net: dsa: felix: convert to the new .change_tag_protocol DSA API

In expectation of the new tag_ocelot_8021q tagger implementation, we
need to be able to do runtime switchover between one tagger and another.
So we must structure the existing code for the current NPI-based tagger
in a certain way.

We move the felix_npi_port_init function in expectation of the future
driver configuration necessary for tag_ocelot_8021q: we would like to
not have the NPI-related bits interspersed with the tag_8021q bits.

The conversion from this:

	ocelot_write_rix(ocelot,
			 ANA_PGID_PGID_PGID(GENMASK(ocelot->num_phys_ports, 0)),
			 ANA_PGID_PGID, PGID_UC);

to this:

	cpu_flood = ANA_PGID_PGID_PGID(BIT(ocelot->num_phys_ports));
	ocelot_rmw_rix(ocelot, cpu_flood, cpu_flood, ANA_PGID_PGID, PGID_UC);

is perhaps non-trivial, but is nonetheless non-functional. The PGID_UC
(replicator for unknown unicast) is already configured out of hardware
reset to flood to all ports except ocelot->num_phys_ports (the CPU port
module). All we change is that we use a read-modify-write to only add
the CPU port module to the unknown unicast replicator, as opposed to
doing a full write to the register.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/dsa/ocelot/felix.c b/drivers/net/dsa/ocelot/felix.c
index 054e57dd4383984227b49dd192f85c47e6371522..af3cee8762ce03e8406dfdd340ae674ca79490c8 100644 (file)
--- a/drivers/net/dsa/ocelot/felix.c
+++ b/drivers/net/dsa/ocelot/felix.c
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
-/* Copyright 2019 NXP Semiconductors
+/* Copyright 2019-2021 NXP Semiconductors
  *
  * This is an umbrella module for all network switches that are
  * register-compatible with Ocelot and that perform I/O to their host CPU
@@ -24,11 +24,140 @@
 #include <net/dsa.h>
 #include "felix.h"
 
