Merge branch 'dpaa2-eth-add-PFC-support'

Ioana Ciornei says:

====================
dpaa2-eth: add PFC support

This patch set adds support for Priority Flow Control in DPAA2 Ethernet
devices.

The first patch make the necessary changes so that multiple
traffic classes are configured. The dequeue priority
of the maximum 8 traffic classes is configured to be equal.
The second patch adds a static distribution to said traffic
classes based on the VLAN PCP field. In the future, this could be
extended through the .setapp() DCB callback for dynamic configuration.

Also, add support for the congestion group taildrop mechanism that
allows us to control the number of frames that can accumulate on a group
of Rx frame queues belonging to the same traffic class.

The basic subset of the DCB ops is implemented so that the user can
query the number of PFC capable traffic classes, their state and
reconfigure them if necessary.

Changes in v3:
 - add patches 6-7 which add the PFC functionality
 - patch 2/7: revert to explicitly cast mask to u16 * to not get into
   sparse warnings
Changes in v4:
 - really fix the sparse warnings in 2/7
====================

Signed-off-by: David S. Miller <[email protected]>

Author: davem330

drivers/net/ethernet/freescale/dpaa2/Kconfig

@@ -9,6 +9,16 @@ config FSL_DPAA2_ETH
 	  The driver manages network objects discovered on the Freescale
 	  MC bus.
 
+if FSL_DPAA2_ETH
+config FSL_DPAA2_ETH_DCB
+	bool "Data Center Bridging (DCB) Support"
+	default n
+	depends on DCB
+	help
+	  Enable Priority-Based Flow Control (PFC) support for DPAA2 Ethernet
+	  devices.
+endif
+
 config FSL_DPAA2_PTP_CLOCK
 	tristate "Freescale DPAA2 PTP Clock"
 	depends on FSL_DPAA2_ETH && PTP_1588_CLOCK_QORIQ

drivers/net/ethernet/freescale/dpaa2/Makefile

@@ -7,6 +7,7 @@ obj-$(CONFIG_FSL_DPAA2_ETH)		+= fsl-dpaa2-eth.o
 obj-$(CONFIG_FSL_DPAA2_PTP_CLOCK)	+= fsl-dpaa2-ptp.o
 
 fsl-dpaa2-eth-objs	:= dpaa2-eth.o dpaa2-ethtool.o dpni.o dpaa2-mac.o dpmac.o
+fsl-dpaa2-eth-${CONFIG_FSL_DPAA2_ETH_DCB} += dpaa2-eth-dcb.o
 fsl-dpaa2-eth-${CONFIG_DEBUG_FS} += dpaa2-eth-debugfs.o
 fsl-dpaa2-ptp-objs	:= dpaa2-ptp.o dprtc.o
 

