow aborted, PCI reads still not working\n");
-		else
-			mlx5_load_one(dev, true);
-		devl_lock(devlink);
-		devlink_remote_reload_actions_performed(devlink, 0,
-							BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT) |
-							BIT(DEVLINK_RELOAD_ACTION_FW_ACTIVATE));
-		devl_unlock(devlink);
+		return;
 	}
 
+	mlx5_sync_reset_unload_flow(dev, false);
+	err = mlx5_health_wait_pci_up(dev);
+
+	devl_lock(devlink);
 	clear_bit(MLX5_FW_RESET_FLAGS_RESET_IN_PROGRESS, &fw_reset->reset_flags);
+	if (err)
+		mlx5_core_err(dev, "reset reload flow aborted, PCI reads still not working\n");
+	else
+		mlx5_load_one_devl_locked(dev, true);
+
+	devlink_remote_reload_actions_performed(devlink, 0,
+						BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT) |
+						BIT(DEVLINK_RELOAD_ACTION_FW_ACTIVATE));
+	devl_unlock(devlink);
 }
 
 static void mlx5_stop_sync_reset_poll(struct mlx5_core_dev *dev)
-- 
2.43.0

[PATCH net-next V4 2/6] devlink: Factor out eswitch mode setting

[Mark Bloch]

Move the common eswitch mode set checks into a small helper and use it
from the netlink eswitch set command. Making the same validation
available to the devlink core path that applies eswitch mode defaults.

Signed-off-by: Mark Bloch <mbloch@nvidia.com>
---
 net/devlink/dev.c           | 27 ++++++++++++++++++++-------
 net/devlink/devl_internal.h |  3 +++
 2 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/net/devlink/dev.c b/net/devlink/dev.c
index 57b2b8f03543..4fb02bb993c1 100644
--- a/net/devlink/dev.c
+++ b/net/devlink/dev.c
@@ -702,6 +702,25 @@ int devlink_nl_eswitch_get_doit(struct sk_buff *skb, struct genl_info *info)
 	return genlmsg_reply(msg, info);
 }
 
+int devlink_eswitch_mode_set(struct devlink *devlink,
+			     enum devlink_eswitch_mode mode,
+			     struct netlink_ext_ack *extack)
+{
+	const struct devlink_ops *ops = devlink->ops;
+	int err;
+
+	devl_assert_locked(devlink);
+
+	if (!ops->eswitch_mode_set)
+		return -EOPNOTSUPP;
+
+	err = devlink_rates_check(devlink, devlink_rate_is_node, extack);
+	if (err)
+		return err;
+
+	return ops->eswitch_mode_set(devlink, mode, extack);
+}
+
 int devlink_nl_eswitch_set_doit(struct sk_buff *skb, struct genl_info *info)
 {
 	struct devlink *devlink = info->user_ptr[0];
@@ -712,14 +731,8 @@ int devlink_nl_eswitch_set_doit(struct sk_buff *skb, struct genl_info *info)
 	u16 mode;
 
 	if (info->attrs[DEVLINK_ATTR_ESWITCH_MODE]) {
-		if (!ops->eswitch_mode_set)
-			return -EOPNOTSUPP;
-		err = devlink_rates_check(devlink, devlink_rate_is_node,
-					  info->extack);
-		if (err)
-			return err;
 		mode = nla_get_u16(info->attrs[DEVLINK_ATTR_ESWITCH_MODE]);
-		err = ops->eswitch_mode_set(devlink, mode, info->extack);
+		err = devlink_eswitch_mode_set(devlink, mode, info->extack);
 		if (err)
 			return err;
 	}
diff --git a/net/devlink/devl_internal.h b/net/devlink/devl_internal.h
index e4e48ee2da5a..97be77d3ed42 100644
--- a/net/devlink/devl_internal.h
+++ b/net/devlink/devl_internal.h
@@ -328,6 +328,9 @@ bool devlink_rate_is_node(const struct devlink_rate *devlink_rate);
 int devlink_rates_check(struct devlink *devlink,
 			bool (*rate_filter)(const struct devlink_rate *),
 			struct netlink_ext_ack *extack);
+int devlink_eswitch_mode_set(struct devlink *devlink,
+			     enum devlink_eswitch_mode mode,
+			     struct netlink_ext_ack *extack);
 
 /* Linecards */
 unsigned int devlink_linecard_index(struct devlink_linecard *linecard);
-- 
2.43.0

[PATCH net-next V4 3/6] devlink: Parse eswitch mode boot defaults

[Mark Bloch]

Add devlink_eswitch_mode= kernel command line parsing for a default
eswitch mode.

