Commit 4ab45e97 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'autoload-dsa-tagging-driver-when-dynamically-changing-protocol' 

Vladimir Oltean says:

====================
Autoload DSA tagging driver when dynamically changing protocol

This patch set solves the issue reported by Michael and Heiko here:
https://lore.kernel.org/lkml/20221027113248.420216-1-michael@walle.cc/
making full use of Michael's suggestion of having two modaliases: one
gets used for loading the tagging protocol when it's the default one
reported by the switch driver, the other gets loaded at user's request,
by name.

  # modinfo tag_ocelot
  filename:       /lib/modules/6.1.0-rc4+/kernel/net/dsa/tag_ocelot.ko
  license:        GPL v2
  alias:          dsa_tag:seville
  alias:          dsa_tag:id-21
  alias:          dsa_tag:ocelot
  alias:          dsa_tag:id-15
  depends:        dsa_core
  intree:         Y
  name:           tag_ocelot
  vermagic:       6.1.0-rc4+ SMP preempt mod_unload modversions aarch64

Tested on NXP LS1028A-RDB with the following device tree addition:

&mscc_felix_port4 {
	dsa-tag-protocol = "ocelot-8021q";
};

&mscc_felix_port5 {
	dsa-tag-protocol = "ocelot-8021q";
};

CONFIG_NET_DSA and everything that depends on it is built as module.
Everything auto-loads, and "cat /sys/class/net/eno2/dsa/tagging" shows
"ocelot-8021q". Traffic works as well. Furthermore, "echo ocelot-8021q"
into the aforementioned sysfs file now auto-loads the driver for it.
====================

Link: https://lore.kernel.org/r/20221115011847.2843127-1-vladimir.oltean@nxp.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 4a8c1438 0184c07a

include/net/dsa.h

+0 −70
Original line number Diff line number Diff line
@@ -118,10 +118,6 @@ struct dsa_netdevice_ops { 
			     int cmd);

};



#define DSA_TAG_DRIVER_ALIAS "dsa_tag-"

#define MODULE_ALIAS_DSA_TAG_DRIVER(__proto)				\

	MODULE_ALIAS(DSA_TAG_DRIVER_ALIAS __stringify(__proto##_VALUE))



struct dsa_lag {

	struct net_device *dev;

	unsigned int id;
@@ -1400,70 +1396,4 @@ static inline bool dsa_slave_dev_check(const struct net_device *dev) 
netdev_tx_t dsa_enqueue_skb(struct sk_buff *skb, struct net_device *dev);

void dsa_port_phylink_mac_change(struct dsa_switch *ds, int port, bool up);



struct dsa_tag_driver {

	const struct dsa_device_ops *ops;

	struct list_head list;

	struct module *owner;

};



void dsa_tag_drivers_register(struct dsa_tag_driver *dsa_tag_driver_array[],

			      unsigned int count,

			      struct module *owner);

void dsa_tag_drivers_unregister(struct dsa_tag_driver *dsa_tag_driver_array[],

				unsigned int count);



#define dsa_tag_driver_module_drivers(__dsa_tag_drivers_array, __count)	\

static int __init dsa_tag_driver_module_init(void)			\

{									\

	dsa_tag_drivers_register(__dsa_tag_drivers_array, __count,	\

				 THIS_MODULE);				\

	return 0;							\

}									\

module_init(dsa_tag_driver_module_init);				\

									\

static void __exit dsa_tag_driver_module_exit(void)			\

{									\

	dsa_tag_drivers_unregister(__dsa_tag_drivers_array, __count);	\

}									\

module_exit(dsa_tag_driver_module_exit)



/**

 * module_dsa_tag_drivers() - Helper macro for registering DSA tag

 * drivers

 * @__ops_array: Array of tag driver structures

 *

 * Helper macro for DSA tag drivers which do not do anything special

 * in module init/exit. Each module may only use this macro once, and

 * calling it replaces module_init() and module_exit().

 */

#define module_dsa_tag_drivers(__ops_array)				\

dsa_tag_driver_module_drivers(__ops_array, ARRAY_SIZE(__ops_array))



#define DSA_TAG_DRIVER_NAME(__ops) dsa_tag_driver ## _ ## __ops



/* Create a static structure we can build a linked list of dsa_tag

 * drivers

 */

#define DSA_TAG_DRIVER(__ops)						\

static struct dsa_tag_driver DSA_TAG_DRIVER_NAME(__ops) = {		\

	.ops = &__ops,							\

}



/**

 * module_dsa_tag_driver() - Helper macro for registering a single DSA tag

 * driver

 * @__ops: Single tag driver structures

 *

 * Helper macro for DSA tag drivers which do not do anything special

 * in module init/exit. Each module may only use this macro once, and

 * calling it replaces module_init() and module_exit().

