Merge branch 'DSA-mtu'

Vladimir Oltean says:

====================
Configure the MTU on DSA switches

This series adds support for configuring the MTU on front-panel switch
ports, while seamlessly adapting the CPU port and the DSA master to the
largest value plus the tagger overhead.

It also implements bridge MTU auto-normalization within the DSA core, as
resulted after the feedback of the implementation of this feature inside
the bridge driver in v2.

Support was added for quite a number of switches, in the hope that this
series would gain some traction:
 - sja1105
 - felix
 - vsc73xx
 - b53 and rest of the platform

V3 of this series was submitted here:
https://patchwork.ozlabs.org/cover/1262394/

V2 of this series was submitted here:
https://patchwork.ozlabs.org/cover/1261471/

V1 of this series was submitted here:
https://patchwork.ozlabs.org/cover/1199868/
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 25 insertions, 0 deletions

diff --git a/include/linux/brcmphy.h b/include/linux/brcmphy.h
index b475e7f20d28..6462c5447872 100644
--- a/include/linux/brcmphy.h
+++ b/include/linux/brcmphy.h
@@ -79,6 +79,7 @@
 #define MII_BCM54XX_ECR		0x10	/* BCM54xx extended control register */
 #define MII_BCM54XX_ECR_IM	0x1000	/* Interrupt mask */
 #define MII_BCM54XX_ECR_IF	0x0800	/* Interrupt force */
+#define MII_BCM54XX_ECR_FIFOE	0x0001	/* FIFO elasticity */
 
 #define MII_BCM54XX_ESR		0x11	/* BCM54xx extended status register */
 #define MII_BCM54XX_ESR_IS	0x1000	/* Interrupt status */
@@ -119,6 +120,7 @@
 #define MII_BCM54XX_AUXCTL_SHDWSEL_AUXCTL	0x00
 #define MII_BCM54XX_AUXCTL_ACTL_TX_6DB		0x0400
 #define MII_BCM54XX_AUXCTL_ACTL_SMDSP_ENA	0x0800
+#define MII_BCM54XX_AUXCTL_ACTL_EXT_PKT_LEN	0x4000
 
 #define MII_BCM54XX_AUXCTL_SHDWSEL_MISC			0x07
 #define MII_BCM54XX_AUXCTL_SHDWSEL_MISC_WIRESPEED_EN	0x0010
diff --git a/include/net/dsa.h b/include/net/dsa.h
index beeb81a532e3..aeb411e77b9a 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -284,6 +284,12 @@ struct dsa_switch {
 	 */
 	bool			pcs_poll;
 
+	/* For switches that only have the MRU configurable. To ensure the
+	 * configured MTU is not exceeded, normalization of MRU on all bridged
+	 * interfaces is needed.
+	 */
+	bool			mtu_enforcement_ingress;
+
 	size_t num_ports;
 };
 
@@ -579,6 +585,16 @@ struct dsa_switch_ops {
 				     struct devlink_param_gset_ctx *ctx);
 	int	(*devlink_param_set)(struct dsa_switch *ds, u32 id,
 				     struct devlink_param_gset_ctx *ctx);
+
+	/*
+	 * MTU change functionality. Switches can also adjust their MRU through
+	 * this method. By MTU, one understands the SDU (L2 payload) length.
+	 * If the switch needs to account for the DSA tag on the CPU port, this
+	 * method needs to to do so privately.
+	 */
+	int	(*port_change_mtu)(struct dsa_switch *ds, int port,
+				   int new_mtu);
+	int	(*port_max_mtu)(struct dsa_switch *ds, int port);
 };
 
 #define DSA_DEVLINK_PARAM_DRIVER(_id, _name, _type, _cmodes)		\
diff --git a/include/soc/mscc/ocelot.h b/include/soc/mscc/ocelot.h
index 007b584cc431..eadbc2ddfcb5 100644
--- a/include/soc/mscc/ocelot.h
+++ b/include/soc/mscc/ocelot.h
@@ -517,6 +517,11 @@ struct ocelot {
 	 */
 	u8				num_phys_ports;
 
+	int				npi;
+
+	enum ocelot_tag_prefix		inj_prefix;
+	enum ocelot_tag_prefix		xtr_prefix;
+
 	u32				*lags;
 
 	struct list_head		multicast;
@@ -611,6 +616,8 @@ int ocelot_ptp_gettime64(struct ptp_clock_info *ptp, struct timespec64 *ts);
 int ocelot_port_add_txtstamp_skb(struct ocelot_port *ocelot_port,
 				 struct sk_buff *skb);
 void ocelot_get_txtstamp(struct ocelot *ocelot);
+void ocelot_port_set_maxlen(struct ocelot *ocelot, int port, size_t sdu);
+int ocelot_get_max_mtu(struct ocelot *ocelot, int port);
 int ocelot_cls_flower_replace(struct ocelot *ocelot, int port,
 			      struct flow_cls_offload *f, bool ingress);
 int ocelot_cls_flower_destroy(struct ocelot *ocelot, int port,