The supported syntax selects either all devlink handles or one explicit
comma-separated handle list:

  devlink_eswitch_mode=*=<mode>

  devlink_eswitch_mode=<handle>[,<handle>...]=<mode>

where <mode> is one of legacy, switchdev or switchdev_inactive. All
selected handles receive the same mode. Assigning different modes to
different handle lists in the same parameter value is not supported.

Store the parsed selector and mode in devlink core so the default can be
applied by a downstream patch.

Document the devlink_eswitch_mode= syntax and duplicate handle handling.

Signed-off-by: Mark Bloch <mbloch@nvidia.com>
---
 .../admin-guide/kernel-parameters.txt         |  25 ++
 .../networking/devlink/devlink-defaults.rst   |  78 ++++++
 Documentation/networking/devlink/index.rst    |   1 +
 net/devlink/core.c                            | 227 ++++++++++++++++++
 4 files changed, 331 insertions(+)
 create mode 100644 Documentation/networking/devlink/devlink-defaults.rst

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index b5493a7f8f22..117300dd589c 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1249,6 +1249,31 @@ Kernel parameters
 	dell_smm_hwmon.fan_max=
 			[HW] Maximum configurable fan speed.
 
+	devlink_eswitch_mode=
+			[NET]
+			Format:
+			<selector>=<mode>
+
+			<selector>:
+			* | <handle>[,<handle>...]
+
+			<handle>:
+			<bus-name>/<dev-name>
+
+			Configure default devlink eswitch mode for matching
+			devlink instances during device initialization.
+
+			<mode>:
+			legacy | switchdev | switchdev_inactive
+
+			Examples:
+			devlink_eswitch_mode=*=switchdev
+			devlink_eswitch_mode=pci/0000:08:00.0=switchdev
+			devlink_eswitch_mode=pci/0000:08:00.0,pci/0000:09:00.1=switchdev_inactive
+
+			See Documentation/networking/devlink/devlink-defaults.rst
+			for the full syntax.
+
 	dfltcc=		[HW,S390]
 			Format: { on | off | def_only | inf_only | always }
 			on:       s390 zlib hardware support for compression on
diff --git a/Documentation/networking/devlink/devlink-defaults.rst b/Documentation/networking/devlink/devlink-defaults.rst
new file mode 100644
index 000000000000..380c9e99210e
--- /dev/null
+++ b/Documentation/networking/devlink/devlink-defaults.rst
@@ -0,0 +1,78 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==============================
+Devlink Eswitch Mode Defaults
+==============================
+
+Devlink eswitch mode defaults allow the eswitch mode to be provided on the
+kernel command line and applied to matching devlink instances during device
+initialization.
+
+The devlink device is selected by its devlink handle. For PCI devices this is
+the same handle shown by ``devlink dev show``, for example
+``pci/0000:08:00.0``.
+
+Kernel command line syntax
+==========================
+
+Defaults are specified with the ``devlink_eswitch_mode=`` kernel command line
+parameter.
+
+The general syntax is::
+
+  devlink_eswitch_mode=<selector>=<mode>
+
+``<selector>`` is either ``*`` or one or more devlink handles::
+
+  * | <bus-name>/<dev-name>[,<bus-name>/<dev-name>...]
+
+``*`` applies the mode to every devlink instance. All handles in the same
+selector receive the same eswitch mode.
+
+``<mode>`` is one of ``legacy``, ``switchdev`` or ``switchdev_inactive``.
+
+Syntax rules
+------------
+
+The following syntax rules apply:
+
+* Specify the default in one ``devlink_eswitch_mode=`` parameter. Repeated
+  ``devlink_eswitch_mode=`` parameters are not accumulated.
+* The ``devlink_eswitch_mode=`` value is limited by the kernel command line
+  size.
+* Whitespace is not allowed within the parameter value.
+* ``<selector>`` must be either ``*`` or a handle list. ``*`` cannot be
+  combined with explicit handles.
+* ``<bus-name>`` and ``<dev-name>`` must not be empty.
+* ``<dev-name>`` may contain ``:``. This allows PCI names such as
+  ``0000:08:00.0``.
+* Handles must not contain whitespace, ``*``, ``=`` or more than one ``/``.
+* A comma separates handles.
+* Comma-separated default assignments are not supported.
+* Duplicate handles are rejected and the devlink eswitch mode default is
+  ignored.
+
+The eswitch mode default corresponds to the userspace command::
+
+  devlink dev eswitch set <handle> mode <value>
+
+
+Examples
+========
+
+Set all devlink instances to switchdev mode::
+
+  devlink_eswitch_mode=*=switchdev
+
+Set one PCI devlink instance to switchdev mode::
+
+  devlink_eswitch_mode=pci/0000:08:00.0=switchdev
+
+Set two PCI devlink instances to switchdev inactive mode::
+
+  devlink_eswitch_mode=pci/0000:08:00.0,pci/0000:09:00.1=switchdev_inactive
+
+The following is invalid because comma-separated default assignments are not
+supported::
+
+  devlink_eswitch_mode=pci/0000:08:00.0=switchdev,pci/0000:09:00.0=switchdev_inactive
diff --git a/Documentation/networking/devlink/index.rst b/Documentation/networking/devlink/index.rst
index 32f70879ddd0..93f09cb18c44 100644
--- a/Documentation/networking/devlink/index.rst
+++ b/Documentation/networking/devlink/index.rst
@@ -56,6 +56,7 @@ general.
    :maxdepth: 1
 
