[PATCH v1 2/2] realtek: consistently flood RMA frames

[Sander Vanheule]

The switches support different actions for incoming ethernet multicast
frames with Reserved Multicast Addresses (01-80-C2-00-00-{01-2F}). The
current code will set the 2-bit action field to FLOOD (0x3) for most
classes, but the highest bit is always unset for the relevant control
registers. This means the DROP (0x1) action being used for these
classes; whatever class the MSB happens to be in.

For RTL838x, this results in {20,23-2F} frames being dropped, instead of
flooding all ports. On other switch generations, {0F,1F,2F} frames are
dropped. This is inconsistent, and appears to be a mistake. Remove this
inconsistency by flooding all multicast frames with RMA addresses.

Signed-off-by: Sander Vanheule <sander at svanheule.net>
---
 .../drivers/net/ethernet/rtl838x_eth.c        | 70 +++++++++++--------
 1 file changed, 40 insertions(+), 30 deletions(-)

diff --git a/target/linux/realtek/files-5.10/drivers/net/ethernet/rtl838x_eth.c b/target/linux/realtek/files-5.10/drivers/net/ethernet/rtl838x_eth.c
index fcb6a6d10e6d..c4cbcfded843 100644
--- a/target/linux/realtek/files-5.10/drivers/net/ethernet/rtl838x_eth.c
+++ b/target/linux/realtek/files-5.10/drivers/net/ethernet/rtl838x_eth.c
@@ -1032,20 +1032,30 @@ static int rtl838x_eth_stop(struct net_device *ndev)
 
 static void rtl838x_eth_set_multicast_list(struct net_device *ndev)
 {
+	/*
+	 * Flood all classes of RMA addresses (01-80-C2-00-00-{01..2F})
+	 * CTRL_0_FULL = GENMASK(21, 0) = 0x3FFFFF
+	 */
 	if (!(ndev->flags & (IFF_PROMISC | IFF_ALLMULTI))) {
 		sw_w32(0x0, RTL838X_RMA_CTRL_0);
 		sw_w32(0x0, RTL838X_RMA_CTRL_1);
 	}
 	if (ndev->flags & IFF_ALLMULTI)
-		sw_w32(0x1fffff, RTL838X_RMA_CTRL_0);
+		sw_w32(GENMASK(21, 0), RTL838X_RMA_CTRL_0);
 	if (ndev->flags & IFF_PROMISC) {
-		sw_w32(0x1fffff, RTL838X_RMA_CTRL_0);
+		sw_w32(GENMASK(21, 0), RTL838X_RMA_CTRL_0);
 		sw_w32(0x7fff, RTL838X_RMA_CTRL_1);
 	}
 }
 
 static void rtl839x_eth_set_multicast_list(struct net_device *ndev)
 {
+	/*
+	 * Flood all classes of RMA addresses (01-80-C2-00-00-{01..2F})
+	 * CTRL_0_FULL = GENMASK(31, 2) = 0xFFFFFFFC
+	 * Lower two bits are reserved, corresponding to RMA 01-80-C2-00-00-00
+	 * CTRL_1_FULL = CTRL_2_FULL = GENMASK(31, 0)
+	 */
 	if (!(ndev->flags & (IFF_PROMISC | IFF_ALLMULTI))) {
 		sw_w32(0x0, RTL839X_RMA_CTRL_0);
 		sw_w32(0x0, RTL839X_RMA_CTRL_1);
@@ -1053,54 +1063,54 @@ static void rtl839x_eth_set_multicast_list(struct net_device *ndev)
 		sw_w32(0x0, RTL839X_RMA_CTRL_3);
 	}
 	if (ndev->flags & IFF_ALLMULTI) {
-		sw_w32(0x7fffffff, RTL839X_RMA_CTRL_0);
-		sw_w32(0x7fffffff, RTL839X_RMA_CTRL_1);
-		sw_w32(0x7fffffff, RTL839X_RMA_CTRL_2);
+		sw_w32(GENMASK(31, 2), RTL839X_RMA_CTRL_0);
+		sw_w32(GENMASK(31, 0), RTL839X_RMA_CTRL_1);
+		sw_w32(GENMASK(31, 0), RTL839X_RMA_CTRL_2);
 	}
 	if (ndev->flags & IFF_PROMISC) {
-		sw_w32(0x7fffffff, RTL839X_RMA_CTRL_0);
-		sw_w32(0x7fffffff, RTL839X_RMA_CTRL_1);
-		sw_w32(0x7fffffff, RTL839X_RMA_CTRL_2);
+		sw_w32(GENMASK(31, 2), RTL839X_RMA_CTRL_0);
+		sw_w32(GENMASK(31, 0), RTL839X_RMA_CTRL_1);
+		sw_w32(GENMASK(31, 0), RTL839X_RMA_CTRL_2);
 		sw_w32(0x3ff, RTL839X_RMA_CTRL_3);
 	}
 }
 
