Commit 94793a56 authored by Vladimir Oltean's avatar Vladimir Oltean Committed by Jakub Kicinski
Browse files

net: dsa: provide a second modalias to tag proto drivers based on their name 



Currently, tagging protocol drivers have a modalias of
"dsa_tag:id-<number>", where the number is one of DSA_TAG_PROTO_*_VALUE.

This modalias makes it possible for the request_module() call in
dsa_tag_driver_get() to work, given the input it has - an integer
returned by ds->ops->get_tag_protocol().

It is also possible to change tagging protocols at (pseudo-)runtime, via
sysfs or via device tree, and this works via the name string of the
tagging protocol rather than via its id (DSA_TAG_PROTO_*_VALUE).

In the latter case, there is no request_module() call, because there is
no association that the DSA core has between the string name and the ID,
to construct the modalias. The module is simply assumed to have been
inserted. This is actually slightly problematic when the tagging
protocol change should take place at probe time, since it's expected
that the dependency module should get autoloaded.

For this purpose, let's introduce a second modalias, so that the DSA
core can call request_module() by name. There is no reason to make the
modalias by name optional, so just modify the MODULE_ALIAS_DSA_TAG_DRIVER()
macro to take both the ID and the name as arguments, and generate two
modaliases behind the scenes.

Suggested-by: default avatarMichael Walle <michael@walle.cc>
Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Michael Walle <michael@walle.cc> # on kontron-sl28 w/ ocelot_8021q
Tested-by: default avatarMichael Walle <michael@walle.cc>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 2610937d

net/dsa/dsa_priv.h

+5 −1
Original line number Diff line number Diff line
@@ -17,8 +17,12 @@ 


#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) \

#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))

net/dsa/tag_ar9331.c

+4 −2
Original line number Diff line number Diff line
@@ -9,6 +9,8 @@ 


#include "dsa_priv.h"



#define AR9331_NAME			"ar9331"



#define AR9331_HDR_LEN			2

#define AR9331_HDR_VERSION		1
@@ -80,7 +82,7 @@ static struct sk_buff *ar9331_tag_rcv(struct sk_buff *skb, 
}



static const struct dsa_device_ops ar9331_netdev_ops = {

	.name	= "ar9331",

	.name	= AR9331_NAME,

	.proto	= DSA_TAG_PROTO_AR9331,

	.xmit	= ar9331_tag_xmit,

	.rcv	= ar9331_tag_rcv,
@@ -88,5 +90,5 @@ static const struct dsa_device_ops ar9331_netdev_ops = { 
};



MODULE_LICENSE("GPL v2");

MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_AR9331);

MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_AR9331, AR9331_NAME);

module_dsa_tag_driver(ar9331_netdev_ops);

net/dsa/tag_brcm.c

+10 −6
Original line number Diff line number Diff line
@@ -12,6 +12,10 @@ 


#include "dsa_priv.h"



#define BRCM_NAME		"brcm"

#define BRCM_LEGACY_NAME	"brcm-legacy"

#define BRCM_PREPEND_NAME	"brcm-prepend"



/* Legacy Broadcom tag (6 bytes) */

#define BRCM_LEG_TAG_LEN	6
@@ -196,7 +200,7 @@ static struct sk_buff *brcm_tag_rcv(struct sk_buff *skb, struct net_device *dev) 
}



static const struct dsa_device_ops brcm_netdev_ops = {

	.name	= "brcm",

	.name	= BRCM_NAME,

	.proto	= DSA_TAG_PROTO_BRCM,

	.xmit	= brcm_tag_xmit,

	.rcv	= brcm_tag_rcv,
@@ -204,7 +208,7 @@ static const struct dsa_device_ops brcm_netdev_ops = { 
};



DSA_TAG_DRIVER(brcm_netdev_ops);

MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM);

MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM, BRCM_NAME);

#endif



#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_LEGACY)
@@ -273,7 +277,7 @@ static struct sk_buff *brcm_leg_tag_rcv(struct sk_buff *skb, 
}



static const struct dsa_device_ops brcm_legacy_netdev_ops = {

	.name = "brcm-legacy",

	.name = BRCM_LEGACY_NAME,

	.proto = DSA_TAG_PROTO_BRCM_LEGACY,

	.xmit = brcm_leg_tag_xmit,

	.rcv = brcm_leg_tag_rcv,
@@ -281,7 +285,7 @@ static const struct dsa_device_ops brcm_legacy_netdev_ops = { 
};



