igc: Add set_rx_mode support

Add multicast addresses list to the MTA table.
Implement basic Rx mode support.
Add option for IPv6 address settings.

Signed-off-by: Sasha Neftin <[email protected]>
Tested-by: Aaron Brown <[email protected]>
Signed-off-by: Jeff Kirsher <[email protected]>

Author: Sasha Neftin

drivers/net/ethernet/intel/igc/igc_defines.h

@@ -402,4 +402,7 @@
 #define IGC_ADVTXD_TUCMD_L4T_TCP	0x00000800  /* L4 Packet Type of TCP */
 #define IGC_ADVTXD_TUCMD_L4T_SCTP	0x00001000 /* L4 packet TYPE of SCTP */
 
+/* Maximum size of the MTA register table in all supported adapters */
+#define MAX_MTA_REG			128
+
 #endif /* _IGC_DEFINES_H_ */

drivers/net/ethernet/intel/igc/igc_hw.h

@@ -91,6 +91,7 @@ struct igc_mac_info {
 	u16 mta_reg_count;
 	u16 uta_reg_count;
 
+	u32 mta_shadow[MAX_MTA_REG];
 	u16 rar_entry_count;
 
 	u8 forced_speed_duplex;

drivers/net/ethernet/intel/igc/igc_mac.c

@@ -784,3 +784,107 @@ bool igc_enable_mng_pass_thru(struct igc_hw *hw)
 out:
 	return ret_val;
 }
+
+/**
+ *  igc_hash_mc_addr - Generate a multicast hash value
+ *  @hw: pointer to the HW structure
+ *  @mc_addr: pointer to a multicast address
+ *
+ *  Generates a multicast address hash value which is used to determine
+ *  the multicast filter table array address and new table value.  See
+ *  igc_mta_set()
+ **/
+static u32 igc_hash_mc_addr(struct igc_hw *hw, u8 *mc_addr)
+{
+	u32 hash_value, hash_mask;
+	u8 bit_shift = 0;
+
+	/* Register count multiplied by bits per register */
+	hash_mask = (hw->mac.mta_reg_count * 32) - 1;
+
+	/* For a mc_filter_type of 0, bit_shift is the number of left-shifts
+	 * where 0xFF would still fall within the hash mask.
+	 */
+	while (hash_mask >> bit_shift != 0xFF)
+		bit_shift++;
+
+	/* The portion of the address that is used for the hash table
+	 * is determined by the mc_filter_type setting.
+	 * The algorithm is such that there is a total of 8 bits of shifting.
+	 * The bit_shift for a mc_filter_type of 0 represents the number of
+	 * left-shifts where the MSB of mc_addr[5] would still fall within
+	 * the hash_mask.  Case 0 does this exactly.  Since there are a total
+	 * of 8 bits of shifting, then mc_addr[4] will shift right the
+	 * remaining number of bits. Thus 8 - bit_shift.  The rest of the
+	 * cases are a variation of this algorithm...essentially raising the
+	 * number of bits to shift mc_addr[5] left, while still keeping the
+	 * 8-bit shifting total.
+	 *
+	 * For example, given the following Destination MAC Address and an
+	 * MTA register count of 128 (thus a 4096-bit vector and 0xFFF mask),
+	 * we can see that the bit_shift for case 0 is 4.  These are the hash
+	 * values resulting from each mc_filter_type...
+	 * [0] [1] [2] [3] [4] [5]
+	 * 01  AA  00  12  34  56
+	 * LSB                 MSB
+	 *
+	 * case 0: hash_value = ((0x34 >> 4) | (0x56 << 4)) & 0xFFF = 0x563
+	 * case 1: hash_value = ((0x34 >> 3) | (0x56 << 5)) & 0xFFF = 0xAC6
+	 * case 2: hash_value = ((0x34 >> 2) | (0x56 << 6)) & 0xFFF = 0x163
+	 * case 3: hash_value = ((0x34 >> 0) | (0x56 << 8)) & 0xFFF = 0x634
+	 */
+	switch (hw->mac.mc_filter_type) {
+	default:
+	case 0:
+		break;
+	case 1:
+		bit_shift += 1;
+		break;
+	case 2:
+		bit_shift += 2;
+		break;
+	case 3:
+		bit_shift += 4;
+		break;
+	}
+
+	hash_value = hash_mask & (((mc_addr[4] >> (8 - bit_shift)) |
+				  (((u16)mc_addr[5]) << bit_shift)));
+
+	return hash_value;
+}
+
+/**
+ *  igc_update_mc_addr_list - Update Multicast addresses
+ *  @hw: pointer to the HW structure
+ *  @mc_addr_list: array of multicast addresses to program
+ *  @mc_addr_count: number of multicast addresses to program
+ *
+ *  Updates entire Multicast Table Array.
+ *  The caller must have a packed mc_addr_list of multicast addresses.
+ **/
+void igc_update_mc_addr_list(struct igc_hw *hw,
+			     u8 *mc_addr_list, u32 mc_addr_count)
+{
+	u32 hash_value, hash_bit, hash_reg;
+	int i;
+
+	/* clear mta_shadow */
+	memset(&hw->mac.mta_shadow, 0, sizeof(hw->mac.mta_shadow));
+
+	/* update mta_shadow from mc_addr_list */
+	for (i = 0; (u32)i < mc_addr_count; i++) {
+		hash_value = igc_hash_mc_addr(hw, mc_addr_list);
+
+		hash_reg = (hash_value >> 5) & (hw->mac.mta_reg_count - 1);
+		hash_bit = hash_value & 0x1F;
+
+		hw->mac.mta_shadow[hash_reg] |= BIT(hash_bit);
+		mc_addr_list += ETH_ALEN;
+	}
+
+	/* replace the entire MTA table */
+	for (i = hw->mac.mta_reg_count - 1; i >= 0; i--)
+		array_wr32(IGC_MTA, i, hw->mac.mta_shadow[i]);
+	wrfl();
+}

