net: mvpp2: add and use accessors for TX/RX descriptors

The PPv2.2 IP has a different TX and RX descriptor layout compared to
PPv2.1. In order to prepare for the introduction of PPv2.2 support in
mvpp2, this commit adds accessors for the different fields of the TX
and RX descriptors, and changes the code to use them.

For now, the mvpp2_port argument passed to the accessors is not used,
but it will be used in follow-up to update the descriptor according to
the version of the IP being used.

Apart from the mechanical changes to use the newly introduced
accessors, a few other changes, needed to use the accessors, are made:

- The mvpp2_txq_inc_put() function now takes a mvpp2_port as first
  argument, as it is needed to use the accessors.

- Similarly, the mvpp2_bm_cookie_build() gains a mvpp2_port first
  argument, for the same reason.

- In mvpp2_rx_error(), instead of accessing the RX descriptor in each
  case of the switch, we introduce a local variable to store the
  packet size.

- Similarly, in mvpp2_buff_hdr_rx(), we introduce a local "cookie"
  variable to store the RX descriptor cookie, rather than accessing
  it from the descriptor each time.

- In mvpp2_tx_frag_process() and mvpp2_tx() instead of accessing the
  packet size from the TX descriptor, we use the actual value
  available in the function, which is used to set the TX descriptor
  packet size a few lines before.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Stefan Roese <sr@denx.de>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

drivers/net/mvpp2.c

@@ -1016,6 +1016,65 @@ static u32 mvpp2_read(struct mvpp2 *priv, u32 offset)
 	return readl(priv->base + offset);
 }
 
+static void mvpp2_txdesc_dma_addr_set(struct mvpp2_port *port,
+				      struct mvpp2_tx_desc *tx_desc,
+				      dma_addr_t dma_addr)
+{
+	tx_desc->buf_dma_addr = dma_addr;
+}
+
+static void mvpp2_txdesc_size_set(struct mvpp2_port *port,
+				  struct mvpp2_tx_desc *tx_desc,
+				  size_t size)
+{
+	tx_desc->data_size = size;
+}
+
+static void mvpp2_txdesc_txq_set(struct mvpp2_port *port,
+				 struct mvpp2_tx_desc *tx_desc,
+				 unsigned int txq)
+{
+	tx_desc->phys_txq = txq;
+}
+
+static void mvpp2_txdesc_cmd_set(struct mvpp2_port *port,
+				 struct mvpp2_tx_desc *tx_desc,
+				 unsigned int command)
+{
+	tx_desc->command = command;
+}
+
+static void mvpp2_txdesc_offset_set(struct mvpp2_port *port,
+				    struct mvpp2_tx_desc *tx_desc,
+				    unsigned int offset)
+{
+	tx_desc->packet_offset = offset;
+}
+
+static dma_addr_t mvpp2_rxdesc_dma_addr_get(struct mvpp2_port *port,
+					    struct mvpp2_rx_desc *rx_desc)
+{
+	return rx_desc->buf_dma_addr;
+}
+
+static unsigned long mvpp2_rxdesc_cookie_get(struct mvpp2_port *port,
+					     struct mvpp2_rx_desc *rx_desc)
+{
+	return rx_desc->buf_cookie;
+}
+
+static size_t mvpp2_rxdesc_size_get(struct mvpp2_port *port,
+				    struct mvpp2_rx_desc *rx_desc)
+{
+	return rx_desc->data_size;
+}
+
+static u32 mvpp2_rxdesc_status_get(struct mvpp2_port *port,
+				   struct mvpp2_rx_desc *rx_desc)
+{
+	return rx_desc->status;
+}
+
 static void mvpp2_txq_inc_get(struct mvpp2_txq_pcpu *txq_pcpu)
 {
 	txq_pcpu->txq_get_index++;
@@ -2779,11 +2838,15 @@ static void mvpp2_rxq_offset_set(struct mvpp2_port *port,
 }
 
 /* Obtain BM cookie information from descriptor */
-static u32 mvpp2_bm_cookie_build(struct mvpp2_rx_desc *rx_desc)
+static u32 mvpp2_bm_cookie_build(struct mvpp2_port *port,
+				 struct mvpp2_rx_desc *rx_desc)
 {
-	int pool = (rx_desc->status & MVPP2_RXD_BM_POOL_ID_MASK) >>
-		   MVPP2_RXD_BM_POOL_ID_OFFS;
 	int cpu = smp_processor_id();
+	int pool;
+
+	pool = (mvpp2_rxdesc_status_get(port, rx_desc) &
+		MVPP2_RXD_BM_POOL_ID_MASK) >>
+		MVPP2_RXD_BM_POOL_ID_OFFS;
 
 	return ((pool & 0xFF) << MVPP2_BM_COOKIE_POOL_OFFS) |
 	       ((cpu & 0xFF) << MVPP2_BM_COOKIE_CPU_OFFS);
@@ -3005,10 +3068,11 @@ static void mvpp2_rxq_drop_pkts(struct mvpp2_port *port,
 
 	for (i = 0; i < rx_received; i++) {
 		struct mvpp2_rx_desc *rx_desc = mvpp2_rxq_next_desc_get(rxq);
-		u32 bm = mvpp2_bm_cookie_build(rx_desc);
+		u32 bm = mvpp2_bm_cookie_build(port, rx_desc);
 
