amd-xgbe: Add support for VLAN filtering

This patch adds support for (imperfect) filtering of
VLAN tag ids using a 16-bit filter hash table.  When
VLANs are added, a 4-bit hash is calculated with the
result indicating the bit in the hash table to set.
This table is used by the hardware to drop packets with
a VLAN id that does not hash to a set bit in the table.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/amd/Kconfig

@@ -182,6 +182,7 @@ config AMD_XGBE
 	depends on OF_NET
 	select PHYLIB
 	select AMD_XGBE_PHY
+	select BITREVERSE
 	---help---
 	  This driver supports the AMD 10GbE Ethernet device found on an
 	  AMD SoC.

drivers/net/ethernet/amd/xgbe/xgbe-common.h

@@ -393,6 +393,8 @@
 #define MAC_PFR_PM_WIDTH		1
 #define MAC_PFR_PR_INDEX		0
 #define MAC_PFR_PR_WIDTH		1
+#define MAC_PFR_VTFE_INDEX		16
+#define MAC_PFR_VTFE_WIDTH		1
 #define MAC_PMTCSR_MGKPKTEN_INDEX	1
 #define MAC_PMTCSR_MGKPKTEN_WIDTH	1
 #define MAC_PMTCSR_PWRDWN_INDEX		0
@@ -427,6 +429,8 @@
 #define MAC_TCR_SS_WIDTH		2
 #define MAC_TCR_TE_INDEX		0
 #define MAC_TCR_TE_WIDTH		1
+#define MAC_VLANHTR_VLHT_INDEX		0
+#define MAC_VLANHTR_VLHT_WIDTH		16
 #define MAC_VLANIR_VLTI_INDEX		20
 #define MAC_VLANIR_VLTI_WIDTH		1
 #define MAC_VLANIR_CSVL_INDEX		19
@@ -437,10 +441,18 @@
 #define MAC_VLANTR_ERSVLM_WIDTH		1
 #define MAC_VLANTR_ESVL_INDEX		18
 #define MAC_VLANTR_ESVL_WIDTH		1
+#define MAC_VLANTR_ETV_INDEX		16
+#define MAC_VLANTR_ETV_WIDTH		1
 #define MAC_VLANTR_EVLS_INDEX		21
 #define MAC_VLANTR_EVLS_WIDTH		2
 #define MAC_VLANTR_EVLRXS_INDEX		24
 #define MAC_VLANTR_EVLRXS_WIDTH		1
+#define MAC_VLANTR_VL_INDEX		0
+#define MAC_VLANTR_VL_WIDTH		16
+#define MAC_VLANTR_VTHM_INDEX		25
+#define MAC_VLANTR_VTHM_WIDTH		1
+#define MAC_VLANTR_VTIM_INDEX		17
+#define MAC_VLANTR_VTIM_WIDTH		1
 #define MAC_VR_DEVID_INDEX		8
 #define MAC_VR_DEVID_WIDTH		8
 #define MAC_VR_SNPSVER_INDEX		0

drivers/net/ethernet/amd/xgbe/xgbe-dev.c

@@ -116,6 +116,7 @@
 
 #include <linux/phy.h>
 #include <linux/clk.h>
+#include <linux/bitrev.h>
 
 #include "xgbe.h"
 #include "xgbe-common.h"
@@ -738,6 +739,89 @@ static int xgbe_disable_rx_vlan_stripping(struct xgbe_prv_data *pdata)
 	return 0;
 }
 
