net: dsa: microchip: ksz8: Refactor ksz8_fdb_dump()

Refactor ksz8_fdb_dump() to address potential issues:
- Limit the number of iterations to avoid endless loops.
- Handle error codes returned by ksz8_r_dyn_mac_table(), with
  an exception for -ENXIO when no more dynamic entries are detected.

Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Acked-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Link: https://lore.kernel.org/r/20240403125039.3414824-4-o.rempel@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
index e407111db663779f50e03e67816a678ed095d405..c93eb351ab3d555ee51ba6899c2fda151e51c741 100644 (file)
--- a/drivers/net/dsa/microchip/ksz8795.c
+++ b/drivers/net/dsa/microchip/ksz8795.c
@@ -1191,27 +1191,30 @@ void ksz8_flush_dyn_mac_table(struct ksz_device *dev, int port)
 int ksz8_fdb_dump(struct ksz_device *dev, int port,
                  dsa_fdb_dump_cb_t *cb, void *data)
 {
-       int ret = 0;
-       u16 i = 0;
-       u16 entries = 0;
-       u8 fid;
-       u8 src_port;
        u8 mac[ETH_ALEN];
+       u8 src_port, fid;
+       u16 entries = 0;
+       int ret, i;
 
-       do {
+       for (i = 0; i < KSZ8_DYN_MAC_ENTRIES; i++) {
                ret = ksz8_r_dyn_mac_table(dev, i, mac, &fid, &src_port,
                                           &entries);
-               if (!ret && port == src_port) {
+               if (ret == -ENXIO)
+                       return 0;
+               if (ret)
+                       return ret;
+
+               if (i >= entries)
+                       return 0;
+
+               if (port == src_port) {
                        ret = cb(mac, fid, false, data);
                        if (ret)
-                               break;
+                               return ret;
                }
-               i++;
-       } while (i < entries);
-       if (i >= entries)
-               ret = 0;
+       }
 
-       return ret;
+       return 0;
 }
 
 static int ksz8_add_sta_mac(struct ksz_device *dev, int port,

diff --git a/drivers/net/dsa/microchip/ksz8795_reg.h b/drivers/net/dsa/microchip/ksz8795_reg.h
index 7c9341ef73b030c9e285221fc489e5218dc88d0d..0d13a6e29b0e6d508c270fd0bb6093a09e74c990 100644 (file)
--- a/drivers/net/dsa/microchip/ksz8795_reg.h
+++ b/drivers/net/dsa/microchip/ksz8795_reg.h
@@ -794,5 +794,6 @@
 #define TAIL_TAG_LOOKUP                        BIT(7)
 
 #define FID_ENTRIES                    128
+#define KSZ8_DYN_MAC_ENTRIES           1024
 
 #endif