[PATCH RFC net-next 1/3] net: dsa: allow for multiple CPU ports
From: Ansuel Smith
Date: Sun Apr 11 2021 - 11:04:08 EST
Allow for multiple CPU ports in a DSA switch tree. By default the first
CPU port is assigned mimic the original assignement logic. A DSA driver
can define a function to declare a preferred CPU port based on the
provided port. If the function doesn't have a preferred port the CPU
port is assigned using a round-robin way starting from the last assigned
CPU port.
Examples:
There are two CPU port but no port_get_preferred_cpu is provided:
- The old logic is used. Every port is assigned to the first cpu port.
There are two CPU port but the port_get_preferred_cpu return -1:
- The port is assigned using a round-robin way since no preference is
provided.
There are two CPU port and the port_get_preferred_cpu define only one
port and the rest with -1: (wan port with CPU1 and the rest no
preference)
lan1 <-> eth0
lan2 <-> eth1
lan3 <-> eth0
lan4 <-> eth1
wan <-> eth1
There are two CPU port and the port_get_preferred assign a preference
for every port: (wan port with CPU1 everything else CPU0)
lan1 <-> eth0
lan2 <-> eth0
lan3 <-> eth0
lan4 <-> eth0
wan <-> eth1
Signed-off-by: Marek Behún <marek.behun@xxxxxx>
Signed-off-by: Ansuel Smith <ansuelsmth@xxxxxxxxx>
---
include/net/dsa.h | 7 +++++
net/dsa/dsa2.c | 66 +++++++++++++++++++++++++++++++++--------------
2 files changed, 54 insertions(+), 19 deletions(-)
diff --git a/include/net/dsa.h b/include/net/dsa.h
index d71b1acd9c3e..3d3e936bda4c 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -523,6 +523,13 @@ struct dsa_switch_ops {
void (*teardown)(struct dsa_switch *ds);
u32 (*get_phy_flags)(struct dsa_switch *ds, int port);
+ /*
+ * Get preferred CPU port for the provided port.
+ * Return -1 if there isn't a preferred CPU port, a round-robin logic
+ * is used to chose the CPU port to link to the provided port.
+ */
+ int (*port_get_preferred_cpu)(struct dsa_switch *ds, int port);
+
/*
* Access to the switch's PHY registers.
*/
diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index d142eb2b288b..d3b92499f006 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -315,10 +315,17 @@ static bool dsa_tree_setup_routing_table(struct dsa_switch_tree *dst)
return complete;
}
-static struct dsa_port *dsa_tree_find_first_cpu(struct dsa_switch_tree *dst)
+static struct dsa_port *dsa_tree_find_next_cpu_port(struct dsa_switch_tree *dst,
+ struct dsa_port *cpu_dp)
{
- struct dsa_port *dp;
+ struct dsa_port *dp = cpu_dp;
+
+ if (dp)
+ list_for_each_entry_from(dp, &dst->ports, list)
+ if (dsa_port_is_cpu(dp))
+ return dp;
+ /* If another CPU port can't be found, try from the start */
list_for_each_entry(dp, &dst->ports, list)
if (dsa_port_is_cpu(dp))
return dp;
@@ -326,25 +333,40 @@ static struct dsa_port *dsa_tree_find_first_cpu(struct dsa_switch_tree *dst)
return NULL;
}
-static int dsa_tree_setup_default_cpu(struct dsa_switch_tree *dst)
+static int dsa_tree_setup_default_cpus(struct dsa_switch_tree *dst)
{
- struct dsa_port *cpu_dp, *dp;
+ struct dsa_port *dp, *cpu_dp = NULL, *first_cpu_dp;
+ int cpu_port;
- cpu_dp = dsa_tree_find_first_cpu(dst);
- if (!cpu_dp) {
+ first_cpu_dp = dsa_tree_find_next_cpu_port(dst, NULL);
+ if (!first_cpu_dp) {
pr_err("DSA: tree %d has no CPU port\n", dst->index);
return -EINVAL;
}
- /* Assign the default CPU port to all ports of the fabric */
list_for_each_entry(dp, &dst->ports, list)
- if (dsa_port_is_user(dp) || dsa_port_is_dsa(dp))
- dp->cpu_dp = cpu_dp;
+ if (dsa_port_is_user(dp) || dsa_port_is_dsa(dp)) {
+ /* Check if the driver advice a CPU port for the current port */
+ if (dp->ds->ops->port_get_preferred_cpu) {
+ cpu_port = dp->ds->ops->port_get_preferred_cpu(dp->ds, dp->index);
+
+ /* If the driver doesn't have a preferred port,
+ * assing in round-robin way.
