3 files changed, 122 insertions, 8 deletions

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index d39875e267d9..f339268da11a 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -2484,6 +2484,90 @@ static int cpsw_nway_reset(struct net_device *ndev)
 		return -EOPNOTSUPP;
 }
 
+static void cpsw_get_ringparam(struct net_device *ndev,
+			       struct ethtool_ringparam *ering)
+{
+	struct cpsw_priv *priv = netdev_priv(ndev);
+	struct cpsw_common *cpsw = priv->cpsw;
+
+	/* not supported */
+	ering->tx_max_pending = 0;
+	ering->tx_pending = cpdma_get_num_tx_descs(cpsw->dma);
+	/* Max 90% RX buffers */
+	ering->rx_max_pending = (descs_pool_size * 9) / 10;
+	ering->rx_pending = cpdma_get_num_rx_descs(cpsw->dma);
+}
+
+static int cpsw_set_ringparam(struct net_device *ndev,
+			      struct ethtool_ringparam *ering)
+{
+	struct cpsw_priv *priv = netdev_priv(ndev);
+	struct cpsw_common *cpsw = priv->cpsw;
+	struct cpsw_slave *slave;
+	int i, ret;
+
+	/* ignore ering->tx_pending - only rx_pending adjustment is supported */
+
+	if (ering->rx_mini_pending || ering->rx_jumbo_pending ||
+	    ering->rx_pending < (descs_pool_size / 10) ||
+	    ering->rx_pending > ((descs_pool_size * 9) / 10))
+		return -EINVAL;
+
+	if (ering->rx_pending == cpdma_get_num_rx_descs(cpsw->dma))
+		return 0;
+
+	/* Disable NAPI scheduling */
+	cpsw_intr_disable(cpsw);
+
+	/* Stop all transmit queues for every network device.
+	 * Disable re-using rx descriptors with dormant_on.
+	 */
+	for (i = cpsw->data.slaves, slave = cpsw->slaves; i; i--, slave++) {
+		if (!(slave->ndev && netif_running(slave->ndev)))
+			continue;
+
+		netif_tx_stop_all_queues(slave->ndev);
+		netif_dormant_on(slave->ndev);
+	}
+
+	/* Handle rest of tx packets and stop cpdma channels */
+	cpdma_ctlr_stop(cpsw->dma);
+
+	cpdma_set_num_rx_descs(cpsw->dma, ering->rx_pending);
+
+	for (i = cpsw->data.slaves, slave = cpsw->slaves; i; i--, slave++) {
+		if (!(slave->ndev && netif_running(slave->ndev)))
+			continue;
+
+		/* Enable rx packets handling */
+		netif_dormant_off(slave->ndev);
+	}
+
+	if (cpsw_common_res_usage_state(cpsw)) {
+		cpdma_chan_split_pool(cpsw->dma);
+
+		ret = cpsw_fill_rx_channels(priv);
+		if (ret)
+			goto err;
+
+		/* After this receive is started */
+		cpdma_ctlr_start(cpsw->dma);
+		cpsw_intr_enable(cpsw);
+	}
+
+	/* Resume transmit for every affected interface */
+	for (i = cpsw->data.slaves, slave = cpsw->slaves; i; i--, slave++) {
+		if (!(slave->ndev && netif_running(slave->ndev)))
+			continue;
+		netif_tx_start_all_queues(slave->ndev);
+	}
+	return 0;
+err:
+	dev_err(priv->dev, "cannot set ring params, closing device\n");
+	dev_close(ndev);
+	return ret;
+}
+
 static const struct ethtool_ops cpsw_ethtool_ops = {
 	.get_drvinfo	= cpsw_get_drvinfo,
 	.get_msglevel	= cpsw_get_msglevel,
@@ -2510,6 +2594,8 @@ static const struct ethtool_ops cpsw_ethtool_ops = {
 	.get_eee	= cpsw_get_eee,
 	.set_eee	= cpsw_set_eee,
 	.nway_reset	= cpsw_nway_reset,
+	.get_ringparam = cpsw_get_ringparam,
+	.set_ringparam = cpsw_set_ringparam,
 };
 
 static void cpsw_slave_init(struct cpsw_slave *slave, struct cpsw_common *cpsw,
diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c b/drivers/net/ethernet/ti/davinci_cpdma.c
index 65e2f124d62a..d80bff19d4ec 100644
--- a/drivers/net/ethernet/ti/davinci_cpdma.c
+++ b/drivers/net/ethernet/ti/davinci_cpdma.c
@@ -108,6 +108,8 @@ struct cpdma_ctlr {
 	spinlock_t		lock;
 	struct cpdma_chan	*channels[2 * CPDMA_MAX_CHANNELS];
 	int chan_num;
+	int			num_rx_desc; /* RX descriptors number */
+	int			num_tx_desc; /* TX descriptors number */
 };
 
 struct cpdma_chan {
@@ -518,6 +520,9 @@ struct cpdma_ctlr *cpdma_ctlr_create(struct cpdma_params *params)
 
 	if (cpdma_desc_pool_create(ctlr))
 		return NULL;
+	/* split pool equally between RX/TX by default */
+	ctlr->num_tx_desc = ctlr->pool->num_desc / 2;
+	ctlr->num_rx_desc = ctlr->pool->num_desc - ctlr->num_tx_desc;
 
 	if (WARN_ON(ctlr->num_chan > CPDMA_MAX_CHANNELS))
 		ctlr->num_chan = CPDMA_MAX_CHANNELS;
@@ -717,22 +722,22 @@ static void cpdma_chan_set_descs(struct cpdma_ctlr *ctlr,
 		}
 	}
 	/* use remains */
-	most_chan->desc_num += desc_cnt;
+	if (most_chan)
+		most_chan->desc_num += desc_cnt;
 }
 