 static void rtl930x_eth_set_multicast_list(struct net_device *ndev)
 {
-	if (!(ndev->flags & (IFF_PROMISC | IFF_ALLMULTI))) {
+	/*
+	 * Flood all classes of RMA addresses (01-80-C2-00-00-{01..2F})
+	 * CTRL_0_FULL = GENMASK(31, 2) = 0xFFFFFFFC
+	 * Lower two bits are reserved, corresponding to RMA 01-80-C2-00-00-00
+	 * CTRL_1_FULL = CTRL_2_FULL = GENMASK(31, 0)
+	 */
+	if (ndev->flags & (IFF_ALLMULTI | IFF_PROMISC)) {
+		sw_w32(GENMASK(31, 2), RTL930X_RMA_CTRL_0);
+		sw_w32(GENMASK(31, 0), RTL930X_RMA_CTRL_1);
+		sw_w32(GENMASK(31, 0), RTL930X_RMA_CTRL_2);
+	} else {
 		sw_w32(0x0, RTL930X_RMA_CTRL_0);
 		sw_w32(0x0, RTL930X_RMA_CTRL_1);
 		sw_w32(0x0, RTL930X_RMA_CTRL_2);
 	}
-	if (ndev->flags & IFF_ALLMULTI) {
-		sw_w32(0x7fffffff, RTL930X_RMA_CTRL_0);
-		sw_w32(0x7fffffff, RTL930X_RMA_CTRL_1);
-		sw_w32(0x7fffffff, RTL930X_RMA_CTRL_2);
-	}
-	if (ndev->flags & IFF_PROMISC) {
-		sw_w32(0x7fffffff, RTL930X_RMA_CTRL_0);
-		sw_w32(0x7fffffff, RTL930X_RMA_CTRL_1);
-		sw_w32(0x7fffffff, RTL930X_RMA_CTRL_2);
-	}
 }
 
 static void rtl931x_eth_set_multicast_list(struct net_device *ndev)
 {
-	if (!(ndev->flags & (IFF_PROMISC | IFF_ALLMULTI))) {
+	/*
+	 * Flood all classes of RMA addresses (01-80-C2-00-00-{01..2F})
+	 * CTRL_0_FULL = GENMASK(31, 2) = 0xFFFFFFFC
+	 * Lower two bits are reserved, corresponding to RMA 01-80-C2-00-00-00.
+	 * CTRL_1_FULL = CTRL_2_FULL = GENMASK(31, 0)
+	 */
+	if (ndev->flags & (IFF_ALLMULTI | IFF_PROMISC)) {
+		sw_w32(GENMASK(31, 2), RTL931X_RMA_CTRL_0);
+		sw_w32(GENMASK(31, 0), RTL931X_RMA_CTRL_1);
+		sw_w32(GENMASK(31, 0), RTL931X_RMA_CTRL_2);
+	} else {
 		sw_w32(0x0, RTL931X_RMA_CTRL_0);
 		sw_w32(0x0, RTL931X_RMA_CTRL_1);
 		sw_w32(0x0, RTL931X_RMA_CTRL_2);
 	}
-	if (ndev->flags & IFF_ALLMULTI) {
-		sw_w32(0x7fffffff, RTL931X_RMA_CTRL_0);
-		sw_w32(0x7fffffff, RTL931X_RMA_CTRL_1);
-		sw_w32(0x7fffffff, RTL931X_RMA_CTRL_2);
-	}
-	if (ndev->flags & IFF_PROMISC) {
-		sw_w32(0x7fffffff, RTL931X_RMA_CTRL_0);
-		sw_w32(0x7fffffff, RTL931X_RMA_CTRL_1);
-		sw_w32(0x7fffffff, RTL931X_RMA_CTRL_2);
-	}
 }
 
 static void rtl838x_eth_tx_timeout(struct net_device *ndev, unsigned int txqueue)
-- 
2.37.3