    devlink-dpipe
+   devlink-defaults
    devlink-eswitch-attr
    devlink-flash
    devlink-health
diff --git a/net/devlink/core.c b/net/devlink/core.c
index fe9f6a0a67d5..5126509a9c4e 100644
--- a/net/devlink/core.c
+++ b/net/devlink/core.c
@@ -4,6 +4,10 @@
  * Copyright (c) 2016 Jiri Pirko <jiri@mellanox.com>
  */
 
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/string.h>
 #include <net/genetlink.h>
 #define CREATE_TRACE_POINTS
 #include <trace/events/devlink.h>
@@ -16,6 +20,193 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(devlink_trap_report);
 
 DEFINE_XARRAY_FLAGS(devlinks, XA_FLAGS_ALLOC);
 
+static char *devlink_default_esw_mode_param;
+static bool devlink_default_esw_mode_match_all;
+static enum devlink_eswitch_mode devlink_default_esw_mode;
+static LIST_HEAD(devlink_default_esw_mode_nodes);
+
+struct devlink_default_esw_mode_node {
+	struct list_head list;
+	char *bus_name;
+	char *dev_name;
+};
+
+static int __init
+devlink_default_esw_mode_to_value(const char *str,
+				  enum devlink_eswitch_mode *mode)
+{
+	if (!strcmp(str, "legacy")) {
+		*mode = DEVLINK_ESWITCH_MODE_LEGACY;
+		return 0;
+	}
+	if (!strcmp(str, "switchdev")) {
+		*mode = DEVLINK_ESWITCH_MODE_SWITCHDEV;
+		return 0;
+	}
+	if (!strcmp(str, "switchdev_inactive")) {
+		*mode = DEVLINK_ESWITCH_MODE_SWITCHDEV_INACTIVE;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static int __init
+devlink_default_esw_mode_handle_parse(char *handle, char **bus_name,
+				      char **dev_name)
+{
+	char *slash;
+	char *p;
+
+	if (!*handle)
+		return -EINVAL;
+
+	for (p = handle; *p; p++) {
+		if (*p == '*' || *p == '=')
+			return -EINVAL;
+	}
+
+	slash = strchr(handle, '/');
+	if (!slash || slash == handle || !slash[1])
+		return -EINVAL;
+	if (strchr(slash + 1, '/'))
+		return -EINVAL;
+
+	*slash = '\0';
+
+	*bus_name = handle;
+	*dev_name = slash + 1;
+	return 0;
+}
+
+static struct devlink_default_esw_mode_node *
+devlink_default_esw_mode_node_find(const char *bus_name, const char *dev_name)
+{
+	struct devlink_default_esw_mode_node *node;
+
+	list_for_each_entry(node, &devlink_default_esw_mode_nodes, list) {
+		if (!strcmp(node->bus_name, bus_name) &&
+		    !strcmp(node->dev_name, dev_name))
+			return node;
+	}
+
+	return NULL;
+}
+
+static int __init
+devlink_default_esw_mode_node_add(const char *bus_name, const char *dev_name)
+{
+	struct devlink_default_esw_mode_node *node;
+
+	if (devlink_default_esw_mode_node_find(bus_name, dev_name))
+		return -EEXIST;
+
+	node = kzalloc_obj(*node);
+	if (!node)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&node->list);
+	node->bus_name = kstrdup(bus_name, GFP_KERNEL);
+	node->dev_name = kstrdup(dev_name, GFP_KERNEL);
+	if (!node->bus_name || !node->dev_name) {
+		kfree(node->bus_name);
+		kfree(node->dev_name);
+		kfree(node);
+		return -ENOMEM;
+	}
+
+	list_add_tail(&node->list, &devlink_default_esw_mode_nodes);
+	return 0;
+}
+
+static int __init devlink_default_esw_mode_handles_parse(char *handles)
+{
+	char *handle;
+	int err;
+
+	if (!strcmp(handles, "*")) {
+		devlink_default_esw_mode_match_all = true;
+		return 0;
+	}
+
+	while ((handle = strsep(&handles, ",")) != NULL) {
+		char *bus_name;
+		char *dev_name;
+
+		err = devlink_default_esw_mode_handle_parse(handle, &bus_name,
+							    &dev_name);
+		if (err)
+			return err;
+
+		err = devlink_default_esw_mode_node_add(bus_name, dev_name);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+static void __init
+devlink_default_esw_mode_node_free(struct devlink_default_esw_mode_node *node)
+{
+	kfree(node->bus_name);
+	kfree(node->dev_name);
+	kfree(node);
+}
+
+static void __init devlink_default_esw_mode_nodes_clear(void)
+{
+	struct devlink_default_esw_mode_node *node;
+	struct devlink_default_esw_mode_node *node_tmp;
+
+	list_for_each_entry_safe(node, node_tmp,
+				 &devlink_default_esw_mode_nodes, list) {
+		list_del(&node->list);
+		devlink_default_esw_mode_node_free(node);
+	}
+
+	devlink_default_esw_mode_match_all = false;
+}
+
+static int __init devlink_default_esw_mode_parse(char *str)
+{
+	char *handles;
+	char *separator;
+	char *mode;
+	enum devlink_eswitch_mode esw_mode;
+	int err;
+
+	if (!*str)
+		return -EINVAL;
+
+	separator = strrchr(str, '=');
+	if (!separator || separator == str || !separator[1])
+		return -EINVAL;
+
+	*separator = '\0';
+	handles = str;
+	mode = separator + 1;
+
+	err = devlink_default_esw_mode_to_value(mode, &esw_mode);
+	if (err)
+		return err;
+
+	err = devlink_default_esw_mode_handles_parse(handles);
+	if (err)
+		devlink_default_esw_mode_nodes_clear();
+	else
+		devlink_default_esw_mode = esw_mode;
+
+	return err;
+}
+
+static int __init devlink_default_esw_mode_setup(char *str)
+{
+	devlink_default_esw_mode_param = str;
+	return 1;
+}
+__setup("devlink_eswitch_mode=", devlink_default_esw_mode_setup);
+
 static struct devlink *devlinks_xa_get(unsigned long index)
 {
 	struct devlink *devlink;
@@ -382,6 +573,14 @@ struct devlink *devlinks_xa_lookup_get(struct net *net, unsigned long index)
 /**
  * devl_register - Register devlink instance
  * @devlink: devlink
+ *
+ * Make @devlink visible to userspace. Drivers must call this only after the
+ * instance is fully initialized and its devlink operations can be called.
+ *
+ * Context: Caller must hold the devlink instance lock. Use devlink_register()
+ * when the lock is not already held.
+ *
+ * Return: 0 on success.
  */
 int devl_register(struct devlink *devlink)
 {
@@ -580,6 +779,31 @@ static int __init devlink_init(void)
 {
 	int err;
 
