net: mvpp2: add buffer header handling in RX

If Link Partner sends frames larger than RX buffer size, MAC mark it
as oversize but still would pass it to the Packet Processor.
In this scenario, Packet Processor scatter frame between multiple buffers,
but only a single buffer would be returned to the Buffer Manager pool and
it would not refill the poll.

Patch add handling of oversize error with buffer header handling, so all
buffers would be returned to the Buffer Manager pool.

Fixes: 3f518509dedc ("ethernet: Add new driver for Marvell Armada 375 network unit")
Reported-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Stefan Chulski <stefanc@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 45 insertions, 9 deletions

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index ec706d614cac..d39c7639cdba 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -3839,6 +3839,35 @@ mvpp2_run_xdp(struct mvpp2_port *port, struct mvpp2_rx_queue *rxq,
 	return ret;
 }
 
+static void mvpp2_buff_hdr_pool_put(struct mvpp2_port *port, struct mvpp2_rx_desc *rx_desc,
+				    int pool, u32 rx_status)
+{
+	phys_addr_t phys_addr, phys_addr_next;
+	dma_addr_t dma_addr, dma_addr_next;
+	struct mvpp2_buff_hdr *buff_hdr;
+
+	phys_addr = mvpp2_rxdesc_dma_addr_get(port, rx_desc);
+	dma_addr = mvpp2_rxdesc_cookie_get(port, rx_desc);
+
+	do {
+		buff_hdr = (struct mvpp2_buff_hdr *)phys_to_virt(phys_addr);
+
+		phys_addr_next = le32_to_cpu(buff_hdr->next_phys_addr);
+		dma_addr_next = le32_to_cpu(buff_hdr->next_dma_addr);
+
+		if (port->priv->hw_version >= MVPP22) {
+			phys_addr_next |= ((u64)buff_hdr->next_phys_addr_high << 32);
+			dma_addr_next |= ((u64)buff_hdr->next_dma_addr_high << 32);
+		}
+
+		mvpp2_bm_pool_put(port, pool, dma_addr, phys_addr);
+
+		phys_addr = phys_addr_next;
+		dma_addr = dma_addr_next;
+
+	} while (!MVPP2_B_HDR_INFO_IS_LAST(le16_to_cpu(buff_hdr->info)));
+}
+
 /* Main rx processing */
 static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi,
 		    int rx_todo, struct mvpp2_rx_queue *rxq)
@@ -3885,14 +3914,6 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi,
 			MVPP2_RXD_BM_POOL_ID_OFFS;
 		bm_pool = &port->priv->bm_pools[pool];
 
-		/* In case of an error, release the requested buffer pointer
-		 * to the Buffer Manager. This request process is controlled
-		 * by the hardware, and the information about the buffer is
-		 * comprised by the RX descriptor.
-		 */
-		if (rx_status & MVPP2_RXD_ERR_SUMMARY)
-			goto err_drop_frame;
-
 		if (port->priv->percpu_pools) {
 			pp = port->priv->page_pool[pool];
 			dma_dir = page_pool_get_dma_dir(pp);
@@ -3904,6 +3925,18 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi,
 					rx_bytes + MVPP2_MH_SIZE,
 					dma_dir);
 
+		/* Buffer header not supported */
+		if (rx_status & MVPP2_RXD_BUF_HDR)
+			goto err_drop_frame;
+
+		/* In case of an error, release the requested buffer pointer
+		 * to the Buffer Manager. This request process is controlled
+		 * by the hardware, and the information about the buffer is
+		 * comprised by the RX descriptor.
+		 */
+		if (rx_status & MVPP2_RXD_ERR_SUMMARY)
+			goto err_drop_frame;
+
 		/* Prefetch header */
 		prefetch(data);
 
@@ -3985,7 +4018,10 @@ err_drop_frame:
 		dev->stats.rx_errors++;
 		mvpp2_rx_error(port, rx_desc);
 		/* Return the buffer to the pool */
-		mvpp2_bm_pool_put(port, pool, dma_addr, phys_addr);
+		if (rx_status & MVPP2_RXD_BUF_HDR)
+			mvpp2_buff_hdr_pool_put(port, rx_desc, pool, rx_status);
+		else
+			mvpp2_bm_pool_put(port, pool, dma_addr, phys_addr);
 	}
 
 	rcu_read_unlock();