pcnet: align rx buffers for cache invalidation

The RX buffers are invalidated when a packet is received, however they
were not suitably cache-line aligned. Allocate them seperately to the
pcnet_priv structure and align to ARCH_DMA_MINALIGN in order to ensure
suitable alignment for the cache invalidation, preventing anything else
being placed in the same lines & lost.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>

diff --git a/drivers/net/pcnet.c b/drivers/net/pcnet.c
index 8c334c7abcc9a8077c2a638d985a628d9f791926..2802411db19fafbfa0bec52d99321bbd76c5b545 100644 (file)
--- a/drivers/net/pcnet.c
+++ b/drivers/net/pcnet.c
@@ -80,7 +80,7 @@ struct pcnet_uncached_priv {
 typedef struct pcnet_priv {
        struct pcnet_uncached_priv *uc;
        /* Receive Buffer space */
-       unsigned char rx_buf[RX_RING_SIZE][PKT_BUF_SZ + 4];
+       unsigned char (*rx_buf)[RX_RING_SIZE][PKT_BUF_SZ + 4];
        int cur_rx;
        int cur_tx;
 } pcnet_priv_t;
@@ -335,6 +335,10 @@ static int pcnet_init(struct eth_device *dev, bd_t *bis)
                flush_dcache_range(addr, addr + sizeof(*lp->uc));
                addr = UNCACHED_SDRAM(addr);
                lp->uc = (struct pcnet_uncached_priv *)addr;
+
+               addr = (u32)memalign(ARCH_DMA_MINALIGN, sizeof(*lp->rx_buf));
+               flush_dcache_range(addr, addr + sizeof(*lp->rx_buf));
+               lp->rx_buf = (void *)addr;
        }
 
        uc = lp->uc;
@@ -348,7 +352,7 @@ static int pcnet_init(struct eth_device *dev, bd_t *bis)
         */
        lp->cur_rx = 0;
        for (i = 0; i < RX_RING_SIZE; i++) {
-               uc->rx_ring[i].base = PCI_TO_MEM_LE(dev, lp->rx_buf[i]);
+               uc->rx_ring[i].base = PCI_TO_MEM_LE(dev, (*lp->rx_buf)[i]);
                uc->rx_ring[i].buf_length = cpu_to_le16(-PKT_BUF_SZ);
                uc->rx_ring[i].status = cpu_to_le16(0x8000);
                PCNET_DEBUG1
@@ -467,6 +471,7 @@ static int pcnet_send(struct eth_device *dev, void *packet, int pkt_len)
 static int pcnet_recv (struct eth_device *dev)
 {
        struct pcnet_rx_head *entry;
+       unsigned char *buf;
        int pkt_len = 0;
        u16 status;
 
@@ -500,14 +505,12 @@ static int pcnet_recv (struct eth_device *dev)
                                printf("%s: Rx%d: invalid packet length %d\n",
                                       dev->name, lp->cur_rx, pkt_len);
                        } else {
-                               invalidate_dcache_range(
-                                       (unsigned long)lp->rx_buf[lp->cur_rx],
-                                       (unsigned long)lp->rx_buf[lp->cur_rx] +
-                                       pkt_len);
-                               NetReceive(lp->rx_buf[lp->cur_rx], pkt_len);
+                               buf = (*lp->rx_buf)[lp->cur_rx];
+                               invalidate_dcache_range((unsigned long)buf,
+                                       (unsigned long)buf + pkt_len);
+                               NetReceive(buf, pkt_len);
                                PCNET_DEBUG2("Rx%d: %d bytes from 0x%p\n",
-                                            lp->cur_rx, pkt_len,
-                                            lp->rx_buf[lp->cur_rx]);
+                                            lp->cur_rx, pkt_len, buf);
                        }
                }
                entry->status |= cpu_to_le16(0x8000);