+/* The CPU port module is connected to the Node Processor Interface (NPI). This
+ * is the mode through which frames can be injected from and extracted to an
+ * external CPU, over Ethernet. In NXP SoCs, the "external CPU" is the ARM CPU
+ * running Linux, and this forms a DSA setup together with the enetc or fman
+ * DSA master.
+ */
+static void felix_npi_port_init(struct ocelot *ocelot, int port)
+{
+       ocelot->npi = port;
+
+       ocelot_write(ocelot, QSYS_EXT_CPU_CFG_EXT_CPUQ_MSK_M |
+                    QSYS_EXT_CPU_CFG_EXT_CPU_PORT(port),
+                    QSYS_EXT_CPU_CFG);
+
+       /* NPI port Injection/Extraction configuration */
+       ocelot_fields_write(ocelot, port, SYS_PORT_MODE_INCL_XTR_HDR,
+                           ocelot->npi_xtr_prefix);
+       ocelot_fields_write(ocelot, port, SYS_PORT_MODE_INCL_INJ_HDR,
+                           ocelot->npi_inj_prefix);
+
+       /* Disable transmission of pause frames */
+       ocelot_fields_write(ocelot, port, SYS_PAUSE_CFG_PAUSE_ENA, 0);
+}
+
+static void felix_npi_port_deinit(struct ocelot *ocelot, int port)
+{
+       /* Restore hardware defaults */
+       int unused_port = ocelot->num_phys_ports + 2;
+
+       ocelot->npi = -1;
+
+       ocelot_write(ocelot, QSYS_EXT_CPU_CFG_EXT_CPU_PORT(unused_port),
+                    QSYS_EXT_CPU_CFG);
+
+       ocelot_fields_write(ocelot, port, SYS_PORT_MODE_INCL_XTR_HDR,
+                           OCELOT_TAG_PREFIX_DISABLED);
+       ocelot_fields_write(ocelot, port, SYS_PORT_MODE_INCL_INJ_HDR,
+                           OCELOT_TAG_PREFIX_DISABLED);
+
+       /* Enable transmission of pause frames */
+       ocelot_fields_write(ocelot, port, SYS_PAUSE_CFG_PAUSE_ENA, 1);
+}
+
+static int felix_setup_tag_npi(struct dsa_switch *ds, int cpu)
+{
+       struct ocelot *ocelot = ds->priv;
+       unsigned long cpu_flood;
+
+       felix_npi_port_init(ocelot, cpu);
+
+       /* Include the CPU port module (and indirectly, the NPI port)
+        * in the forwarding mask for unknown unicast - the hardware
+        * default value for ANA_FLOODING_FLD_UNICAST excludes
+        * BIT(ocelot->num_phys_ports), and so does ocelot_init,
+        * since Ocelot relies on whitelisting MAC addresses towards
+        * PGID_CPU.
+        * We do this because DSA does not yet perform RX filtering,
+        * and the NPI port does not perform source address learning,
+        * so traffic sent to Linux is effectively unknown from the
+        * switch's perspective.
+        */
+       cpu_flood = ANA_PGID_PGID_PGID(BIT(ocelot->num_phys_ports));
+       ocelot_rmw_rix(ocelot, cpu_flood, cpu_flood, ANA_PGID_PGID, PGID_UC);
+
+       return 0;
+}
+
+static void felix_teardown_tag_npi(struct dsa_switch *ds, int cpu)
+{
+       struct ocelot *ocelot = ds->priv;
+
+       felix_npi_port_deinit(ocelot, cpu);
+}
+
+static int felix_set_tag_protocol(struct dsa_switch *ds, int cpu,
+                                 enum dsa_tag_protocol proto)
+{
+       int err;
+
+       switch (proto) {
+       case DSA_TAG_PROTO_OCELOT:
+               err = felix_setup_tag_npi(ds, cpu);
+               break;
+       default:
+               err = -EPROTONOSUPPORT;
+       }
+
+       return err;
+}
+
+static void felix_del_tag_protocol(struct dsa_switch *ds, int cpu,
+                                  enum dsa_tag_protocol proto)
+{
+       switch (proto) {
+       case DSA_TAG_PROTO_OCELOT:
+               felix_teardown_tag_npi(ds, cpu);
+               break;
+       default:
+               break;
+       }
+}
+
+static int felix_change_tag_protocol(struct dsa_switch *ds, int cpu,
+                                    enum dsa_tag_protocol proto)
+{
+       struct ocelot *ocelot = ds->priv;
+       struct felix *felix = ocelot_to_felix(ocelot);
+       enum dsa_tag_protocol old_proto = felix->tag_proto;
+       int err;
+
+       if (proto != DSA_TAG_PROTO_OCELOT)
+               return -EPROTONOSUPPORT;
+
+       felix_del_tag_protocol(ds, cpu, old_proto);
+
+       err = felix_set_tag_protocol(ds, cpu, proto);
+       if (err) {
+               felix_set_tag_protocol(ds, cpu, old_proto);
+               return err;
+       }
+
+       felix->tag_proto = proto;
+
+       return 0;
+}
+
 static enum dsa_tag_protocol felix_get_tag_protocol(struct dsa_switch *ds,
                                                    int port,
                                                    enum dsa_tag_protocol mp)
 {
-       return DSA_TAG_PROTO_OCELOT;
+       struct ocelot *ocelot = ds->priv;
+       struct felix *felix = ocelot_to_felix(ocelot);
+
+       return felix->tag_proto;
 }
 
 static int felix_set_ageing_time(struct dsa_switch *ds,
@@ -527,28 +656,6 @@ static int felix_init_structs(struct felix *felix, int num_phys_ports)
        return 0;
 }
 
-/* The CPU port module is connected to the Node Processor Interface (NPI). This
- * is the mode through which frames can be injected from and extracted to an
- * external CPU, over Ethernet.
- */
-static void felix_npi_port_init(struct ocelot *ocelot, int port)
-{
-       ocelot->npi = port;
-
-       ocelot_write(ocelot, QSYS_EXT_CPU_CFG_EXT_CPUQ_MSK_M |
-                    QSYS_EXT_CPU_CFG_EXT_CPU_PORT(port),
-                    QSYS_EXT_CPU_CFG);
-
-       /* NPI port Injection/Extraction configuration */
-       ocelot_fields_write(ocelot, port, SYS_PORT_MODE_INCL_XTR_HDR,
-                           ocelot->npi_xtr_prefix);
-       ocelot_fields_write(ocelot, port, SYS_PORT_MODE_INCL_INJ_HDR,
-                           ocelot->npi_inj_prefix);
-
-       /* Disable transmission of pause frames */
-       ocelot_fields_write(ocelot, port, SYS_PAUSE_CFG_PAUSE_ENA, 0);
-}
-
 /* Hardware initialization done here so that we can allocate structures with
  * devm without fear of dsa_register_switch returning -EPROBE_DEFER and causing
  * us to allocate structures twice (leak memory) and map PCI memory twice
@@ -578,10 +685,10 @@ static int felix_setup(struct dsa_switch *ds)
        }
 
        for (port = 0; port < ds->num_ports; port++) {
-               ocelot_init_port(ocelot, port);
+               if (dsa_is_unused_port(ds, port))
+                       continue;
 
