[U-Boot] [PATCH v2 1/2] mvebu: neta: align DMA buffers

[Baruch Siach]

From: Jon Nettleton <jon at solid-run.com>

This makes sure the DMA buffers are properly aligned for the
hardware.

Reviewed-by: Stefan Roese <sr at denx.de>
Signed-off-by: Jon Nettleton <jon at solid-run.com>
Signed-off-by: Baruch Siach <baruch at tkos.co.il>
---
v2:
  * Change BUG_ON to WARN_ON (Stefan Roese)

  * Add Stefan's review tag
---
 drivers/net/mvneta.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/net/mvneta.c b/drivers/net/mvneta.c
index 7036b517b445..45e5eda95522 100644
--- a/drivers/net/mvneta.c
+++ b/drivers/net/mvneta.c
@@ -1025,6 +1025,8 @@ static int mvneta_rxq_init(struct mvneta_port *pp,
 	if (rxq->descs == NULL)
 		return -ENOMEM;
 
+	WARN_ON(rxq->descs != PTR_ALIGN(rxq->descs, ARCH_DMA_MINALIGN));
+
 	rxq->last_desc = rxq->size - 1;
 
 	/* Set Rx descriptors queue starting address */
@@ -1061,6 +1063,8 @@ static int mvneta_txq_init(struct mvneta_port *pp,
 	if (txq->descs == NULL)
 		return -ENOMEM;
 
+	WARN_ON(txq->descs != PTR_ALIGN(txq->descs, ARCH_DMA_MINALIGN));
+
 	txq->last_desc = txq->size - 1;
 
 	/* Set maximum bandwidth for enabled TXQs */
@@ -1694,18 +1698,20 @@ static int mvneta_probe(struct udevice *dev)
 	 * be active. Make this area DMA safe by disabling the D-cache
 	 */
 	if (!buffer_loc.tx_descs) {
+		u32 size;
+
 		/* Align buffer area for descs and rx_buffers to 1MiB */
 		bd_space = memalign(1 << MMU_SECTION_SHIFT, BD_SPACE);
 		mmu_set_region_dcache_behaviour((phys_addr_t)bd_space, BD_SPACE,
 						DCACHE_OFF);
 		buffer_loc.tx_descs = (struct mvneta_tx_desc *)bd_space;
+		size = roundup(MVNETA_MAX_TXD * sizeof(struct mvneta_tx_desc),
+				ARCH_DMA_MINALIGN);
 		buffer_loc.rx_descs = (struct mvneta_rx_desc *)
-			((phys_addr_t)bd_space +
-			 MVNETA_MAX_TXD * sizeof(struct mvneta_tx_desc));
-		buffer_loc.rx_buffers = (phys_addr_t)
-			(bd_space +
-			 MVNETA_MAX_TXD * sizeof(struct mvneta_tx_desc) +
-			 MVNETA_MAX_RXD * sizeof(struct mvneta_rx_desc));
+			((phys_addr_t)bd_space + size);
+		size += roundup(MVNETA_MAX_RXD * sizeof(struct mvneta_rx_desc),
+				ARCH_DMA_MINALIGN);
+		buffer_loc.rx_buffers = (phys_addr_t)(bd_space + size);
 	}
 
 	pp->base = (void __iomem *)pdata->iobase;
-- 
2.17.0