+	if (devlink_default_esw_mode_param) {
+		char *def;
+
+		def = kstrdup(devlink_default_esw_mode_param, GFP_KERNEL);
+		if (!def) {
+			devlink_default_esw_mode_param = NULL;
+			pr_warn("devlink: devlink_eswitch_mode parameter ignored, failed to allocate memory\n");
+		} else {
+			err = devlink_default_esw_mode_parse(def);
+			kfree(def);
+			if (err == -EEXIST) {
+				devlink_default_esw_mode_param = NULL;
+				pr_warn("devlink: duplicate eswitch mode handles ignored\n");
+			} else if (err == -EINVAL) {
+				devlink_default_esw_mode_param = NULL;
+				pr_warn("devlink: invalid devlink_eswitch_mode parameter ignored\n");
+			} else if (err == -ENOMEM) {
+				devlink_default_esw_mode_param = NULL;
+				pr_warn("devlink: devlink_eswitch_mode parameter ignored, failed to allocate memory\n");
+			} else if (err) {
+				goto out;
+			}
+		}
+	}
+
 	err = register_pernet_subsys(&devlink_pernet_ops);
 	if (err)
 		goto out;
@@ -595,7 +819,10 @@ static int __init devlink_init(void)
 out_unreg_pernet_subsys:
 	unregister_pernet_subsys(&devlink_pernet_ops);
 out:
+	if (err)
+		devlink_default_esw_mode_nodes_clear();
 	WARN_ON(err);
+
 	return err;
 }
 
-- 
2.43.0

[PATCH net-next V4 4/6] devlink: Apply eswitch mode boot defaults

[Mark Bloch]

Apply parsed devlink_eswitch_mode= defaults after devlink registration
and after successful reload.

devl_register() may still be called before the device is ready for an
eswitch mode change, so keep a per-devlink delayed work item and pending
flag for the registration path. Registration queues the work, and the
worker tries to take the devlink instance lock.

If the lock is busy, the worker requeues itself with a delay.

For successful reloads that performed DRIVER_REINIT, devlink_reload()
already holds the devlink instance lock and the driver has completed
reload_up(). Clear pending work and apply the default directly from the
reload path instead of queueing work.