+static int xgbe_enable_rx_vlan_filtering(struct xgbe_prv_data *pdata)
+{
+	/* Enable VLAN filtering */
+	XGMAC_IOWRITE_BITS(pdata, MAC_PFR, VTFE, 1);
+
+	/* Enable VLAN Hash Table filtering */
+	XGMAC_IOWRITE_BITS(pdata, MAC_VLANTR, VTHM, 1);
+
+	/* Disable VLAN tag inverse matching */
+	XGMAC_IOWRITE_BITS(pdata, MAC_VLANTR, VTIM, 0);
+
+	/* Only filter on the lower 12-bits of the VLAN tag */
+	XGMAC_IOWRITE_BITS(pdata, MAC_VLANTR, ETV, 1);
+
+	/* In order for the VLAN Hash Table filtering to be effective,
+	 * the VLAN tag identifier in the VLAN Tag Register must not
+	 * be zero.  Set the VLAN tag identifier to "1" to enable the
+	 * VLAN Hash Table filtering.  This implies that a VLAN tag of
+	 * 1 will always pass filtering.
+	 */
+	XGMAC_IOWRITE_BITS(pdata, MAC_VLANTR, VL, 1);
+
+	return 0;
+}
+
+static int xgbe_disable_rx_vlan_filtering(struct xgbe_prv_data *pdata)
+{
+	/* Disable VLAN filtering */
+	XGMAC_IOWRITE_BITS(pdata, MAC_PFR, VTFE, 0);
+
+	return 0;
+}
+
+#ifndef CRCPOLY_LE
+#define CRCPOLY_LE 0xedb88320
+#endif
+static u32 xgbe_vid_crc32_le(__le16 vid_le)
+{
+	u32 poly = CRCPOLY_LE;
+	u32 crc = ~0;
+	u32 temp = 0;
+	unsigned char *data = (unsigned char *)&vid_le;
+	unsigned char data_byte = 0;
+	int i, bits;
+
+	bits = get_bitmask_order(VLAN_VID_MASK);
+	for (i = 0; i < bits; i++) {
+		if ((i % 8) == 0)
+			data_byte = data[i / 8];
+
+		temp = ((crc & 1) ^ data_byte) & 1;
+		crc >>= 1;
+		data_byte >>= 1;
+
+		if (temp)
+			crc ^= poly;
+	}
+
+	return crc;
+}
+
+static int xgbe_update_vlan_hash_table(struct xgbe_prv_data *pdata)
+{
+	u32 crc;
+	u16 vid;
+	__le16 vid_le;
+	u16 vlan_hash_table = 0;
+
+	/* Generate the VLAN Hash Table value */
+	for_each_set_bit(vid, pdata->active_vlans, VLAN_N_VID) {
+		/* Get the CRC32 value of the VLAN ID */
+		vid_le = cpu_to_le16(vid);
+		crc = bitrev32(~xgbe_vid_crc32_le(vid_le)) >> 28;
+
+		vlan_hash_table |= (1 << crc);
+	}
+
+	/* Set the VLAN Hash Table filtering register */
+	XGMAC_IOWRITE_BITS(pdata, MAC_VLANHTR, VLHT, vlan_hash_table);
+
+	return 0;
+}
+
 static void xgbe_tx_desc_reset(struct xgbe_ring_data *rdata)
 {
 	struct xgbe_ring_desc *rdesc = rdata->rdesc;
@@ -1547,6 +1631,14 @@ static void xgbe_config_vlan_support(struct xgbe_prv_data *pdata)
 	XGMAC_IOWRITE_BITS(pdata, MAC_VLANIR, CSVL, 0);
 	XGMAC_IOWRITE_BITS(pdata, MAC_VLANIR, VLTI, 1);
 
+	/* Set the current VLAN Hash Table register value */
+	xgbe_update_vlan_hash_table(pdata);
+
+	if (pdata->netdev->features & NETIF_F_HW_VLAN_CTAG_FILTER)
+		xgbe_enable_rx_vlan_filtering(pdata);
+	else
+		xgbe_disable_rx_vlan_filtering(pdata);
+
 	if (pdata->netdev->features & NETIF_F_HW_VLAN_CTAG_RX)
 		xgbe_enable_rx_vlan_stripping(pdata);
 	else
@@ -2118,6 +2210,9 @@ void xgbe_init_function_ptrs_dev(struct xgbe_hw_if *hw_if)
 
 	hw_if->enable_rx_vlan_stripping = xgbe_enable_rx_vlan_stripping;
 	hw_if->disable_rx_vlan_stripping = xgbe_disable_rx_vlan_stripping;
+	hw_if->enable_rx_vlan_filtering = xgbe_enable_rx_vlan_filtering;
+	hw_if->disable_rx_vlan_filtering = xgbe_disable_rx_vlan_filtering;
+	hw_if->update_vlan_hash_table = xgbe_update_vlan_hash_table;
 
 	hw_if->read_mmd_regs = xgbe_read_mmd_regs;
 	hw_if->write_mmd_regs = xgbe_write_mmd_regs;

drivers/net/ethernet/amd/xgbe/xgbe-drv.c

@@ -1000,6 +1000,38 @@ static struct rtnl_link_stats64 *xgbe_get_stats64(struct net_device *netdev,
 	return s;
 }
 
+static int xgbe_vlan_rx_add_vid(struct net_device *netdev, __be16 proto,
+				u16 vid)
+{
+	struct xgbe_prv_data *pdata = netdev_priv(netdev);
+	struct xgbe_hw_if *hw_if = &pdata->hw_if;
+
+	DBGPR("-->%s\n", __func__);
+
+	set_bit(vid, pdata->active_vlans);
+	hw_if->update_vlan_hash_table(pdata);
+
+	DBGPR("<--%s\n", __func__);
+
+	return 0;
+}
+
+static int xgbe_vlan_rx_kill_vid(struct net_device *netdev, __be16 proto,
+				 u16 vid)
+{
+	struct xgbe_prv_data *pdata = netdev_priv(netdev);
+	struct xgbe_hw_if *hw_if = &pdata->hw_if;
+
+	DBGPR("-->%s\n", __func__);
+
+	clear_bit(vid, pdata->active_vlans);
+	hw_if->update_vlan_hash_table(pdata);
+
+	DBGPR("<--%s\n", __func__);
+
+	return 0;
+}
+
 #ifdef CONFIG_NET_POLL_CONTROLLER
 static void xgbe_poll_controller(struct net_device *netdev)
 {
@@ -1022,26 +1054,26 @@ static int xgbe_set_features(struct net_device *netdev,
 {
 	struct xgbe_prv_data *pdata = netdev_priv(netdev);
 	struct xgbe_hw_if *hw_if = &pdata->hw_if;
-	unsigned int rxcsum_enabled, rxvlan_enabled;
+	unsigned int rxcsum, rxvlan, rxvlan_filter;
 
