amd-xgbe: Implement split header receive support

Provide support for splitting IP packets so that the header and
payload can be sent to different DMA addresses.  This will allow
the IP header to be put into the linear part of the skb while the
payload can be added as frags.

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

1 files changed, 33 insertions, 11 deletions

diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-dev.c b/drivers/net/ethernet/amd/xgbe/xgbe-dev.c
index 7748b758baf6..b3719f154637 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-dev.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-dev.c
@@ -335,6 +335,22 @@ static void xgbe_config_tso_mode(struct xgbe_prv_data *pdata)
 	}
 }
 
+static void xgbe_config_sph_mode(struct xgbe_prv_data *pdata)
+{
+	struct xgbe_channel *channel;
+	unsigned int i;
+
+	channel = pdata->channel;
+	for (i = 0; i < pdata->channel_count; i++, channel++) {
+		if (!channel->rx_ring)
+			break;
+
+		XGMAC_DMA_IOWRITE_BITS(channel, DMA_CH_CR, SPH, 1);
+	}
+
+	XGMAC_IOWRITE_BITS(pdata, MAC_RCR, HDSMS, XGBE_SPH_HDSMS_SIZE);
+}
+
 static int xgbe_disable_tx_flow_control(struct xgbe_prv_data *pdata)
 {
 	unsigned int max_q_count, q_count;
@@ -920,19 +936,19 @@ static void xgbe_rx_desc_reset(struct xgbe_ring_data *rdata)
 	struct xgbe_ring_desc *rdesc = rdata->rdesc;
 
 	/* Reset the Rx descriptor
-	 *   Set buffer 1 (lo) address to dma address (lo)
-	 *   Set buffer 1 (hi) address to dma address (hi)
-	 *   Set buffer 2 (lo) address to zero
-	 *   Set buffer 2 (hi) address to zero and set control bits
-	 *     OWN and INTE
+	 *   Set buffer 1 (lo) address to header dma address (lo)
+	 *   Set buffer 1 (hi) address to header dma address (hi)
+	 *   Set buffer 2 (lo) address to buffer dma address (lo)
+	 *   Set buffer 2 (hi) address to buffer dma address (hi) and
+	 *     set control bits OWN and INTE
 	 */
-	rdesc->desc0 = cpu_to_le32(lower_32_bits(rdata->rx_dma));
-	rdesc->desc1 = cpu_to_le32(upper_32_bits(rdata->rx_dma));
-	rdesc->desc2 = 0;
+	rdesc->desc0 = cpu_to_le32(lower_32_bits(rdata->rx_hdr.dma));
+	rdesc->desc1 = cpu_to_le32(upper_32_bits(rdata->rx_hdr.dma));
+	rdesc->desc2 = cpu_to_le32(lower_32_bits(rdata->rx_buf.dma));
+	rdesc->desc3 = cpu_to_le32(upper_32_bits(rdata->rx_buf.dma));
 
-	rdesc->desc3 = 0;
-	if (rdata->interrupt)
-		XGMAC_SET_BITS_LE(rdesc->desc3, RX_NORMAL_DESC3, INTE, 1);
+	XGMAC_SET_BITS_LE(rdesc->desc3, RX_NORMAL_DESC3, INTE,
+			  rdata->interrupt ? 1 : 0);
 
 	/* Since the Rx DMA engine is likely running, make sure everything
 	 * is written to the descriptor(s) before setting the OWN bit
@@ -1422,6 +1438,11 @@ static int xgbe_dev_read(struct xgbe_channel *channel)
 		XGMAC_SET_BITS(packet->attributes, RX_PACKET_ATTRIBUTES,
 			       CONTEXT_NEXT, 1);
 
+	/* Get the header length */
+	if (XGMAC_GET_BITS_LE(rdesc->desc3, RX_NORMAL_DESC3, FD))
+		rdata->hdr_len = XGMAC_GET_BITS_LE(rdesc->desc2,
+						   RX_NORMAL_DESC2, HL);
+
 	/* Get the packet length */
 	rdata->len = XGMAC_GET_BITS_LE(rdesc->desc3, RX_NORMAL_DESC3, PL);
 
@@ -2453,6 +2474,7 @@ static int xgbe_init(struct xgbe_prv_data *pdata)
 	xgbe_config_tx_coalesce(pdata);
 	xgbe_config_rx_buffer_size(pdata);
 	xgbe_config_tso_mode(pdata);
+	xgbe_config_sph_mode(pdata);
 	desc_if->wrapper_tx_desc_init(pdata);
 	desc_if->wrapper_rx_desc_init(pdata);
 	xgbe_enable_dma_interrupts(pdata);