If a user sets eswitch mode through netlink before the pending
registration work runs, clear the pending flag so the queued default does
not override that user request. Cancel pending default apply work when
freeing the devlink instance.

Signed-off-by: Mark Bloch <mbloch@nvidia.com>
---
 net/devlink/core.c          | 198 +++++++++++++++++++++++++++++++-----
 net/devlink/dev.c           |   6 ++
 net/devlink/devl_internal.h |   5 +
 3 files changed, 182 insertions(+), 27 deletions(-)

diff --git a/net/devlink/core.c b/net/devlink/core.c
index 5126509a9c4e..998e4ffd5dce 100644
--- a/net/devlink/core.c
+++ b/net/devlink/core.c
@@ -5,6 +5,7 @@
  */
 
 #include <linux/init.h>
+#include <linux/jiffies.h>
 #include <linux/list.h>
 #include <linux/slab.h>
 #include <linux/string.h>
@@ -22,8 +23,12 @@ DEFINE_XARRAY_FLAGS(devlinks, XA_FLAGS_ALLOC);
 
 static char *devlink_default_esw_mode_param;
 static bool devlink_default_esw_mode_match_all;
+static bool devlink_default_esw_mode_enabled;
 static enum devlink_eswitch_mode devlink_default_esw_mode;
 static LIST_HEAD(devlink_default_esw_mode_nodes);
+static struct workqueue_struct *devlink_default_esw_mode_wq;
+
+#define DEVLINK_DEFAULT_ESW_MODE_APPLY_DELAY msecs_to_jiffies(100)
 
 struct devlink_default_esw_mode_node {
 	struct list_head list;
@@ -166,6 +171,7 @@ static void __init devlink_default_esw_mode_nodes_clear(void)
 	}
 
 	devlink_default_esw_mode_match_all = false;
+	devlink_default_esw_mode_enabled = false;
 }
 
 static int __init devlink_default_esw_mode_parse(char *str)
@@ -192,14 +198,113 @@ static int __init devlink_default_esw_mode_parse(char *str)
 		return err;
 
 	err = devlink_default_esw_mode_handles_parse(handles);
-	if (err)
+	if (err) {
 		devlink_default_esw_mode_nodes_clear();
-	else
+	} else {
 		devlink_default_esw_mode = esw_mode;
+		devlink_default_esw_mode_enabled = true;
+	}
 
 	return err;
 }
 
+static bool devlink_default_esw_mode_match(struct devlink *devlink)
+{
+	const char *bus_name = devlink_bus_name(devlink);
+	const char *dev_name = devlink_dev_name(devlink);
+	struct devlink_default_esw_mode_node *node;
+
+	if (devlink_default_esw_mode_match_all)
+		return true;
+
+	node = devlink_default_esw_mode_node_find(bus_name, dev_name);
+	return !!node;
+}
+
+void devlink_default_esw_mode_apply(struct devlink *devlink)
+{
+	const struct devlink_ops *ops = devlink->ops;
+	int err;
+
+	devl_assert_locked(devlink);
+
+	if (!devlink_default_esw_mode_match(devlink))
+		return;
+
+	if (!ops->eswitch_mode_set) {
+		if (!devlink_default_esw_mode_match_all)
+			devl_warn(devlink,
+				  "devlink_eswitch_mode= selected this device but eswitch mode setting is not supported\n");
+		return;
+	}
+
+	err = devlink_eswitch_mode_set(devlink, devlink_default_esw_mode, NULL);
+	if (err)
+		devl_warn(devlink,
+			  "Couldn't apply default eswitch mode, err %d\n",
+			  err);
+}
+
+static void
+devlink_default_esw_mode_apply_queue(struct devlink *devlink,
+				     unsigned long delay)
+{
+	if (!devlink_default_esw_mode_enabled || !devlink_default_esw_mode_wq)
+		return;
+	if (!devlink_try_get(devlink))
+		return;
+	if (!queue_delayed_work(devlink_default_esw_mode_wq,
+				&devlink->default_esw_mode_apply_dw,
+				delay))
+		devlink_put(devlink);
+}
+
+static void devlink_default_esw_mode_apply_work(struct work_struct *work)
+{
+	unsigned long delay = DEVLINK_DEFAULT_ESW_MODE_APPLY_DELAY;
+	struct delayed_work *dwork = to_delayed_work(work);
+	struct devlink *devlink;
+
+	devlink = container_of(dwork, struct devlink,
+			       default_esw_mode_apply_dw);
+	if (!devl_trylock(devlink)) {
+		if (__devl_is_registered(devlink))
+			devlink_default_esw_mode_apply_queue(devlink, delay);
+		devlink_put(devlink);
+		return;
+	}
+
+	if (devl_is_registered(devlink) &&
+	    devlink->default_esw_mode_apply_pending) {
+		devlink_default_esw_mode_apply(devlink);
+		devlink->default_esw_mode_apply_pending = false;
+	}
+
+	devl_unlock(devlink);
+	devlink_put(devlink);
+}
+
+void devlink_default_esw_mode_apply_schedule(struct devlink *devlink)
+{
+	devl_assert_locked(devlink);
+
+	devlink->default_esw_mode_apply_pending = true;
+	devlink_default_esw_mode_apply_queue(devlink, 0);
+}
+
+void devlink_default_esw_mode_apply_disable(struct devlink *devlink)
+{
+	devl_assert_locked(devlink);
+
+	devlink->default_esw_mode_apply_pending = false;
+}
+
+static void devlink_default_esw_mode_apply_cancel(struct devlink *devlink)
+{
+	if (cancel_delayed_work_sync(&devlink->default_esw_mode_apply_dw))
+		devlink_put(devlink);
+}
+
 static int __init devlink_default_esw_mode_setup(char *str)
 {
 	devlink_default_esw_mode_param = str;
@@ -577,6 +682,12 @@ struct devlink *devlinks_xa_lookup_get(struct net *net, unsigned long index)
  * Make @devlink visible to userspace. Drivers must call this only after the
  * instance is fully initialized and its devlink operations can be called.
  *
+ * If a matching devlink_eswitch_mode= default was provided on the kernel
+ * command line, devlink core schedules async work to apply it after
+ * registration. Drivers implementing eswitch_mode_set() must therefore be
+ * ready to perform the same work as a userspace eswitch mode set request from
+ * this point, including creation of representors and other eswitch state.
+ *
  * Context: Caller must hold the devlink instance lock. Use devlink_register()
  * when the lock is not already held.
  *
@@ -590,6 +701,7 @@ int devl_register(struct devlink *devlink)
 	xa_set_mark(&devlinks, devlink->index, DEVLINK_REGISTERED);
 	devlink_notify_register(devlink);
 	devlink_rel_nested_in_notify(devlink);
+	devlink_default_esw_mode_apply_schedule(devlink);
 
