net: mvpp2: fix second cp110 initialization

Since the mdio code got upstreamed it is not possible
to activate network ports on CP110 Master and Slave.

The problem is in mvpp2_base_probe which is called for each
CP110 and it initializes the buffer area for descs and rx_buffers.

This should only happen once though and the bd space is actually
set to 0 after the first run of the function.

This leads to an error when the second CP110 tries the initialization
again and disables all network ports on this CP110.

This patch adds a static variable to check if the buffer area is
initialized only once globally.
Signed-off-by: NSven Auhagen <sven.auhagen@voleatech.de>
Reviewed-by: NStefan Roese <sr@denx.de>

drivers/net/mvpp2.c

@@ -1263,6 +1263,7 @@ struct buffer_location {
  * can be enabled at once
  */
 static struct buffer_location buffer_loc;
+static int buffer_loc_init;
 
 /*
  * Page table entries are set to 1MB, or multiples of 1MB
@@ -5247,40 +5248,44 @@ static int mvpp2_base_probe(struct udevice *dev)
 	 * be active. Make this area DMA-safe by disabling the D-cache
 	 */
 
-	/* Align buffer area for descs and rx_buffers to 1MiB */
-	bd_space = memalign(1 << MMU_SECTION_SHIFT, BD_SPACE);
-	mmu_set_region_dcache_behaviour((unsigned long)bd_space,
-					BD_SPACE, DCACHE_OFF);
-
-	buffer_loc.aggr_tx_descs = (struct mvpp2_tx_desc *)bd_space;
-	size += MVPP2_AGGR_TXQ_SIZE * MVPP2_DESC_ALIGNED_SIZE;
-
-	buffer_loc.tx_descs =
-		(struct mvpp2_tx_desc *)((unsigned long)bd_space + size);
-	size += MVPP2_MAX_TXD * MVPP2_DESC_ALIGNED_SIZE;
+	if (!buffer_loc_init) {
+		/* Align buffer area for descs and rx_buffers to 1MiB */
+		bd_space = memalign(1 << MMU_SECTION_SHIFT, BD_SPACE);
+		mmu_set_region_dcache_behaviour((unsigned long)bd_space,
+						BD_SPACE, DCACHE_OFF);
+
+		buffer_loc.aggr_tx_descs = (struct mvpp2_tx_desc *)bd_space;
+		size += MVPP2_AGGR_TXQ_SIZE * MVPP2_DESC_ALIGNED_SIZE;
+
+		buffer_loc.tx_descs =
+			(struct mvpp2_tx_desc *)((unsigned long)bd_space + size);
+		size += MVPP2_MAX_TXD * MVPP2_DESC_ALIGNED_SIZE;
+
+		buffer_loc.rx_descs =
+			(struct mvpp2_rx_desc *)((unsigned long)bd_space + size);
+		size += MVPP2_MAX_RXD * MVPP2_DESC_ALIGNED_SIZE;
+
+		for (i = 0; i < MVPP2_BM_POOLS_NUM; i++) {
+			buffer_loc.bm_pool[i] =
+				(unsigned long *)((unsigned long)bd_space + size);
+			if (priv->hw_version == MVPP21)
+				size += MVPP2_BM_POOL_SIZE_MAX * 2 * sizeof(u32);
+			else
+				size += MVPP2_BM_POOL_SIZE_MAX * 2 * sizeof(u64);
+		}
 
-	buffer_loc.rx_descs =
-		(struct mvpp2_rx_desc *)((unsigned long)bd_space + size);
-	size += MVPP2_MAX_RXD * MVPP2_DESC_ALIGNED_SIZE;
+		for (i = 0; i < MVPP2_BM_LONG_BUF_NUM; i++) {
+			buffer_loc.rx_buffer[i] =
+				(unsigned long *)((unsigned long)bd_space + size);
+			size += RX_BUFFER_SIZE;
+		}
 
-	for (i = 0; i < MVPP2_BM_POOLS_NUM; i++) {
-		buffer_loc.bm_pool[i] =
-			(unsigned long *)((unsigned long)bd_space + size);
-		if (priv->hw_version == MVPP21)
-			size += MVPP2_BM_POOL_SIZE_MAX * 2 * sizeof(u32);
-		else
-			size += MVPP2_BM_POOL_SIZE_MAX * 2 * sizeof(u64);
-	}
+		/* Clear the complete area so that all descriptors are cleared */
+		memset(bd_space, 0, size);
 
-	for (i = 0; i < MVPP2_BM_LONG_BUF_NUM; i++) {
-		buffer_loc.rx_buffer[i] =
-			(unsigned long *)((unsigned long)bd_space + size);
-		size += RX_BUFFER_SIZE;
+		buffer_loc_init = 1;
 	}
 
-	/* Clear the complete area so that all descriptors are cleared */
-	memset(bd_space, 0, size);
-
 	/* Save base addresses for later use */
 	priv->base = (void *)devfdt_get_addr_index(dev, 0);
 	if (IS_ERR(priv->base))