[PATCH net-next 02/16] net: dsa: add ports list in the switch fabric

Vivien Didelot
2019-10-20T03:20:16Z

Add a list of switch ports within the switch fabric. This will help the
lookup of a port inside the whole fabric, and it is the first step
towards supporting multiple CPU ports, before deprecating the usage of
the unique dst->cpu_dp pointer.

In preparation for a future allocation of the dsa_port structures,
return -ENOMEM in case no structure is returned, even though this
error cannot be reached yet.

Signed-off-by: Vivien Didelot <vivien.didelot@gmail.com>
---
include/net/dsa.h | 5 +++++
net/dsa/dsa2.c | 48 +++++++++++++++++++++++++++++++++++++++++------
2 files changed, 47 insertions(+), 6 deletions(-)

diff --git a/include/net/dsa.h b/include/net/dsa.h
index 2e4fe2f8962b..6ff6dfcdc61d 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -125,6 +125,9 @@ struct dsa_switch_tree {
*/
struct dsa_port *cpu_dp;

+ /* List of switch ports */
+ struct list_head ports;
+
/*
* Data for the individual switch chips.
*/
@@ -195,6 +198,8 @@ struct dsa_port {
struct work_struct xmit_work;
struct sk_buff_head xmit_queue;

+ struct list_head list;
+
/*
* Give the switch driver somewhere to hang its per-port private data
* structures (accessible from the tagger).
diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index 1716535167ee..b6536641ac99 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -45,6 +45,8 @@ static struct dsa_switch_tree *dsa_tree_alloc(int index)

dst->index = index;

+ INIT_LIST_HEAD(&dst->ports);
+
INIT_LIST_HEAD(&dst->list);
list_add_tail(&dst->list, &dsa_tree_list);

@@ -616,6 +618,22 @@ static int dsa_tree_add_switch(struct dsa_switch_tree *dst,
return err;
}

+static struct dsa_port *dsa_port_touch(struct dsa_switch *ds, int index)
+{
+ struct dsa_switch_tree *dst = ds->dst;
+ struct dsa_port *dp;
+
+ dp = &ds->ports[index];
+
+ dp->ds = ds;
+ dp->index = index;
+
+ INIT_LIST_HEAD(&dp->list);
+ list_add(&dp->list, &dst->ports);
+
+ return dp;
+}
+
static int dsa_port_parse_user(struct dsa_port *dp, const char *name)
{
if (!name)
@@ -742,6 +760,20 @@ static int dsa_switch_parse_member_of(struct dsa_switch *ds,
return 0;
}

+static int dsa_switch_touch_ports(struct dsa_switch *ds)
+{
+ struct dsa_port *dp;
+ int port;
+
+ for (port = 0; port < ds->num_ports; port++) {
+ dp = dsa_port_touch(ds, port);
+ if (!dp)
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
static int dsa_switch_parse_of(struct dsa_switch *ds, struct device_node *dn)
{
int err;
@@ -750,6 +782,10 @@ static int dsa_switch_parse_of(struct dsa_switch *ds, struct device_node *dn)
if (err)
return err;

+ err = dsa_switch_touch_ports(ds);
+ if (err)
+ return err;
+
return dsa_switch_parse_ports_of(ds, dn);
}

@@ -807,6 +843,8 @@ static int dsa_switch_parse_ports(struct dsa_switch *ds,

static int dsa_switch_parse(struct dsa_switch *ds, struct dsa_chip_data *cd)
{
+ int err;
+
ds->cd = cd;

/* We don't support interconnected switches nor multiple trees via
@@ -817,6 +855,10 @@ static int dsa_switch_parse(struct dsa_switch *ds, struct dsa_chip_data *cd)
if (!ds->dst)
return -ENOMEM;

+ err = dsa_switch_touch_ports(ds);
+ if (err)
+ return err;
+
return dsa_switch_parse_ports(ds, cd);
}

@@ -849,7 +891,6 @@ static int dsa_switch_probe(struct dsa_switch *ds)
struct dsa_switch *dsa_switch_alloc(struct device *dev, size_t n)
{
struct dsa_switch *ds;
- int i;

ds = devm_kzalloc(dev, struct_size(ds, ports, n), GFP_KERNEL);
if (!ds)
@@ -858,11 +899,6 @@ struct dsa_switch *dsa_switch_alloc(struct device *dev, size_t n)
ds->dev = dev;
ds->num_ports = n;

- for (i = 0; i < ds->num_ports; ++i) {
- ds->ports[i].index = i;
- ds->ports[i].ds = ds;
- }
-
return ds;
}
EXPORT_SYMBOL_GPL(dsa_switch_alloc);
--
2.23.0