 	return 0;
 }
@@ -612,6 +724,7 @@ void devl_unregister(struct devlink *devlink)
 	ASSERT_DEVLINK_REGISTERED(devlink);
 	devl_assert_locked(devlink);
 
+	devlink_default_esw_mode_apply_disable(devlink);
 	devlink_notify_unregister(devlink);
 	xa_clear_mark(&devlinks, devlink->index, DEVLINK_REGISTERED);
 	devlink_rel_put(devlink);
@@ -673,6 +786,9 @@ struct devlink *__devlink_alloc(const struct devlink_ops *ops, size_t priv_size,
 	INIT_LIST_HEAD(&devlink->trap_group_list);
 	INIT_LIST_HEAD(&devlink->trap_policer_list);
 	INIT_RCU_WORK(&devlink->rwork, devlink_release);
+	INIT_DELAYED_WORK(&devlink->default_esw_mode_apply_dw,
+			  devlink_default_esw_mode_apply_work);
+	devlink->default_esw_mode_apply_pending = true;
 	lockdep_register_key(&devlink->lock_key);
 	mutex_init(&devlink->lock);
 	lockdep_set_class(&devlink->lock, &devlink->lock_key);
@@ -716,6 +832,7 @@ EXPORT_SYMBOL_GPL(devlink_alloc_ns);
 void devlink_free(struct devlink *devlink)
 {
 	ASSERT_DEVLINK_NOT_REGISTERED(devlink);
+	devlink_default_esw_mode_apply_cancel(devlink);
 
 	devlink_rel_put(devlink);
 
@@ -775,35 +892,59 @@ static struct notifier_block devlink_port_netdevice_nb = {
 	.notifier_call = devlink_port_netdevice_event,
 };
 
-static int __init devlink_init(void)
+static int __init devlink_default_esw_mode_init(void)
 {
+	char *def;
 	int err;
 