-               if (dsa_is_cpu_port(ds, port))
-                       felix_npi_port_init(ocelot, port);
+               ocelot_init_port(ocelot, port);
 
                /* Set the default QoS Classification based on PCP and DEI
                 * bits of vlan tag.
@@ -593,14 +700,15 @@ static int felix_setup(struct dsa_switch *ds)
        if (err)
                return err;
 
-       /* Include the CPU port module in the forwarding mask for unknown
-        * unicast - the hardware default value for ANA_FLOODING_FLD_UNICAST
-        * excludes BIT(ocelot->num_phys_ports), and so does ocelot_init, since
-        * Ocelot relies on whitelisting MAC addresses towards PGID_CPU.
-        */
-       ocelot_write_rix(ocelot,
-                        ANA_PGID_PGID_PGID(GENMASK(ocelot->num_phys_ports, 0)),
-                        ANA_PGID_PGID, PGID_UC);
+       for (port = 0; port < ds->num_ports; port++) {
+               if (!dsa_is_cpu_port(ds, port))
+                       continue;
+
+               /* The initial tag protocol is NPI which always returns 0, so
+                * there's no real point in checking for errors.
+                */
+               felix_set_tag_protocol(ds, port, felix->tag_proto);
+       }
 
        ds->mtu_enforcement_ingress = true;
        ds->assisted_learning_on_cpu_port = true;
@@ -614,6 +722,13 @@ static void felix_teardown(struct dsa_switch *ds)
        struct felix *felix = ocelot_to_felix(ocelot);
        int port;
 
+       for (port = 0; port < ds->num_ports; port++) {
+               if (!dsa_is_cpu_port(ds, port))
+                       continue;
+
+               felix_del_tag_protocol(ds, port, felix->tag_proto);
+       }
+
        ocelot_devlink_sb_unregister(ocelot);
        ocelot_deinit_timestamp(ocelot);
        ocelot_deinit(ocelot);
@@ -860,6 +975,7 @@ static int felix_sb_occ_tc_port_bind_get(struct dsa_switch *ds, int port,
 
 const struct dsa_switch_ops felix_switch_ops = {
        .get_tag_protocol               = felix_get_tag_protocol,
+       .change_tag_protocol            = felix_change_tag_protocol,
        .setup                          = felix_setup,
        .teardown                       = felix_teardown,
        .set_ageing_time                = felix_set_ageing_time,

diff --git a/drivers/net/dsa/ocelot/felix.h b/drivers/net/dsa/ocelot/felix.h
index 994835cb9307f6036da28f4b9b4ba753d164af97..264b3bbdc4d1f2864ca62b3a91e3894ac834d21f 100644 (file)
--- a/drivers/net/dsa/ocelot/felix.h
+++ b/drivers/net/dsa/ocelot/felix.h
@@ -48,6 +48,7 @@ struct felix {
        struct lynx_pcs                 **pcs;
        resource_size_t                 switch_base;
        resource_size_t                 imdio_base;
+       enum dsa_tag_protocol           tag_proto;
 };
 
 struct net_device *felix_port_to_netdev(struct ocelot *ocelot, int port);

diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c
index f9711e69b8d54aa7d4892b6d7f0755f99934e843..e944868cc120bf7c4665ff28a6ff1d7fb8882c67 100644 (file)
--- a/drivers/net/dsa/ocelot/felix_vsc9959.c
+++ b/drivers/net/dsa/ocelot/felix_vsc9959.c
@@ -1467,6 +1467,7 @@ static int felix_pci_probe(struct pci_dev *pdev,
        ds->ops = &felix_switch_ops;
        ds->priv = ocelot;
        felix->ds = ds;
+       felix->tag_proto = DSA_TAG_PROTO_OCELOT;
 
        err = dsa_register_switch(ds);
        if (err) {

diff --git a/drivers/net/dsa/ocelot/seville_vsc9953.c b/drivers/net/dsa/ocelot/seville_vsc9953.c
index 5e9bfdea50be5d3d4c293779a5cb3e6593ea2b99..512f677a6c1c5682f81fffd893d7a925f2bc0c05 100644 (file)
--- a/drivers/net/dsa/ocelot/seville_vsc9953.c
+++ b/drivers/net/dsa/ocelot/seville_vsc9953.c
@@ -1246,6 +1246,7 @@ static int seville_probe(struct platform_device *pdev)
        ds->ops = &felix_switch_ops;
        ds->priv = ocelot;
        felix->ds = ds;
+       felix->tag_proto = DSA_TAG_PROTO_OCELOT;
 
        err = dsa_register_switch(ds);
        if (err) {