On Mon, 13 Feb 2012 11:34:21 +0530
Mugunthan V N [off-list ref] wrote:

+static ssize_t cpsw_hw_stats_show(struct device *dev,
+				     struct device_attribute *attr,
+				     char *buf)
+{
+	struct net_device	*ndev = to_net_dev(dev);
+	struct cpsw_priv	*priv = netdev_priv(ndev);
+	int			len = 0;
+	struct cpdma_chan_stats	dma_stats;
+
+#define show_stat(x) do {						\
+	len += __show_stat(buf + len, SZ_4K - len, #x,			\
+			   __raw_readl(&priv->hw_stats->x));		\
+} while (0)
+
+#define show_dma_stat(x) do {						\
+	len += __show_stat(buf + len, SZ_4K - len, #x, dma_stats.x);	\
+} while (0)
+
+	len += snprintf(buf + len, SZ_4K - len, "CPSW Statistics:\n");
+	show_stat(rxgoodframes);	show_stat(rxbroadcastframes);
+	show_stat(rxmulticastframes);	show_stat(rxpauseframes);
+	show_stat(rxcrcerrors);		show_stat(rxaligncodeerrors);
+	show_stat(rxoversizedframes);	show_stat(rxjabberframes);
+	show_stat(rxundersizedframes);	show_stat(rxfragments);
+	show_stat(rxoctets);		show_stat(txgoodframes);
+	show_stat(txbroadcastframes);	show_stat(txmulticastframes);
+	show_stat(txpauseframes);	show_stat(txdeferredframes);
+	show_stat(txcollisionframes);	show_stat(txsinglecollframes);
+	show_stat(txmultcollframes);	show_stat(txexcessivecollisions);
+	show_stat(txlatecollisions);	show_stat(txunderrun);
+	show_stat(txcarriersenseerrors); show_stat(txoctets);
+	show_stat(octetframes64);	show_stat(octetframes65t127);
+	show_stat(octetframes128t255);	show_stat(octetframes256t511);
+	show_stat(octetframes512t1023);	show_stat(octetframes1024tup);
+	show_stat(netoctets);		show_stat(rxsofoverruns);
+	show_stat(rxmofoverruns);	show_stat(rxdmaoverruns);
+
+	cpdma_chan_get_stats(priv->rxch, &dma_stats);
+	len += snprintf(buf + len, SZ_4K - len, "\nRX DMA Statistics:\n");
+	show_dma_stat(head_enqueue);	show_dma_stat(tail_enqueue);
+	show_dma_stat(pad_enqueue);	show_dma_stat(misqueued);
+	show_dma_stat(desc_alloc_fail);	show_dma_stat(pad_alloc_fail);
+	show_dma_stat(runt_receive_buff); show_dma_stat(runt_transmit_buff);
+	show_dma_stat(empty_dequeue);	show_dma_stat(busy_dequeue);
+	show_dma_stat(good_dequeue);	show_dma_stat(teardown_dequeue);
+
+	cpdma_chan_get_stats(priv->txch, &dma_stats);
+	len += snprintf(buf + len, SZ_4K - len, "\nTX DMA Statistics:\n");
+	show_dma_stat(head_enqueue);	show_dma_stat(tail_enqueue);
+	show_dma_stat(pad_enqueue);	show_dma_stat(misqueued);
+	show_dma_stat(desc_alloc_fail);	show_dma_stat(pad_alloc_fail);
+	show_dma_stat(runt_receive_buff); show_dma_stat(runt_transmit_buff);
+	show_dma_stat(empty_dequeue);	show_dma_stat(busy_dequeue);
+	show_dma_stat(good_dequeue);	show_dma_stat(teardown_dequeue);
+
+	return len;
+}
+
+DEVICE_ATTR(hw_stats, S_IRUGO, cpsw_hw_stats_show, NULL);
+

These stats belong in ethtool, not sysfs.