+ */
+ if (cpu_port < 0)
+ cpu_dp = dsa_tree_find_next_cpu_port(dst, cpu_dp);
+ else
+ cpu_dp = dsa_to_port(dp->ds, cpu_port);
+ }
+
+ /* If a cpu port is not chosen, assign the first one by default */
+ dp->cpu_dp = cpu_dp ? cpu_dp : first_cpu_dp;
+ }
return 0;
}
-static void dsa_tree_teardown_default_cpu(struct dsa_switch_tree *dst)
+static void dsa_tree_teardown_default_cpus(struct dsa_switch_tree *dst)
{
struct dsa_port *dp;
@@ -822,7 +844,7 @@ static void dsa_tree_teardown_switches(struct dsa_switch_tree *dst)
dsa_switch_teardown(dp->ds);
}
-static int dsa_tree_setup_master(struct dsa_switch_tree *dst)
+static int dsa_tree_setup_masters(struct dsa_switch_tree *dst)
{
struct dsa_port *dp;
int err;
@@ -831,14 +853,20 @@ static int dsa_tree_setup_master(struct dsa_switch_tree *dst)
if (dsa_port_is_cpu(dp)) {
err = dsa_master_setup(dp->master, dp);
if (err)
- return err;
+ goto teardown;
}
}
return 0;
+teardown:
+ list_for_each_entry_from_reverse(dp, &dst->ports, list)
+ if (dsa_port_is_cpu(dp))
+ dsa_master_teardown(dp->master);
+
+ return err;
}
-static void dsa_tree_teardown_master(struct dsa_switch_tree *dst)
+static void dsa_tree_teardown_masters(struct dsa_switch_tree *dst)
{
struct dsa_port *dp;
@@ -888,7 +916,7 @@ static int dsa_tree_setup(struct dsa_switch_tree *dst)
if (!complete)
return 0;
- err = dsa_tree_setup_default_cpu(dst);
+ err = dsa_tree_setup_default_cpus(dst);
if (err)
return err;
@@ -896,7 +924,7 @@ static int dsa_tree_setup(struct dsa_switch_tree *dst)
if (err)
goto teardown_default_cpu;
- err = dsa_tree_setup_master(dst);
+ err = dsa_tree_setup_masters(dst);
if (err)
goto teardown_switches;
@@ -911,11 +939,11 @@ static int dsa_tree_setup(struct dsa_switch_tree *dst)
return 0;
teardown_master:
- dsa_tree_teardown_master(dst);
+ dsa_tree_teardown_masters(dst);
teardown_switches:
dsa_tree_teardown_switches(dst);
teardown_default_cpu:
- dsa_tree_teardown_default_cpu(dst);
+ dsa_tree_teardown_default_cpus(dst);
return err;
}
@@ -929,11 +957,11 @@ static void dsa_tree_teardown(struct dsa_switch_tree *dst)
dsa_tree_teardown_lags(dst);
- dsa_tree_teardown_master(dst);
+ dsa_tree_teardown_masters(dst);
dsa_tree_teardown_switches(dst);
- dsa_tree_teardown_default_cpu(dst);
+ dsa_tree_teardown_default_cpus(dst);
list_for_each_entry_safe(dl, next, &dst->rtable, list) {
list_del(&dl->list);
--
2.30.2