-	rxcsum_enabled = !!(pdata->netdev_features & NETIF_F_RXCSUM);
-	rxvlan_enabled = !!(pdata->netdev_features & NETIF_F_HW_VLAN_CTAG_RX);
+	rxcsum = pdata->netdev_features & NETIF_F_RXCSUM;
+	rxvlan = pdata->netdev_features & NETIF_F_HW_VLAN_CTAG_RX;
+	rxvlan_filter = pdata->netdev_features & NETIF_F_HW_VLAN_CTAG_FILTER;
 
-	if ((features & NETIF_F_RXCSUM) && !rxcsum_enabled) {
+	if ((features & NETIF_F_RXCSUM) && !rxcsum)
 		hw_if->enable_rx_csum(pdata);
-		netdev_alert(netdev, "state change - rxcsum enabled\n");
-	} else if (!(features & NETIF_F_RXCSUM) && rxcsum_enabled) {
+	else if (!(features & NETIF_F_RXCSUM) && rxcsum)
 		hw_if->disable_rx_csum(pdata);
-		netdev_alert(netdev, "state change - rxcsum disabled\n");
-	}
 
-	if ((features & NETIF_F_HW_VLAN_CTAG_RX) && !rxvlan_enabled) {
+	if ((features & NETIF_F_HW_VLAN_CTAG_RX) && !rxvlan)
 		hw_if->enable_rx_vlan_stripping(pdata);
-		netdev_alert(netdev, "state change - rxvlan enabled\n");
-	} else if (!(features & NETIF_F_HW_VLAN_CTAG_RX) && rxvlan_enabled) {
+	else if (!(features & NETIF_F_HW_VLAN_CTAG_RX) && rxvlan)
 		hw_if->disable_rx_vlan_stripping(pdata);
-		netdev_alert(netdev, "state change - rxvlan disabled\n");
-	}
+
+	if ((features & NETIF_F_HW_VLAN_CTAG_FILTER) && !rxvlan_filter)
+		hw_if->enable_rx_vlan_filtering(pdata);
+	else if (!(features & NETIF_F_HW_VLAN_CTAG_FILTER) && rxvlan_filter)
+		hw_if->disable_rx_vlan_filtering(pdata);
 
 	pdata->netdev_features = features;
 
@@ -1059,6 +1091,8 @@ static const struct net_device_ops xgbe_netdev_ops = {
 	.ndo_validate_addr	= eth_validate_addr,
 	.ndo_change_mtu		= xgbe_change_mtu,
 	.ndo_get_stats64	= xgbe_get_stats64,
+	.ndo_vlan_rx_add_vid	= xgbe_vlan_rx_add_vid,
+	.ndo_vlan_rx_kill_vid	= xgbe_vlan_rx_kill_vid,
 #ifdef CONFIG_NET_POLL_CONTROLLER
 	.ndo_poll_controller	= xgbe_poll_controller,
 #endif

drivers/net/ethernet/amd/xgbe/xgbe-main.c

@@ -385,7 +385,8 @@ static int xgbe_probe(struct platform_device *pdev)
 			      NETIF_F_TSO6 |
 			      NETIF_F_GRO |
 			      NETIF_F_HW_VLAN_CTAG_RX |
-			      NETIF_F_HW_VLAN_CTAG_TX;
+			      NETIF_F_HW_VLAN_CTAG_TX |
+			      NETIF_F_HW_VLAN_CTAG_FILTER;
 
 	netdev->vlan_features |= NETIF_F_SG |
 				 NETIF_F_IP_CSUM |

drivers/net/ethernet/amd/xgbe/xgbe.h

@@ -121,6 +121,8 @@
 #include <linux/netdevice.h>
 #include <linux/workqueue.h>
 #include <linux/phy.h>
+#include <linux/if_vlan.h>
+#include <linux/bitops.h>
 
 
 #define XGBE_DRV_NAME		"amd-xgbe"
@@ -393,6 +395,9 @@ struct xgbe_hw_if {
 
 	int (*enable_rx_vlan_stripping)(struct xgbe_prv_data *);
 	int (*disable_rx_vlan_stripping)(struct xgbe_prv_data *);
+	int (*enable_rx_vlan_filtering)(struct xgbe_prv_data *);
+	int (*disable_rx_vlan_filtering)(struct xgbe_prv_data *);
+	int (*update_vlan_hash_table)(struct xgbe_prv_data *);
 
 	int (*read_mmd_regs)(struct xgbe_prv_data *, int, int);
 	void (*write_mmd_regs)(struct xgbe_prv_data *, int, int, int);
@@ -588,6 +593,9 @@ struct xgbe_prv_data {
 	struct napi_struct napi;
 	struct xgbe_mmc_stats mmc_stats;
 
+	/* Filtering support */
+	unsigned long active_vlans[BITS_TO_LONGS(VLAN_N_VID)];
+
 	/* System clock value used for Rx watchdog */
 	struct clk *sysclock;