DSA_TAG_DRIVER(brcm_legacy_netdev_ops);

MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM_LEGACY);

MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM_LEGACY, BRCM_LEGACY_NAME);

#endif /* CONFIG_NET_DSA_TAG_BRCM_LEGACY */



#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_PREPEND)
@@ -300,7 +304,7 @@ static struct sk_buff *brcm_tag_rcv_prepend(struct sk_buff *skb, 
}



static const struct dsa_device_ops brcm_prepend_netdev_ops = {

	.name	= "brcm-prepend",

	.name	= BRCM_PREPEND_NAME,

	.proto	= DSA_TAG_PROTO_BRCM_PREPEND,

	.xmit	= brcm_tag_xmit_prepend,

	.rcv	= brcm_tag_rcv_prepend,
@@ -308,7 +312,7 @@ static const struct dsa_device_ops brcm_prepend_netdev_ops = { 
};



DSA_TAG_DRIVER(brcm_prepend_netdev_ops);

MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM_PREPEND);

MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM_PREPEND, BRCM_PREPEND_NAME);

#endif



static struct dsa_tag_driver *dsa_tag_driver_array[] =	{

net/dsa/tag_dsa.c

+7 −4
Original line number Diff line number Diff line
@@ -52,6 +52,9 @@ 


#include "dsa_priv.h"



#define DSA_NAME	"dsa"

#define EDSA_NAME	"edsa"



#define DSA_HLEN	4



/**
@@ -339,7 +342,7 @@ static struct sk_buff *dsa_rcv(struct sk_buff *skb, struct net_device *dev) 
}



static const struct dsa_device_ops dsa_netdev_ops = {

	.name	  = "dsa",

	.name	  = DSA_NAME,

	.proto	  = DSA_TAG_PROTO_DSA,

	.xmit	  = dsa_xmit,

	.rcv	  = dsa_rcv,
@@ -347,7 +350,7 @@ static const struct dsa_device_ops dsa_netdev_ops = { 
};



DSA_TAG_DRIVER(dsa_netdev_ops);

MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_DSA);

MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_DSA, DSA_NAME);

#endif	/* CONFIG_NET_DSA_TAG_DSA */



#if IS_ENABLED(CONFIG_NET_DSA_TAG_EDSA)
@@ -381,7 +384,7 @@ static struct sk_buff *edsa_rcv(struct sk_buff *skb, struct net_device *dev) 
}



static const struct dsa_device_ops edsa_netdev_ops = {

	.name	  = "edsa",

	.name	  = EDSA_NAME,

	.proto	  = DSA_TAG_PROTO_EDSA,

	.xmit	  = edsa_xmit,

	.rcv	  = edsa_rcv,
@@ -389,7 +392,7 @@ static const struct dsa_device_ops edsa_netdev_ops = { 
};



DSA_TAG_DRIVER(edsa_netdev_ops);

MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_EDSA);

MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_EDSA, EDSA_NAME);

#endif	/* CONFIG_NET_DSA_TAG_EDSA */



static struct dsa_tag_driver *dsa_tag_drivers[] = {

net/dsa/tag_gswip.c

+4 −2
Original line number Diff line number Diff line
@@ -12,6 +12,8 @@ 


#include "dsa_priv.h"



#define GSWIP_NAME			"gswip"



#define GSWIP_TX_HEADER_LEN		4



/* special tag in TX path header */
@@ -98,7 +100,7 @@ static struct sk_buff *gswip_tag_rcv(struct sk_buff *skb, 
}



static const struct dsa_device_ops gswip_netdev_ops = {

	.name = "gswip",

	.name = GSWIP_NAME,

	.proto	= DSA_TAG_PROTO_GSWIP,

	.xmit = gswip_tag_xmit,

	.rcv = gswip_tag_rcv,
@@ -106,6 +108,6 @@ static const struct dsa_device_ops gswip_netdev_ops = { 
};



MODULE_LICENSE("GPL");

MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_GSWIP);

MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_GSWIP, GSWIP_NAME);



module_dsa_tag_driver(gswip_netdev_ops);