diff mbox series

[net-next,v1,4/7] net: dsa: microchip: ksz8_r_sta_mac_table(): Avoid using error code for empty entries

Message ID 20230404101842.1382986-5-o.rempel@pengutronix.de
State New
Headers
Series net: dsa: microchip: ksz8: Enhance static MAC table operations and error handling |

Commit Message

Oleksij Rempel April 4, 2023, 10:18 a.m. UTC 
  Prepare for the next patch by ensuring that ksz8_r_sta_mac_table() does
not use error codes for empty entries. This change will enable better
handling of read/write errors in the upcoming patch.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
 drivers/net/dsa/microchip/ksz8795.c | 87 +++++++++++++++++------------
 1 file changed, 50 insertions(+), 37 deletions(-)

Comments

Vladimir Oltean April 4, 2023, 11:58 a.m. UTC | #1 
On Tue, Apr 04, 2023 at 12:18:39PM +0200, Oleksij Rempel wrote:
> Prepare for the next patch by ensuring that ksz8_r_sta_mac_table() does
> not use error codes for empty entries. This change will enable better
> handling of read/write errors in the upcoming patch.
> 
> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
> ---

Reviewed-by: Vladimir Oltean <olteanv@gmail.com>

FWIW, it looks like for port_fdb_add(), you could skip the search in the
static MAC table, as long as you just keep a reference to the last
populated index, because the bridge won't allow, to my knowledge, adding
the same MAC address twice (this has changed when we stopped allowing
bridge bypass operations in commit b117e1e8a86d ("net: dsa: delete
dsa_legacy_fdb_add and dsa_legacy_fdb_del")), and so, having space would
mean that the last populated index is < dev->info->num_statics - 1.

This guarantee and optimization possibility is different from
port_mdb_add(), because there, you might be asked to modify an existing
entry, and so, you still need the search to find it. But still, you
could limit the search for the remaining 3 operations - port_fdb_del(),
port_mdb_add(), port_mdb_del() - just from 0 to that last populated
entry, not to dev->info->num_statics, which should still accelerate the
operations a bit.
diff mbox series

Patch

diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
index fc079d6eee80..4dcf68a7f6c0 100644
--- a/drivers/net/dsa/microchip/ksz8795.c
+++ b/drivers/net/dsa/microchip/ksz8795.c
@@ -458,7 +458,7 @@  int ksz8_r_dyn_mac_table(struct ksz_device *dev, u16 addr, u8 *mac_addr,
 }
 
 static int ksz8_r_sta_mac_table(struct ksz_device *dev, u16 addr,
-				struct alu_struct *alu)
+				struct alu_struct *alu, bool *valid)
 {
 	u32 data_hi, data_lo;
 	const u8 *shifts;
@@ -471,28 +471,32 @@  static int ksz8_r_sta_mac_table(struct ksz_device *dev, u16 addr,
 	ksz8_r_table(dev, TABLE_STATIC_MAC, addr, &data);
 	data_hi = data >> 32;
 	data_lo = (u32)data;
-	if (data_hi & (masks[STATIC_MAC_TABLE_VALID] |
-			masks[STATIC_MAC_TABLE_OVERRIDE])) {
-		alu->mac[5] = (u8)data_lo;
-		alu->mac[4] = (u8)(data_lo >> 8);
-		alu->mac[3] = (u8)(data_lo >> 16);
-		alu->mac[2] = (u8)(data_lo >> 24);
-		alu->mac[1] = (u8)data_hi;
-		alu->mac[0] = (u8)(data_hi >> 8);
-		alu->port_forward =
-			(data_hi & masks[STATIC_MAC_TABLE_FWD_PORTS]) >>
-				shifts[STATIC_MAC_FWD_PORTS];
-		alu->is_override =
-			(data_hi & masks[STATIC_MAC_TABLE_OVERRIDE]) ? 1 : 0;
-		data_hi >>= 1;
-		alu->is_static = true;
-		alu->is_use_fid =
-			(data_hi & masks[STATIC_MAC_TABLE_USE_FID]) ? 1 : 0;
-		alu->fid = (data_hi & masks[STATIC_MAC_TABLE_FID]) >>
-				shifts[STATIC_MAC_FID];
+
+	if (!(data_hi & (masks[STATIC_MAC_TABLE_VALID] |
+			 masks[STATIC_MAC_TABLE_OVERRIDE]))) {
+		*valid = false;
 		return 0;
 	}
-	return -ENXIO;
+
+	alu->mac[5] = (u8)data_lo;
+	alu->mac[4] = (u8)(data_lo >> 8);
+	alu->mac[3] = (u8)(data_lo >> 16);
+	alu->mac[2] = (u8)(data_lo >> 24);
+	alu->mac[1] = (u8)data_hi;
+	alu->mac[0] = (u8)(data_hi >> 8);
+	alu->port_forward =
+		(data_hi & masks[STATIC_MAC_TABLE_FWD_PORTS]) >>
+			shifts[STATIC_MAC_FWD_PORTS];
+	alu->is_override = (data_hi & masks[STATIC_MAC_TABLE_OVERRIDE]) ? 1 : 0;
+	data_hi >>= 1;
+	alu->is_static = true;
+	alu->is_use_fid = (data_hi & masks[STATIC_MAC_TABLE_USE_FID]) ? 1 : 0;
+	alu->fid = (data_hi & masks[STATIC_MAC_TABLE_FID]) >>
+		shifts[STATIC_MAC_FID];
+
+	*valid = true;
+
+	return 0;
 }
 
 void ksz8_w_sta_mac_table(struct ksz_device *dev, u16 addr,
@@ -993,20 +997,25 @@  static int ksz8_add_sta_mac(struct ksz_device *dev, int port,
 			    const unsigned char *addr, u16 vid)
 {
 	struct alu_struct alu;
-	int index;
+	int index, ret;
 	int empty = 0;
 
 	alu.port_forward = 0;
 	for (index = 0; index < dev->info->num_statics; index++) {
-		if (!ksz8_r_sta_mac_table(dev, index, &alu)) {
-			/* Found one already in static MAC table. */
-			if (!memcmp(alu.mac, addr, ETH_ALEN) &&
-			    alu.fid == vid)
-				break;
-		/* Remember the first empty entry. */
-		} else if (!empty) {
-			empty = index + 1;
+		bool valid;
+
+		ret = ksz8_r_sta_mac_table(dev, index, &alu, &valid);
+		if (ret)
+			return ret;
+		if (!valid) {
+			/* Remember the first empty entry. */
+			if (!empty)
+				empty = index + 1;
+			continue;
 		}
+
+		if (!memcmp(alu.mac, addr, ETH_ALEN) && alu.fid == vid)
+			break;
 	}
 
 	/* no available entry */
@@ -1036,15 +1045,19 @@  static int ksz8_del_sta_mac(struct ksz_device *dev, int port,
 			    const unsigned char *addr, u16 vid)
 {
 	struct alu_struct alu;
-	int index;
+	int index, ret;
 
 	for (index = 0; index < dev->info->num_statics; index++) {
-		if (!ksz8_r_sta_mac_table(dev, index, &alu)) {
-			/* Found one already in static MAC table. */
-			if (!memcmp(alu.mac, addr, ETH_ALEN) &&
-			    alu.fid == vid)
-				break;
-		}
+		bool valid;
+
+		ret = ksz8_r_sta_mac_table(dev, index, &alu, &valid);
+		if (ret)
+			return ret;
+		if (!valid)
+			continue;
+
+		if (!memcmp(alu.mac, addr, ETH_ALEN) && alu.fid == vid)
+			break;
 	}
 
 	/* no available entry */