-		mvpp2_pool_refill(port, bm, rx_desc->buf_dma_addr,
-				  rx_desc->buf_cookie);
+		mvpp2_pool_refill(port, bm,
+				  mvpp2_rxdesc_dma_addr_get(port, rx_desc),
+				  mvpp2_rxdesc_cookie_get(port, rx_desc));
 	}
 	mvpp2_rxq_status_update(port, rxq->id, rx_received, rx_received);
 }
@@ -3302,20 +3366,21 @@ static void mvpp2_link_event(struct mvpp2_port *port)
 static void mvpp2_rx_error(struct mvpp2_port *port,
 			   struct mvpp2_rx_desc *rx_desc)
 {
-	u32 status = rx_desc->status;
+	u32 status = mvpp2_rxdesc_status_get(port, rx_desc);
+	size_t sz = mvpp2_rxdesc_size_get(port, rx_desc);
 
 	switch (status & MVPP2_RXD_ERR_CODE_MASK) {
 	case MVPP2_RXD_ERR_CRC:
-		netdev_err(port->dev, "bad rx status %08x (crc error), size=%d\n",
-			   status, rx_desc->data_size);
+		netdev_err(port->dev, "bad rx status %08x (crc error), size=%zu\n",
+			   status, sz);
 		break;
 	case MVPP2_RXD_ERR_OVERRUN:
-		netdev_err(port->dev, "bad rx status %08x (overrun error), size=%d\n",
-			   status, rx_desc->data_size);
+		netdev_err(port->dev, "bad rx status %08x (overrun error), size=%zu\n",
+			   status, sz);
 		break;
 	case MVPP2_RXD_ERR_RESOURCE:
-		netdev_err(port->dev, "bad rx status %08x (resource error), size=%d\n",
-			   status, rx_desc->data_size);
+		netdev_err(port->dev, "bad rx status %08x (resource error), size=%zu\n",
+			   status, sz);
 		break;
 	}
 }
@@ -3873,11 +3938,12 @@ static int mvpp2_recv(struct udevice *dev, int flags, uchar **packetp)
 		return 0;
 
 	rx_desc = mvpp2_rxq_next_desc_get(rxq);
-	rx_status = rx_desc->status;
-	rx_bytes = rx_desc->data_size - MVPP2_MH_SIZE;
-	dma_addr = rx_desc->buf_dma_addr;
+	rx_status = mvpp2_rxdesc_status_get(port, rx_desc);
+	rx_bytes = mvpp2_rxdesc_size_get(port, rx_desc);
+	rx_bytes -= MVPP2_MH_SIZE;
+	dma_addr = mvpp2_rxdesc_dma_addr_get(port, rx_desc);
 
-	bm = mvpp2_bm_cookie_build(rx_desc);
+	bm = mvpp2_bm_cookie_build(port, rx_desc);
 	pool = mvpp2_bm_cookie_pool_get(bm);
 	bm_pool = &port->priv->bm_pools[pool];
 
@@ -3889,8 +3955,7 @@ static int mvpp2_recv(struct udevice *dev, int flags, uchar **packetp)
 	if (rx_status & MVPP2_RXD_ERR_SUMMARY) {
 		mvpp2_rx_error(port, rx_desc);
 		/* Return the buffer to the pool */
-		mvpp2_pool_refill(port, bm, rx_desc->buf_dma_addr,
-				  rx_desc->buf_cookie);
+		mvpp2_pool_refill(port, bm, dma_addr, dma_addr);
 		return 0;
 	}
 
@@ -3947,13 +4012,16 @@ static int mvpp2_send(struct udevice *dev, void *packet, int length)
 
 	/* Get a descriptor for the first part of the packet */
 	tx_desc = mvpp2_txq_next_desc_get(aggr_txq);
-	tx_desc->phys_txq = txq->id;
-	tx_desc->data_size = length;
-	tx_desc->packet_offset = (unsigned long)packet & MVPP2_TX_DESC_ALIGN;
-	tx_desc->buf_dma_addr = (unsigned long)packet & ~MVPP2_TX_DESC_ALIGN;
+	mvpp2_txdesc_txq_set(port, tx_desc, txq->id);
+	mvpp2_txdesc_size_set(port, tx_desc, length);
+	mvpp2_txdesc_offset_set(port, tx_desc,
+				(dma_addr_t)packet & MVPP2_TX_DESC_ALIGN);
+	mvpp2_txdesc_dma_addr_set(port, tx_desc,
+				  (dma_addr_t)packet & ~MVPP2_TX_DESC_ALIGN);
 	/* First and Last descriptor */
-	tx_desc->command = MVPP2_TXD_L4_CSUM_NOT | MVPP2_TXD_IP_CSUM_DISABLE
-		| MVPP2_TXD_F_DESC | MVPP2_TXD_L_DESC;
+	mvpp2_txdesc_cmd_set(port, tx_desc,
+			     MVPP2_TXD_L4_CSUM_NOT | MVPP2_TXD_IP_CSUM_DISABLE
+			     | MVPP2_TXD_F_DESC | MVPP2_TXD_L_DESC);
 
 	/* Flush tx data */
 	flush_dcache_range((unsigned long)packet,