net/designware: ensure cache invalidations are aligned to ARCH_DMA_MINALIGN

This is required at least on ARM.

When sending instead of simply invalidating the entire descriptor, flush
as little as possible while still respecting ARCH_DMA_MINALIGN, as
requested by Alexey.

Signed-off-by: Ian Campbell <ijc@hellion.org.uk>
Cc: Alexey Brodkin <abrodkin@synopsys.com>

diff --git a/drivers/net/designware.c b/drivers/net/designware.c
index 41ab3ac0b6fd0cb9d72a9d03ac0d0526bf9edc6e..fa816bf2f6c700890b513431ade043c66c81ff39 100644 (file)
--- a/drivers/net/designware.c
+++ b/drivers/net/designware.c
@@ -280,10 +280,18 @@ static int dw_eth_send(struct eth_device *dev, void *packet, int length)
        u32 desc_num = priv->tx_currdescnum;
        struct dmamacdescr *desc_p = &priv->tx_mac_descrtable[desc_num];
 
-       /* Invalidate only "status" field for the following check */
-       invalidate_dcache_range((unsigned long)&desc_p->txrx_status,
-                               (unsigned long)&desc_p->txrx_status +
-                               sizeof(desc_p->txrx_status));
+       /*
+        * Strictly we only need to invalidate the "txrx_status" field
+        * for the following check, but on some platforms we cannot
+        * invalidate only 4 bytes, so roundup to
+        * ARCH_DMA_MINALIGN. This is safe because the individual
+        * descriptors in the array are each aligned to
+        * ARCH_DMA_MINALIGN.
+        */
+       invalidate_dcache_range(
+               (unsigned long)desc_p,
+               (unsigned long)desc_p +
+               roundup(sizeof(desc_p->txrx_status), ARCH_DMA_MINALIGN));
 
        /* Check if the descriptor is owned by CPU */
        if (desc_p->txrx_status & DESC_TXSTS_OWNBYDMA) {
@@ -351,7 +359,7 @@ static int dw_eth_recv(struct eth_device *dev)
                /* Invalidate received data */
                invalidate_dcache_range((unsigned long)desc_p->dmamac_addr,
                                        (unsigned long)desc_p->dmamac_addr +
-                                       length);
+                                       roundup(length, ARCH_DMA_MINALIGN));
 
                NetReceive(desc_p->dmamac_addr, length);