 /**
  * cpdma_chan_split_pool - Splits ctrl pool between all channels.
  * Has to be called under ctlr lock
  */
-static int cpdma_chan_split_pool(struct cpdma_ctlr *ctlr)
+int cpdma_chan_split_pool(struct cpdma_ctlr *ctlr)
 {
 	int tx_per_ch_desc = 0, rx_per_ch_desc = 0;
-	struct cpdma_desc_pool *pool = ctlr->pool;
 	int free_rx_num = 0, free_tx_num = 0;
 	int rx_weight = 0, tx_weight = 0;
 	int tx_desc_num, rx_desc_num;
 	struct cpdma_chan *chan;
-	int i, tx_num = 0;
+	int i;
 
 	if (!ctlr->chan_num)
 		return 0;
@@ -750,15 +755,14 @@ static int cpdma_chan_split_pool(struct cpdma_ctlr *ctlr)
 			if (!chan->weight)
 				free_tx_num++;
 			tx_weight += chan->weight;
-			tx_num++;
 		}
 	}
 
 	if (rx_weight > 100 || tx_weight > 100)
 		return -EINVAL;
 
-	tx_desc_num = (tx_num * pool->num_desc) / ctlr->chan_num;
-	rx_desc_num = pool->num_desc - tx_desc_num;
+	tx_desc_num = ctlr->num_tx_desc;
+	rx_desc_num = ctlr->num_rx_desc;
 
 	if (free_tx_num) {
 		tx_per_ch_desc = tx_desc_num - (tx_weight * tx_desc_num) / 100;
@@ -774,6 +778,8 @@ static int cpdma_chan_split_pool(struct cpdma_ctlr *ctlr)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(cpdma_chan_split_pool);
+
 
 /* cpdma_chan_set_weight - set weight of a channel in percentage.
  * Tx and Rx channels have separate weights. That is 100% for RX
@@ -907,7 +913,6 @@ struct cpdma_chan *cpdma_chan_create(struct cpdma_ctlr *ctlr, int chan_num,
 	chan->chan_num	= chan_num;
 	chan->handler	= handler;
 	chan->rate	= 0;
-	chan->desc_num = ctlr->pool->num_desc / 2;
 	chan->weight	= 0;
 
 	if (is_rx_chan(chan)) {
@@ -1329,4 +1334,23 @@ int cpdma_control_set(struct cpdma_ctlr *ctlr, int control, int value)
 }
 EXPORT_SYMBOL_GPL(cpdma_control_set);
 
+int cpdma_get_num_rx_descs(struct cpdma_ctlr *ctlr)
+{
+	return ctlr->num_rx_desc;
+}
+EXPORT_SYMBOL_GPL(cpdma_get_num_rx_descs);
+
+int cpdma_get_num_tx_descs(struct cpdma_ctlr *ctlr)
+{
+	return ctlr->num_tx_desc;
+}
+EXPORT_SYMBOL_GPL(cpdma_get_num_tx_descs);
+
+void cpdma_set_num_rx_descs(struct cpdma_ctlr *ctlr, int num_rx_desc)
+{
+	ctlr->num_rx_desc = num_rx_desc;
+	ctlr->num_tx_desc = ctlr->pool->num_desc - ctlr->num_rx_desc;
+}
+EXPORT_SYMBOL_GPL(cpdma_set_num_rx_descs);
+
 MODULE_LICENSE("GPL");
diff --git a/drivers/net/ethernet/ti/davinci_cpdma.h b/drivers/net/ethernet/ti/davinci_cpdma.h
index cb45f8f543d9..fd65ce2b83de 100644
--- a/drivers/net/ethernet/ti/davinci_cpdma.h
+++ b/drivers/net/ethernet/ti/davinci_cpdma.h
@@ -114,5 +114,9 @@ enum cpdma_control {
 
 int cpdma_control_get(struct cpdma_ctlr *ctlr, int control);
 int cpdma_control_set(struct cpdma_ctlr *ctlr, int control, int value);
+int cpdma_get_num_rx_descs(struct cpdma_ctlr *ctlr);
+void cpdma_set_num_rx_descs(struct cpdma_ctlr *ctlr, int num_rx_desc);
+int cpdma_get_num_tx_descs(struct cpdma_ctlr *ctlr);
+int cpdma_chan_split_pool(struct cpdma_ctlr *ctlr);
 
 #endif