-	if (devlink_default_esw_mode_param) {
-		char *def;
-
-		def = kstrdup(devlink_default_esw_mode_param, GFP_KERNEL);
-		if (!def) {
-			devlink_default_esw_mode_param = NULL;
-			pr_warn("devlink: devlink_eswitch_mode parameter ignored, failed to allocate memory\n");
-		} else {
-			err = devlink_default_esw_mode_parse(def);
-			kfree(def);
-			if (err == -EEXIST) {
-				devlink_default_esw_mode_param = NULL;
-				pr_warn("devlink: duplicate eswitch mode handles ignored\n");
-			} else if (err == -EINVAL) {
-				devlink_default_esw_mode_param = NULL;
-				pr_warn("devlink: invalid devlink_eswitch_mode parameter ignored\n");
-			} else if (err == -ENOMEM) {
-				devlink_default_esw_mode_param = NULL;
-				pr_warn("devlink: devlink_eswitch_mode parameter ignored, failed to allocate memory\n");
-			} else if (err) {
-				goto out;
-			}
-		}
+	if (!devlink_default_esw_mode_param)
+		return 0;
+
+	def = kstrdup(devlink_default_esw_mode_param, GFP_KERNEL);
+	if (!def) {
+		devlink_default_esw_mode_param = NULL;
+		pr_warn("devlink: devlink_eswitch_mode parameter ignored, failed to allocate memory\n");
+		return 0;
+	}
+
+	err = devlink_default_esw_mode_parse(def);
+	kfree(def);
+	if (err == -EEXIST) {
+		devlink_default_esw_mode_param = NULL;
+		pr_warn("devlink: duplicate eswitch mode handles ignored\n");
+		return 0;
+	} else if (err == -EINVAL) {
+		devlink_default_esw_mode_param = NULL;
+		pr_warn("devlink: invalid devlink_eswitch_mode parameter ignored\n");
+		return 0;
+	} else if (err == -ENOMEM) {
+		devlink_default_esw_mode_param = NULL;
+		pr_warn("devlink: devlink_eswitch_mode parameter ignored, failed to allocate memory\n");
+		return 0;
+	} else if (err) {
+		return err;
 	}
 
+	devlink_default_esw_mode_wq = alloc_workqueue("devlink_default_esw_mode",
+						      WQ_UNBOUND | WQ_MEM_RECLAIM,
+						      0);
+	if (!devlink_default_esw_mode_wq) {
+		devlink_default_esw_mode_param = NULL;
+		devlink_default_esw_mode_nodes_clear();
+		pr_warn("devlink: devlink_eswitch_mode parameter ignored, failed to allocate workqueue\n");
+	}
+
+	return 0;
+}
+
+static int __init devlink_init(void)
+{
+	int err;
+
+	err = devlink_default_esw_mode_init();
+	if (err)
+		goto out;
+
 	err = register_pernet_subsys(&devlink_pernet_ops);
 	if (err)
 		goto out;
@@ -819,8 +960,11 @@ static int __init devlink_init(void)
 out_unreg_pernet_subsys:
 	unregister_pernet_subsys(&devlink_pernet_ops);
 out:
-	if (err)
+	if (err) {
+		if (devlink_default_esw_mode_wq)
+			destroy_workqueue(devlink_default_esw_mode_wq);
 		devlink_default_esw_mode_nodes_clear();
+	}
 	WARN_ON(err);
 
 	return err;
diff --git a/net/devlink/dev.c b/net/devlink/dev.c
index 4fb02bb993c1..7f6ed52a5f73 100644
--- a/net/devlink/dev.c
+++ b/net/devlink/dev.c
@@ -478,6 +478,11 @@ int devlink_reload(struct devlink *devlink, struct net *dest_net,
 		return err;
 
 	WARN_ON(!(*actions_performed & BIT(action)));
+	if (*actions_performed & BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT)) {
+		devlink_default_esw_mode_apply_disable(devlink);
+		devlink_default_esw_mode_apply(devlink);
+	}
+
 	/* Catch driver on updating the remote action within devlink reload */
 	WARN_ON(memcmp(remote_reload_stats, devlink->stats.remote_reload_stats,
 		       sizeof(remote_reload_stats)));
@@ -731,6 +736,7 @@ int devlink_nl_eswitch_set_doit(struct sk_buff *skb, struct genl_info *info)
 	u16 mode;
 
 	if (info->attrs[DEVLINK_ATTR_ESWITCH_MODE]) {
+		devlink_default_esw_mode_apply_disable(devlink);
 		mode = nla_get_u16(info->attrs[DEVLINK_ATTR_ESWITCH_MODE]);
 		err = devlink_eswitch_mode_set(devlink, mode, info->extack);
 		if (err)
diff --git a/net/devlink/devl_internal.h b/net/devlink/devl_internal.h
index 97be77d3ed42..d6ff233da974 100644
--- a/net/devlink/devl_internal.h
+++ b/net/devlink/devl_internal.h
@@ -58,8 +58,10 @@ struct devlink {
 	struct mutex lock;
 	struct lock_class_key lock_key;
 	u8 reload_failed:1;
+	u8 default_esw_mode_apply_pending:1;
 	refcount_t refcount;
 	struct rcu_work rwork;
+	struct delayed_work default_esw_mode_apply_dw;
 	struct devlink_rel *rel;
 	struct xarray nested_rels;
 	char priv[] __aligned(NETDEV_ALIGN);
@@ -71,6 +73,9 @@ extern struct genl_family devlink_nl_family;
 struct devlink *__devlink_alloc(const struct devlink_ops *ops, size_t priv_size,
 				struct net *net, struct device *dev,
 				const struct device_driver *dev_driver);
+void devlink_default_esw_mode_apply(struct devlink *devlink);
+void devlink_default_esw_mode_apply_schedule(struct devlink *devlink);
+void devlink_default_esw_mode_apply_disable(struct devlink *devlink);
 
 #define devl_warn(devlink, format, args...)				\
 	do {								\
-- 
2.43.0

[PATCH net-next V4 5/6] devlink: Add API to apply eswitch mode boot default

[Mark Bloch]

Add devl_apply_default_esw_mode() for drivers that can apply the
devlink_eswitch_mode= boot default once their device is ready instead of
waiting for the asynchronous registration work.