 */

#define module_dsa_tag_driver(__ops)					\

DSA_TAG_DRIVER(__ops);							\

									\

static struct dsa_tag_driver *dsa_tag_driver_array[] =	{		\

	&DSA_TAG_DRIVER_NAME(__ops)					\

};									\

module_dsa_tag_drivers(dsa_tag_driver_array)

#endif

net/dsa/dsa.c

+6 −4
Original line number Diff line number Diff line
@@ -79,16 +79,18 @@ const char *dsa_tag_protocol_to_str(const struct dsa_device_ops *ops) 
/* Function takes a reference on the module owning the tagger,

 * so dsa_tag_driver_put must be called afterwards.

 */

const struct dsa_device_ops *dsa_find_tagger_by_name(const char *buf)

const struct dsa_device_ops *dsa_tag_driver_get_by_name(const char *name)

{

	const struct dsa_device_ops *ops = ERR_PTR(-ENOPROTOOPT);

	struct dsa_tag_driver *dsa_tag_driver;



	request_module("%s%s", DSA_TAG_DRIVER_ALIAS, name);



	mutex_lock(&dsa_tag_drivers_lock);

	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {

		const struct dsa_device_ops *tmp = dsa_tag_driver->ops;



		if (!sysfs_streq(buf, tmp->name))

		if (strcmp(name, tmp->name))

			continue;



		if (!try_module_get(dsa_tag_driver->owner))
@@ -102,13 +104,13 @@ const struct dsa_device_ops *dsa_find_tagger_by_name(const char *buf) 
	return ops;

}



const struct dsa_device_ops *dsa_tag_driver_get(int tag_protocol)

const struct dsa_device_ops *dsa_tag_driver_get_by_id(int tag_protocol)

{

	struct dsa_tag_driver *dsa_tag_driver;

	const struct dsa_device_ops *ops;

	bool found = false;



	request_module("%s%d", DSA_TAG_DRIVER_ALIAS, tag_protocol);

	request_module("%sid-%d", DSA_TAG_DRIVER_ALIAS, tag_protocol);



	mutex_lock(&dsa_tag_drivers_lock);

	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {

net/dsa/dsa2.c

+2 −2
Original line number Diff line number Diff line
@@ -1431,7 +1431,7 @@ static int dsa_port_parse_cpu(struct dsa_port *dp, struct net_device *master, 
			return -EINVAL;

		}



		tag_ops = dsa_find_tagger_by_name(user_protocol);

		tag_ops = dsa_tag_driver_get_by_name(user_protocol);

		if (IS_ERR(tag_ops)) {

			dev_warn(ds->dev,

				 "Failed to find a tagging driver for protocol %s, using default\n",
@@ -1441,7 +1441,7 @@ static int dsa_port_parse_cpu(struct dsa_port *dp, struct net_device *master, 
	}



	if (!tag_ops)

		tag_ops = dsa_tag_driver_get(default_proto);

		tag_ops = dsa_tag_driver_get_by_id(default_proto);



	if (IS_ERR(tag_ops)) {

		if (PTR_ERR(tag_ops) == -ENOPROTOOPT)

net/dsa/dsa_priv.h

+77 −2
Original line number Diff line number Diff line
@@ -17,6 +17,81 @@ 


#define DSA_MAX_NUM_OFFLOADING_BRIDGES		BITS_PER_LONG



/* Create 2 modaliases per tagging protocol, one to auto-load the module

 * given the ID reported by get_tag_protocol(), and the other by name.

