dpaa2-eth: Add Tx shaping support

Add support in sysfs for controlling DPNI Tx shaping
parameters: rate limit (in Mbps) and max burst size (in bytes).
The settings are per port.

TODO: See how to integrate Tx shaping support using
standard Linux tools (ethtool)

Signed-off-by: Ioana Radulescu <ruxandra.radulescu@nxp.com>
Signed-off-by: Bogdan Purcareata <bogdan.purcareata@nxp.com>

2 files changed, 84 insertions, 0 deletions

diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
index becef56393bf..81c39fa41a32 100644
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
@@ -3771,6 +3771,83 @@ const struct dcbnl_rtnl_ops dpaa2_eth_dcbnl_ops = {
 };
 #endif
 
+/* SysFS support */
+static ssize_t dpaa2_eth_show_tx_shaping(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	struct dpaa2_eth_priv *priv = netdev_priv(to_net_dev(dev));
+	/* No MC API for getting the shaping config. We're stateful. */
+	struct dpni_tx_shaping_cfg *scfg = &priv->shaping_cfg;
+
+	return sprintf(buf, "%u %hu\n", scfg->rate_limit, scfg->max_burst_size);
+}
+
+static ssize_t dpaa2_eth_write_tx_shaping(struct device *dev,
+					  struct device_attribute *attr,
+					  const char *buf,
+					  size_t count)
+{
+	int err, items;
+	struct dpaa2_eth_priv *priv = netdev_priv(to_net_dev(dev));
+	struct dpni_tx_shaping_cfg scfg;
+
+	items = sscanf(buf, "%u %hu", &scfg.rate_limit, &scfg.max_burst_size);
+	if (items != 2) {
+		pr_err("Expected format: \"rate_limit(Mbps) max_burst_size(bytes)\"\n");
+		return -EINVAL;
+	}
+	/* Size restriction as per MC API documentation */
+	if (scfg.max_burst_size > DPAA2_ETH_MAX_BURST_SIZE) {
+		pr_err("max_burst_size must be <= %d\n",
+		       DPAA2_ETH_MAX_BURST_SIZE);
+		return -EINVAL;
+	}
+
+	err = dpni_set_tx_shaping(priv->mc_io, 0, priv->mc_token, &scfg);
+	if (err) {
+		dev_err(dev, "dpni_set_tx_shaping() failed\n");
+		return -EPERM;
+	}
+	/* If successful, save the current configuration for future inquiries */
+	priv->shaping_cfg = scfg;
+
+	return count;
+}
+
+static struct device_attribute dpaa2_eth_attrs[] = {
+	__ATTR(tx_shaping,
+	       0600,
+	       dpaa2_eth_show_tx_shaping,
+	       dpaa2_eth_write_tx_shaping),
+};
+
+static void dpaa2_eth_sysfs_init(struct device *dev)
+{
+	int i, err;
+
+	for (i = 0; i < ARRAY_SIZE(dpaa2_eth_attrs); i++) {
+		err = device_create_file(dev, &dpaa2_eth_attrs[i]);
+		if (err) {
+			dev_err(dev, "ERROR creating sysfs file\n");
+			goto undo;
+		}
+	}
+	return;
+
+undo:
+	while (i > 0)
+		device_remove_file(dev, &dpaa2_eth_attrs[--i]);
+}
+
+static void dpaa2_eth_sysfs_remove(struct device *dev)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(dpaa2_eth_attrs); i++)
+		device_remove_file(dev, &dpaa2_eth_attrs[i]);
+}
+
 static int dpaa2_eth_probe(struct fsl_mc_device *dpni_dev)
 {
 	struct device *dev;
@@ -3890,6 +3967,7 @@ static int dpaa2_eth_probe(struct fsl_mc_device *dpni_dev)
 #ifdef CONFIG_DEBUG_FS
 	dpaa2_dbg_add(priv);
 #endif
+	dpaa2_eth_sysfs_init(&net_dev->dev);
 
 	dev_info(dev, "Probed interface %s\n", net_dev->name);
 	return 0;
@@ -3937,6 +4015,8 @@ static int dpaa2_eth_remove(struct fsl_mc_device *ls_dev)
 #ifdef CONFIG_DEBUG_FS
 	dpaa2_dbg_remove(priv);
 #endif
+	dpaa2_eth_sysfs_remove(&net_dev->dev);
+
 	unregister_netdev(net_dev);
 
 	if (priv->do_link_poll)
diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h
index a0983463a0c0..1b67e32a3f3a 100644
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h
@@ -42,6 +42,9 @@
  */
 #define DPAA2_ETH_FQ_TAILDROP_THRESH	(1024 * 1024)
 
+/* Maximum burst size value for Tx shaping */
+#define DPAA2_ETH_MAX_BURST_SIZE	0xF7FF
+
 /* Maximum number of Tx confirmation frames to be processed
  * in a single NAPI call
  */
@@ -444,6 +447,7 @@ struct dpaa2_eth_priv {
 #ifdef CONFIG_DEBUG_FS
 	struct dpaa2_debugfs dbg;
 #endif
+	struct dpni_tx_shaping_cfg shaping_cfg;
 };
 
 #define DPAA2_RXH_SUPPORTED	(RXH_L2DA | RXH_VLAN | RXH_L3_PROTO \