Signed-off-by: Mark Bloch <mbloch@nvidia.com>
---
 include/net/devlink.h |  1 +
 net/devlink/core.c    | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/include/net/devlink.h b/include/net/devlink.h
index dd546dbd57cf..b71d282c6d52 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -1652,6 +1652,7 @@ static inline struct devlink *devlink_alloc(const struct devlink_ops *ops,
 
 int devl_register(struct devlink *devlink);
 void devl_unregister(struct devlink *devlink);
+void devl_apply_default_esw_mode(struct devlink *devlink);
 void devlink_register(struct devlink *devlink);
 void devlink_unregister(struct devlink *devlink);
 void devlink_free(struct devlink *devlink);
diff --git a/net/devlink/core.c b/net/devlink/core.c
index 998e4ffd5dce..d8f273e1732c 100644
--- a/net/devlink/core.c
+++ b/net/devlink/core.c
@@ -299,6 +299,28 @@ void devlink_default_esw_mode_apply_disable(struct devlink *devlink)
 	devlink->default_esw_mode_apply_pending = false;
 }
 
+/**
+ * devl_apply_default_esw_mode - Apply devlink eswitch mode boot default
+ * @devlink: devlink
+ *
+ * Apply a matching devlink_eswitch_mode= boot default immediately. Drivers may
+ * use this helper when the device is ready for an eswitch mode change and the
+ * caller already holds the devlink instance lock.
+ *
+ * Any pending asynchronous default apply is cleared before applying the
+ * default, so work queued by devl_register() will not apply it again.
+ *
+ * Context: Caller must hold the devlink instance lock.
+ */
+void devl_apply_default_esw_mode(struct devlink *devlink)
+{
+	devl_assert_locked(devlink);
+
+	devlink->default_esw_mode_apply_pending = false;
+	devlink_default_esw_mode_apply(devlink);
+}
+EXPORT_SYMBOL_GPL(devl_apply_default_esw_mode);
+
 static void devlink_default_esw_mode_apply_cancel(struct devlink *devlink)
 {
 	if (cancel_delayed_work_sync(&devlink->default_esw_mode_apply_dw))
-- 
2.43.0

[PATCH net-next V4 6/6] net/mlx5: Apply devlink eswitch mode boot default on probe

[Mark Bloch]

Apply devlink_eswitch_mode= boot defaults for mlx5 after the initial
probe finishes device initialization while holding the devlink instance
lock.

At this point the devlink instance is registered and mlx5 can perform an
eswitch mode change. Calling devl_apply_default_esw_mode() also clears
any pending default apply work queued by devl_register(), so the queued
work will not apply the same default again.

Keep this call in mlx5_init_one() rather than the lower-level
devl-locked init helper. That helper is also used by devlink reload, and
devlink core already applies the boot default after a successful
DRIVER_REINIT reload.

Signed-off-by: Mark Bloch <mbloch@nvidia.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/main.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/main.c b/drivers/net/ethernet/mellanox/mlx5/core/main.c
index 643b4aac2033..0712efea74cc 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/main.c
@@ -1392,6 +1392,17 @@ static void mlx5_unload(struct mlx5_core_dev *dev)
 	mlx5_free_bfreg(dev, &dev->priv.bfreg);
 }
 
+static void mlx5_devl_apply_default_esw_mode(struct mlx5_core_dev *dev)
+{
+	struct devlink *devlink = priv_to_devlink(dev);
+
+	if (!MLX5_ESWITCH_MANAGER(dev))
+		return;
+
+	devl_assert_locked(devlink);
+	devl_apply_default_esw_mode(devlink);
+}
+
 int mlx5_init_one_devl_locked(struct mlx5_core_dev *dev)
 {
 	bool light_probe = mlx5_dev_is_lightweight(dev);
@@ -1471,6 +1482,8 @@ int mlx5_init_one(struct mlx5_core_dev *dev)
 	err = mlx5_init_one_devl_locked(dev);
 	if (err)
 		devl_unregister(devlink);
+	else
+		mlx5_devl_apply_default_esw_mode(dev);
 unlock:
 	devl_unlock(devlink);
 	return err;
-- 
2.43.0