Revert "net: bcmgenet: remove unused function in bcmgenet.c"

This reverts commit e2072600.

This commit restores the previous implementation of Hardware Filter
Block functions to the file for use in subsequent commits.
Signed-off-by: Doug Berger <opendmb@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/genet/bcmgenet.c

@@ -2759,6 +2759,128 @@ static void bcmgenet_enable_dma(struct bcmgenet_priv *priv, u32 dma_ctrl)
 	bcmgenet_tdma_writel(priv, reg, DMA_CTRL);
 }
 
+static bool bcmgenet_hfb_is_filter_enabled(struct bcmgenet_priv *priv,
+					   u32 f_index)
+{
+	u32 offset;
+	u32 reg;
+
+	offset = HFB_FLT_ENABLE_V3PLUS + (f_index < 32) * sizeof(u32);
+	reg = bcmgenet_hfb_reg_readl(priv, offset);
+	return !!(reg & (1 << (f_index % 32)));
+}
+
+static void bcmgenet_hfb_enable_filter(struct bcmgenet_priv *priv, u32 f_index)
+{
+	u32 offset;
+	u32 reg;
+
+	offset = HFB_FLT_ENABLE_V3PLUS + (f_index < 32) * sizeof(u32);
+	reg = bcmgenet_hfb_reg_readl(priv, offset);
+	reg |= (1 << (f_index % 32));
+	bcmgenet_hfb_reg_writel(priv, reg, offset);
+}
+
+static void bcmgenet_hfb_set_filter_rx_queue_mapping(struct bcmgenet_priv *priv,
+						     u32 f_index, u32 rx_queue)
+{
+	u32 offset;
+	u32 reg;
+
+	offset = f_index / 8;
+	reg = bcmgenet_rdma_readl(priv, DMA_INDEX2RING_0 + offset);
+	reg &= ~(0xF << (4 * (f_index % 8)));
+	reg |= ((rx_queue & 0xF) << (4 * (f_index % 8)));
+	bcmgenet_rdma_writel(priv, reg, DMA_INDEX2RING_0 + offset);
+}
+
+static void bcmgenet_hfb_set_filter_length(struct bcmgenet_priv *priv,
+					   u32 f_index, u32 f_length)
+{
+	u32 offset;
+	u32 reg;
+
+	offset = HFB_FLT_LEN_V3PLUS +
+		 ((priv->hw_params->hfb_filter_cnt - 1 - f_index) / 4) *
+		 sizeof(u32);
+	reg = bcmgenet_hfb_reg_readl(priv, offset);
+	reg &= ~(0xFF << (8 * (f_index % 4)));
+	reg |= ((f_length & 0xFF) << (8 * (f_index % 4)));
+	bcmgenet_hfb_reg_writel(priv, reg, offset);
+}
+
+static int bcmgenet_hfb_find_unused_filter(struct bcmgenet_priv *priv)
+{
+	u32 f_index;
+
+	for (f_index = 0; f_index < priv->hw_params->hfb_filter_cnt; f_index++)
+		if (!bcmgenet_hfb_is_filter_enabled(priv, f_index))
+			return f_index;
+
+	return -ENOMEM;
+}
+
+/* bcmgenet_hfb_add_filter
+ *
+ * Add new filter to Hardware Filter Block to match and direct Rx traffic to
+ * desired Rx queue.
+ *
+ * f_data is an array of unsigned 32-bit integers where each 32-bit integer
+ * provides filter data for 2 bytes (4 nibbles) of Rx frame:
+ *
+ * bits 31:20 - unused
+ * bit  19    - nibble 0 match enable
+ * bit  18    - nibble 1 match enable
+ * bit  17    - nibble 2 match enable
+ * bit  16    - nibble 3 match enable
+ * bits 15:12 - nibble 0 data
+ * bits 11:8  - nibble 1 data
+ * bits 7:4   - nibble 2 data
+ * bits 3:0   - nibble 3 data
+ *
+ * Example:
+ * In order to match:
+ * - Ethernet frame type = 0x0800 (IP)
+ * - IP version field = 4
+ * - IP protocol field = 0x11 (UDP)
+ *
+ * The following filter is needed:
+ * u32 hfb_filter_ipv4_udp[] = {
+ *   Rx frame offset 0x00: 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+ *   Rx frame offset 0x08: 0x00000000, 0x00000000, 0x000F0800, 0x00084000,
+ *   Rx frame offset 0x10: 0x00000000, 0x00000000, 0x00000000, 0x00030011,
+ * };
+ *
+ * To add the filter to HFB and direct the traffic to Rx queue 0, call:
+ * bcmgenet_hfb_add_filter(priv, hfb_filter_ipv4_udp,
+ *                         ARRAY_SIZE(hfb_filter_ipv4_udp), 0);
+ */
+int bcmgenet_hfb_add_filter(struct bcmgenet_priv *priv, u32 *f_data,
+			    u32 f_length, u32 rx_queue)
+{
+	int f_index;
+	u32 i;
+
+	f_index = bcmgenet_hfb_find_unused_filter(priv);
+	if (f_index < 0)
+		return -ENOMEM;
+
+	if (f_length > priv->hw_params->hfb_filter_size)
+		return -EINVAL;
+
+	for (i = 0; i < f_length; i++)
+		bcmgenet_hfb_writel(priv, f_data[i],
+			(f_index * priv->hw_params->hfb_filter_size + i) *
+			sizeof(u32));
+
+	bcmgenet_hfb_set_filter_length(priv, f_index, 2 * f_length);
+	bcmgenet_hfb_set_filter_rx_queue_mapping(priv, f_index, rx_queue);
+	bcmgenet_hfb_enable_filter(priv, f_index);
+	bcmgenet_hfb_reg_writel(priv, 0x1, HFB_CTRL);
+
+	return 0;
+}
+
 /* bcmgenet_hfb_clear
  *
  * Clear Hardware Filter Block and disable all filtering.