Subject: [net-next][PATCH v2 2/2] dsa: lan9303: Add 2 ethtool stats

From: Jerry Ray <[email-masked]>
Date: Tue, 15 Nov 2022 10:51:31 -0600

Adding RxDropped and TxDropped counters to the reported statistics.
As these stats are kept by the switch rather than the port instance,
they are indexed differently.

Signed-off-by: Jerry Ray <[email-masked]>
---
v1->v2:
  Split patch into 2 pieces.
  Removed the adding of a module number to the driver.
---
 drivers/net/dsa/lan9303-core.c | 38 ++++++++++++++++++++++++++++------
 1 file changed, 32 insertions(+), 6 deletions(-)

diff --git a/drivers/net/dsa/lan9303-core.c b/drivers/net/dsa/lan9303-core.c
index 80f07bd20593..714a21d7aa0a 100644
--- a/drivers/net/dsa/lan9303-core.c
+++ b/drivers/net/dsa/lan9303-core.c
@@ -177,10 +177,12 @@
 #define LAN9303_SWE_INGRESS_PORT_TYPE 0x1847
 #define  LAN9303_SWE_INGRESS_PORT_TYPE_VLAN 3
 #define LAN9303_BM_CFG 0x1c00
+#define LAN9303_BM_DRP_CNT_SRC_0 0x1c05
 #define LAN9303_BM_EGRSS_PORT_TYPE 0x1c0c
 # define LAN9303_BM_EGRSS_PORT_TYPE_SPECIAL_TAG_PORT2 (BIT(17) | BIT(16))
 # define LAN9303_BM_EGRSS_PORT_TYPE_SPECIAL_TAG_PORT1 (BIT(9) | BIT(8))
 # define LAN9303_BM_EGRSS_PORT_TYPE_SPECIAL_TAG_PORT0 (BIT(1) | BIT(0))
+#define LAN9303_BM_RATE_DRP_CNT_SRC_0 0x1c16
 
 #define LAN9303_SWITCH_PORT_REG(port, reg0) (0x400 * (port) + (reg0))
 
@@ -978,10 +980,16 @@ static const struct lan9303_mib_desc lan9303_mib[] = {
 	{ .offset = LAN9303_MAC_TX_LATECOL_0, .name = "TxLateCol", },
 };
 
+/* Buffer Management Statistics (indexed by port) */
+static const struct lan9303_mib_desc lan9303_switch_mib[] = {
+	{ .offset = LAN9303_BM_RATE_DRP_CNT_SRC_0, .name = "RxDropped", },
+	{ .offset = LAN9303_BM_DRP_CNT_SRC_0, .name = "TxDropped", },
+};
+
 static void lan9303_get_strings(struct dsa_switch *ds, int port,
 				u32 stringset, uint8_t *data)
 {
-	unsigned int u;
+	unsigned int i, u;
 
 	if (stringset != ETH_SS_STATS)
 		return;
@@ -990,26 +998,44 @@ static void lan9303_get_strings(struct dsa_switch *ds, int port,
 		strncpy(data + u * ETH_GSTRING_LEN, lan9303_mib[u].name,
 			ETH_GSTRING_LEN);
 	}
+	for (i = 0; i < ARRAY_SIZE(lan9303_switch_mib); i++) {
+		strncpy(data + (u + i) * ETH_GSTRING_LEN,
+			lan9303_switch_mib[i].name, ETH_GSTRING_LEN);
+	}
 }
 
 static void lan9303_get_ethtool_stats(struct dsa_switch *ds, int port,
 				      uint64_t *data)
 {
 	struct lan9303 *chip = ds->priv;
-	unsigned int u;
+	unsigned int i, u;
 
 	for (u = 0; u < ARRAY_SIZE(lan9303_mib); u++) {
 		u32 reg;
 		int ret;
 
-		ret = lan9303_read_switch_port(
-			chip, port, lan9303_mib[u].offset, &reg);
-
+		/* Read Port-based MIB stats. */
+		ret = lan9303_read_switch_port(chip, port,
+					       lan9303_mib[u].offset,
+					       &reg);
 		if (ret)
 			dev_warn(chip->dev, "Reading status port %d reg %u failed\n",
 				 port, lan9303_mib[u].offset);
 		data[u] = reg;
 	}
+	for (i = 0; i < ARRAY_SIZE(lan9303_switch_mib); i++) {
+		u32 reg;
+		int ret;
+
+		/* Read Switch stats indexed by port. */
+		ret = lan9303_read_switch_reg(chip,
+					      (lan9303_switch_mib[i].offset +
+					       port), &reg);
+		if (ret)
+			dev_warn(chip->dev, "Reading status port %d reg %u failed\n",
+				 port, lan9303_switch_mib[i].offset);
+		data[i + u] = reg;
+	}
 }
 
 static int lan9303_get_sset_count(struct dsa_switch *ds, int port, int sset)
@@ -1017,7 +1043,7 @@ static int lan9303_get_sset_count(struct dsa_switch *ds, int port, int sset)
 	if (sset != ETH_SS_STATS)
 		return 0;
 
-	return ARRAY_SIZE(lan9303_mib);
+	return ARRAY_SIZE(lan9303_mib) + ARRAY_SIZE(lan9303_switch_mib);
 }
 
 static int lan9303_phy_read(struct dsa_switch *ds, int phy, int regnum)
-- 
2.17.1