drivers/net/ethernet/intel/igc/igc_mac.h

@@ -29,6 +29,8 @@ s32 igc_get_speed_and_duplex_copper(struct igc_hw *hw, u16 *speed,
 				    u16 *duplex);
 
 bool igc_enable_mng_pass_thru(struct igc_hw *hw);
+void igc_update_mc_addr_list(struct igc_hw *hw,
+			     u8 *mc_addr_list, u32 mc_addr_count);
 
 enum igc_mng_mode {
 	igc_mng_mode_none = 0,

drivers/net/ethernet/intel/igc/igc_main.c

@@ -795,6 +795,44 @@ static int igc_set_mac(struct net_device *netdev, void *p)
 	return 0;
 }
 
+/**
+ *  igc_write_mc_addr_list - write multicast addresses to MTA
+ *  @netdev: network interface device structure
+ *
+ *  Writes multicast address list to the MTA hash table.
+ *  Returns: -ENOMEM on failure
+ *           0 on no addresses written
+ *           X on writing X addresses to MTA
+ **/
+static int igc_write_mc_addr_list(struct net_device *netdev)
+{
+	struct igc_adapter *adapter = netdev_priv(netdev);
+	struct igc_hw *hw = &adapter->hw;
+	struct netdev_hw_addr *ha;
+	u8  *mta_list;
+	int i;
+
+	if (netdev_mc_empty(netdev)) {
+		/* nothing to program, so clear mc list */
+		igc_update_mc_addr_list(hw, NULL, 0);
+		return 0;
+	}
+
+	mta_list = kcalloc(netdev_mc_count(netdev), 6, GFP_ATOMIC);
+	if (!mta_list)
+		return -ENOMEM;
+
+	/* The shared function expects a packed array of only addresses. */
+	i = 0;
+	netdev_for_each_mc_addr(ha, netdev)
+		memcpy(mta_list + (i++ * ETH_ALEN), ha->addr, ETH_ALEN);
+
+	igc_update_mc_addr_list(hw, mta_list, i);
+	kfree(mta_list);
+
+	return netdev_mc_count(netdev);
+}
+
 static void igc_tx_ctxtdesc(struct igc_ring *tx_ring,
 			    struct igc_tx_buffer *first,
 			    u32 vlan_macip_lens, u32 type_tucmd,
@@ -2518,6 +2556,110 @@ int igc_del_mac_steering_filter(struct igc_adapter *adapter,
 					IGC_MAC_STATE_QUEUE_STEERING | flags);
 }
 