 */

#define DSA_TAG_DRIVER_ALIAS "dsa_tag:"

#define MODULE_ALIAS_DSA_TAG_DRIVER(__proto, __name) \

	MODULE_ALIAS(DSA_TAG_DRIVER_ALIAS __name); \

	MODULE_ALIAS(DSA_TAG_DRIVER_ALIAS "id-" \

		     __stringify(__proto##_VALUE))



struct dsa_tag_driver {

	const struct dsa_device_ops *ops;

	struct list_head list;

	struct module *owner;

};



void dsa_tag_drivers_register(struct dsa_tag_driver *dsa_tag_driver_array[],

			      unsigned int count,

			      struct module *owner);

void dsa_tag_drivers_unregister(struct dsa_tag_driver *dsa_tag_driver_array[],

				unsigned int count);



#define dsa_tag_driver_module_drivers(__dsa_tag_drivers_array, __count)	\

static int __init dsa_tag_driver_module_init(void)			\

{									\

	dsa_tag_drivers_register(__dsa_tag_drivers_array, __count,	\

				 THIS_MODULE);				\

	return 0;							\

}									\

module_init(dsa_tag_driver_module_init);				\

									\

static void __exit dsa_tag_driver_module_exit(void)			\

{									\

	dsa_tag_drivers_unregister(__dsa_tag_drivers_array, __count);	\

}									\

module_exit(dsa_tag_driver_module_exit)



/**

 * module_dsa_tag_drivers() - Helper macro for registering DSA tag

 * drivers

 * @__ops_array: Array of tag driver structures

 *

 * Helper macro for DSA tag drivers which do not do anything special

 * in module init/exit. Each module may only use this macro once, and

 * calling it replaces module_init() and module_exit().

 */

#define module_dsa_tag_drivers(__ops_array)				\

dsa_tag_driver_module_drivers(__ops_array, ARRAY_SIZE(__ops_array))



#define DSA_TAG_DRIVER_NAME(__ops) dsa_tag_driver ## _ ## __ops



/* Create a static structure we can build a linked list of dsa_tag

 * drivers

 */

#define DSA_TAG_DRIVER(__ops)						\

static struct dsa_tag_driver DSA_TAG_DRIVER_NAME(__ops) = {		\

	.ops = &__ops,							\

}



/**

 * module_dsa_tag_driver() - Helper macro for registering a single DSA tag

 * driver

 * @__ops: Single tag driver structures

 *

 * Helper macro for DSA tag drivers which do not do anything special

 * in module init/exit. Each module may only use this macro once, and

 * calling it replaces module_init() and module_exit().

 */

#define module_dsa_tag_driver(__ops)					\

DSA_TAG_DRIVER(__ops);							\

									\

static struct dsa_tag_driver *dsa_tag_driver_array[] =	{		\

	&DSA_TAG_DRIVER_NAME(__ops)					\

};									\

module_dsa_tag_drivers(dsa_tag_driver_array)



enum {

	DSA_NOTIFIER_AGEING_TIME,

	DSA_NOTIFIER_BRIDGE_JOIN,
@@ -168,9 +243,9 @@ struct dsa_slave_priv { 
};



/* dsa.c */

const struct dsa_device_ops *dsa_tag_driver_get(int tag_protocol);

const struct dsa_device_ops *dsa_tag_driver_get_by_id(int tag_protocol);

const struct dsa_device_ops *dsa_tag_driver_get_by_name(const char *name);

void dsa_tag_driver_put(const struct dsa_device_ops *ops);

const struct dsa_device_ops *dsa_find_tagger_by_name(const char *buf);



bool dsa_db_equal(const struct dsa_db *a, const struct dsa_db *b);

net/dsa/master.c

+13 −2
Original line number Diff line number Diff line
@@ -299,13 +299,24 @@ static ssize_t tagging_store(struct device *d, struct device_attribute *attr, 
			     const char *buf, size_t count)

{

	const struct dsa_device_ops *new_tag_ops, *old_tag_ops;

	const char *end = strchrnul(buf, '\n'), *name;

	struct net_device *dev = to_net_dev(d);

	struct dsa_port *cpu_dp = dev->dsa_ptr;

	size_t len = end - buf;

	int err;



	/* Empty string passed */

	if (!len)

		return -ENOPROTOOPT;



	name = kstrndup(buf, len, GFP_KERNEL);

	if (!name)

		return -ENOMEM;



	old_tag_ops = cpu_dp->tag_ops;

	new_tag_ops = dsa_find_tagger_by_name(buf);

	/* Bad tagger name, or module is not loaded? */

	new_tag_ops = dsa_tag_driver_get_by_name(name);

	kfree(name);

	/* Bad tagger name? */

	if (IS_ERR(new_tag_ops))

		return PTR_ERR(new_tag_ops);