net: dsa: loop: Implement ethtool statistics

When a DSA driver implements ethtool statistics, we also override the
master network device's ethtool statistics with the CPU port's
statistics and this has proven to be a possible source of bugs in the
past. Enhance the dsa_loop.c driver to provide statistics under the
forme of ok/error reads and writes from the per-port PHY read/writes.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 77 insertions, 2 deletions

diff --git a/drivers/net/dsa/dsa_loop.c b/drivers/net/dsa/dsa_loop.c
index fb888593c2e9..fdd8f3872102 100644
--- a/drivers/net/dsa/dsa_loop.c
+++ b/drivers/net/dsa/dsa_loop.c
@@ -14,6 +14,7 @@
 #include <linux/phy.h>
 #include <linux/phy_fixed.h>
 #include <linux/export.h>
+#include <linux/ethtool.h>
 #include <linux/workqueue.h>
 #include <linux/module.h>
 #include <linux/if_bridge.h>
@@ -26,6 +27,30 @@ struct dsa_loop_vlan {
         u16 untagged;
 };
 
+struct dsa_loop_mib_entry {
+        char name[ETH_GSTRING_LEN];
+        unsigned long val;
+};
+
+enum dsa_loop_mib_counters {
+        DSA_LOOP_PHY_READ_OK,
+        DSA_LOOP_PHY_READ_ERR,
+        DSA_LOOP_PHY_WRITE_OK,
+        DSA_LOOP_PHY_WRITE_ERR,
+        __DSA_LOOP_CNT_MAX,
+};
+
+static struct dsa_loop_mib_entry dsa_loop_mibs[] = {
+        [DSA_LOOP_PHY_READ_OK]  = { "phy_read_ok", },
+        [DSA_LOOP_PHY_READ_ERR] = { "phy_read_err", },
+        [DSA_LOOP_PHY_WRITE_OK] = { "phy_write_ok", },
+        [DSA_LOOP_PHY_WRITE_ERR] = { "phy_write_err", },
+};
+
+struct dsa_loop_port {
+        struct dsa_loop_mib_entry mib[__DSA_LOOP_CNT_MAX];
+};
+
 #define DSA_LOOP_VLANS  5
 
 struct dsa_loop_priv {
@@ -33,6 +58,7 @@ struct dsa_loop_priv {
         unsigned int    port_base;
         struct dsa_loop_vlan vlans[DSA_LOOP_VLANS];
         struct net_device *netdev;
+        struct dsa_loop_port ports[DSA_MAX_PORTS];
         u16 pvid;
 };
 
@@ -47,11 +73,43 @@ static enum dsa_tag_protocol dsa_loop_get_protocol(struct dsa_switch *ds)
 
 static int dsa_loop_setup(struct dsa_switch *ds)
 {
+        struct dsa_loop_priv *ps = ds->priv;
+        unsigned int i;
+
+        for (i = 0; i < ds->num_ports; i++)
+                memcpy(ps->ports[i].mib, dsa_loop_mibs,
+                       sizeof(dsa_loop_mibs));
+
         dev_dbg(ds->dev, "%s\n", __func__);
 
         return 0;
 }
 
+static int dsa_loop_get_sset_count(struct dsa_switch *ds)
+{
+        return __DSA_LOOP_CNT_MAX;
+}
+
+static void dsa_loop_get_strings(struct dsa_switch *ds, int port, uint8_t *data)
+{
+        struct dsa_loop_priv *ps = ds->priv;
+        unsigned int i;
+
+        for (i = 0; i < __DSA_LOOP_CNT_MAX; i++)
+                memcpy(data + i * ETH_GSTRING_LEN,
+                       ps->ports[port].mib[i].name, ETH_GSTRING_LEN);
+}
+
+static void dsa_loop_get_ethtool_stats(struct dsa_switch *ds, int port,
+                                       uint64_t *data)
+{
+        struct dsa_loop_priv *ps = ds->priv;
+        unsigned int i;
+
+        for (i = 0; i < __DSA_LOOP_CNT_MAX; i++)
+                data[i] = ps->ports[port].mib[i].val;
+}
+
 static int dsa_loop_set_addr(struct dsa_switch *ds, u8 *addr)
 {
         dev_dbg(ds->dev, "%s\n", __func__);
@@ -63,10 +121,17 @@ static int dsa_loop_phy_read(struct dsa_switch *ds, int port, int regnum)
 {
         struct dsa_loop_priv *ps = ds->priv;
         struct mii_bus *bus = ps->bus;
+        int ret;
 
         dev_dbg(ds->dev, "%s\n", __func__);
 
-        return mdiobus_read_nested(bus, ps->port_base + port, regnum);
+        ret = mdiobus_read_nested(bus, ps->port_base + port, regnum);
+        if (ret < 0)
+                ps->ports[port].mib[DSA_LOOP_PHY_READ_ERR].val++;
+        else
+                ps->ports[port].mib[DSA_LOOP_PHY_READ_OK].val++;
+
+        return ret;
 }
 
 static int dsa_loop_phy_write(struct dsa_switch *ds, int port,
@@ -74,10 +139,17 @@ static int dsa_loop_phy_write(struct dsa_switch *ds, int port,
 {
         struct dsa_loop_priv *ps = ds->priv;
         struct mii_bus *bus = ps->bus;
+        int ret;
 
         dev_dbg(ds->dev, "%s\n", __func__);
 
-        return mdiobus_write_nested(bus, ps->port_base + port, regnum, value);
+        ret = mdiobus_write_nested(bus, ps->port_base + port, regnum, value);
+        if (ret < 0)
+                ps->ports[port].mib[DSA_LOOP_PHY_WRITE_ERR].val++;
+        else
+                ps->ports[port].mib[DSA_LOOP_PHY_WRITE_OK].val++;
+
+        return ret;
 }
 
 static int dsa_loop_port_bridge_join(struct dsa_switch *ds, int port,
@@ -225,6 +297,9 @@ static int dsa_loop_port_vlan_dump(struct dsa_switch *ds, int port,
 static struct dsa_switch_ops dsa_loop_driver = {
         .get_tag_protocol       = dsa_loop_get_protocol,
         .setup                  = dsa_loop_setup,
+        .get_strings            = dsa_loop_get_strings,
+        .get_ethtool_stats      = dsa_loop_get_ethtool_stats,
+        .get_sset_count         = dsa_loop_get_sset_count,
         .set_addr               = dsa_loop_set_addr,
         .phy_read               = dsa_loop_phy_read,
         .phy_write              = dsa_loop_phy_write,