+/* Add a MAC filter for 'addr' directing matching traffic to 'queue',
+ * 'flags' is used to indicate what kind of match is made, match is by
+ * default for the destination address, if matching by source address
+ * is desired the flag IGC_MAC_STATE_SRC_ADDR can be used.
+ */
+static int igc_add_mac_filter(struct igc_adapter *adapter,
+			      const u8 *addr, const u8 queue)
+{
+	struct igc_hw *hw = &adapter->hw;
+	int rar_entries = hw->mac.rar_entry_count;
+	int i;
+
+	if (is_zero_ether_addr(addr))
+		return -EINVAL;
+
+	/* Search for the first empty entry in the MAC table.
+	 * Do not touch entries at the end of the table reserved for the VF MAC
+	 * addresses.
+	 */
+	for (i = 0; i < rar_entries; i++) {
+		if (!igc_mac_entry_can_be_used(&adapter->mac_table[i],
+					       addr, 0))
+			continue;
+
+		ether_addr_copy(adapter->mac_table[i].addr, addr);
+		adapter->mac_table[i].queue = queue;
+		adapter->mac_table[i].state |= IGC_MAC_STATE_IN_USE;
+
+		igc_rar_set_index(adapter, i);
+		return i;
+	}
+
+	return -ENOSPC;
+}
+
+/* Remove a MAC filter for 'addr' directing matching traffic to
+ * 'queue', 'flags' is used to indicate what kind of match need to be
+ * removed, match is by default for the destination address, if
+ * matching by source address is to be removed the flag
+ * IGC_MAC_STATE_SRC_ADDR can be used.
+ */
+static int igc_del_mac_filter(struct igc_adapter *adapter,
+			      const u8 *addr, const u8 queue)
+{
+	struct igc_hw *hw = &adapter->hw;
+	int rar_entries = hw->mac.rar_entry_count;
+	int i;
+
+	if (is_zero_ether_addr(addr))
+		return -EINVAL;
+
+	/* Search for matching entry in the MAC table based on given address
+	 * and queue. Do not touch entries at the end of the table reserved
+	 * for the VF MAC addresses.
+	 */
+	for (i = 0; i < rar_entries; i++) {
+		if (!(adapter->mac_table[i].state & IGC_MAC_STATE_IN_USE))
+			continue;
+		if (adapter->mac_table[i].state != 0)
+			continue;
+		if (adapter->mac_table[i].queue != queue)
+			continue;
+		if (!ether_addr_equal(adapter->mac_table[i].addr, addr))
+			continue;
+
+		/* When a filter for the default address is "deleted",
+		 * we return it to its initial configuration
+		 */
+		if (adapter->mac_table[i].state & IGC_MAC_STATE_DEFAULT) {
+			adapter->mac_table[i].state =
+				IGC_MAC_STATE_DEFAULT | IGC_MAC_STATE_IN_USE;
+			adapter->mac_table[i].queue = 0;
+		} else {
+			adapter->mac_table[i].state = 0;
+			adapter->mac_table[i].queue = 0;
+			memset(adapter->mac_table[i].addr, 0, ETH_ALEN);
+		}
+
+		igc_rar_set_index(adapter, i);
+		return 0;
+	}
+
+	return -ENOENT;
+}
+
+static int igc_uc_sync(struct net_device *netdev, const unsigned char *addr)
+{
+	struct igc_adapter *adapter = netdev_priv(netdev);
+	int ret;
+
+	ret = igc_add_mac_filter(adapter, addr, adapter->num_rx_queues);
+
+	return min_t(int, ret, 0);
+}
+
+static int igc_uc_unsync(struct net_device *netdev, const unsigned char *addr)
+{
+	struct igc_adapter *adapter = netdev_priv(netdev);
+
+	igc_del_mac_filter(adapter, addr, adapter->num_rx_queues);
+
+	return 0;
+}
+
 /**
  * igc_set_rx_mode - Secondary Unicast, Multicast and Promiscuous mode set
  * @netdev: network interface device structure
@@ -2529,6 +2671,44 @@ int igc_del_mac_steering_filter(struct igc_adapter *adapter,
  */
 static void igc_set_rx_mode(struct net_device *netdev)
 {
+	struct igc_adapter *adapter = netdev_priv(netdev);
+	struct igc_hw *hw = &adapter->hw;
+	u32 rctl = 0, rlpml = MAX_JUMBO_FRAME_SIZE;
+	int count;
+
+	/* Check for Promiscuous and All Multicast modes */
+	if (netdev->flags & IFF_PROMISC) {
+		rctl |= IGC_RCTL_UPE | IGC_RCTL_MPE;
+	} else {
+		if (netdev->flags & IFF_ALLMULTI) {
+			rctl |= IGC_RCTL_MPE;
+		} else {
+			/* Write addresses to the MTA, if the attempt fails
+			 * then we should just turn on promiscuous mode so
+			 * that we can at least receive multicast traffic
+			 */
+			count = igc_write_mc_addr_list(netdev);
+			if (count < 0)
+				rctl |= IGC_RCTL_MPE;
+		}
+	}
+
+	/* Write addresses to available RAR registers, if there is not
+	 * sufficient space to store all the addresses then enable
+	 * unicast promiscuous mode
+	 */
+	if (__dev_uc_sync(netdev, igc_uc_sync, igc_uc_unsync))
+		rctl |= IGC_RCTL_UPE;
+
+	/* update state of unicast and multicast */
+	rctl |= rd32(IGC_RCTL) & ~(IGC_RCTL_UPE | IGC_RCTL_MPE);
+	wr32(IGC_RCTL, rctl);
+
+#if (PAGE_SIZE < 8192)
+	if (adapter->max_frame_size <= IGC_MAX_FRAME_BUILD_SKB)
+		rlpml = IGC_MAX_FRAME_BUILD_SKB;
+#endif
+	wr32(IGC_RLPML, rlpml);
 }
 
 /**
@@ -3982,6 +4162,7 @@ static const struct net_device_ops igc_netdev_ops = {
 	.ndo_open		= igc_open,
 	.ndo_stop		= igc_close,
 	.ndo_start_xmit		= igc_xmit_frame,
+	.ndo_set_rx_mode	= igc_set_rx_mode,
 	.ndo_set_mac_address	= igc_set_mac,
 	.ndo_change_mtu		= igc_change_mtu,
 	.ndo_get_stats		= igc_get_stats,