drivers/net/ethernet/freescale/dpaa2/dpaa2-eth-dcb.c

@@ -0,0 +1,150 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
+/* Copyright 2020 NXP */
+
+#include "dpaa2-eth.h"
+
+static int dpaa2_eth_dcbnl_ieee_getpfc(struct net_device *net_dev,
+				       struct ieee_pfc *pfc)
+{
+	struct dpaa2_eth_priv *priv = netdev_priv(net_dev);
+
+	if (!(priv->link_state.options & DPNI_LINK_OPT_PFC_PAUSE))
+		return 0;
+
+	memcpy(pfc, &priv->pfc, sizeof(priv->pfc));
+	pfc->pfc_cap = dpaa2_eth_tc_count(priv);
+
+	return 0;
+}
+
+static inline bool is_prio_enabled(u8 pfc_en, u8 tc)
+{
+	return !!(pfc_en & (1 << tc));
+}
+
+static int set_pfc_cn(struct dpaa2_eth_priv *priv, u8 pfc_en)
+{
+	struct dpni_congestion_notification_cfg cfg = {0};
+	int i, err;
+
+	cfg.notification_mode = DPNI_CONG_OPT_FLOW_CONTROL;
+	cfg.units = DPNI_CONGESTION_UNIT_FRAMES;
+	cfg.message_iova = 0ULL;
+	cfg.message_ctx = 0ULL;
+
+	for (i = 0; i < dpaa2_eth_tc_count(priv); i++) {
+		if (is_prio_enabled(pfc_en, i)) {
+			cfg.threshold_entry = DPAA2_ETH_CN_THRESH_ENTRY(priv);
+			cfg.threshold_exit = DPAA2_ETH_CN_THRESH_EXIT(priv);
+		} else {
+			/* For priorities not set in the pfc_en mask, we leave
+			 * the congestion thresholds at zero, which effectively
+			 * disables generation of PFC frames for them
+			 */
+			cfg.threshold_entry = 0;
+			cfg.threshold_exit = 0;
+		}
+
+		err = dpni_set_congestion_notification(priv->mc_io, 0,
+						       priv->mc_token,
+						       DPNI_QUEUE_RX, i, &cfg);
+		if (err) {
+			netdev_err(priv->net_dev,
+				   "dpni_set_congestion_notification failed\n");
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+static int dpaa2_eth_dcbnl_ieee_setpfc(struct net_device *net_dev,
+				       struct ieee_pfc *pfc)
+{
+	struct dpaa2_eth_priv *priv = netdev_priv(net_dev);
+	struct dpni_link_cfg link_cfg = {0};
+	bool tx_pause;
+	int err;
+
+	if (pfc->mbc || pfc->delay)
+		return -EOPNOTSUPP;
+
+	/* If same PFC enabled mask, nothing to do */
+	if (priv->pfc.pfc_en == pfc->pfc_en)
+		return 0;
+
+	/* We allow PFC configuration even if it won't have any effect until
+	 * general pause frames are enabled
+	 */
+	tx_pause = dpaa2_eth_tx_pause_enabled(priv->link_state.options);
+	if (!dpaa2_eth_rx_pause_enabled(priv->link_state.options) || !tx_pause)
+		netdev_warn(net_dev, "Pause support must be enabled in order for PFC to work!\n");
+
+	link_cfg.rate = priv->link_state.rate;
+	link_cfg.options = priv->link_state.options;
+	if (pfc->pfc_en)
+		link_cfg.options |= DPNI_LINK_OPT_PFC_PAUSE;
+	else
+		link_cfg.options &= ~DPNI_LINK_OPT_PFC_PAUSE;
+	err = dpni_set_link_cfg(priv->mc_io, 0, priv->mc_token, &link_cfg);
+	if (err) {
+		netdev_err(net_dev, "dpni_set_link_cfg failed\n");
+		return err;
+	}
+
+	/* Configure congestion notifications for the enabled priorities */
+	err = set_pfc_cn(priv, pfc->pfc_en);
+	if (err)
+		return err;
+
+	memcpy(&priv->pfc, pfc, sizeof(priv->pfc));
+	priv->pfc_enabled = !!pfc->pfc_en;
+
+	dpaa2_eth_set_rx_taildrop(priv, tx_pause, priv->pfc_enabled);
+
+	return 0;
+}
+
+static u8 dpaa2_eth_dcbnl_getdcbx(struct net_device *net_dev)
+{
+	struct dpaa2_eth_priv *priv = netdev_priv(net_dev);
+
+	return priv->dcbx_mode;
+}
+
+static u8 dpaa2_eth_dcbnl_setdcbx(struct net_device *net_dev, u8 mode)
+{
+	struct dpaa2_eth_priv *priv = netdev_priv(net_dev);
+
+	return (mode != (priv->dcbx_mode)) ? 1 : 0;
+}
+
+static u8 dpaa2_eth_dcbnl_getcap(struct net_device *net_dev, int capid, u8 *cap)
+{
+	struct dpaa2_eth_priv *priv = netdev_priv(net_dev);
+
+	switch (capid) {
+	case DCB_CAP_ATTR_PFC:
+		*cap = true;
+		break;
+	case DCB_CAP_ATTR_PFC_TCS:
+		*cap = 1 << (dpaa2_eth_tc_count(priv) - 1);
+		break;
+	case DCB_CAP_ATTR_DCBX:
+		*cap = priv->dcbx_mode;
+		break;
+	default:
+		*cap = false;
+		break;
+	}
+
+	return 0;
+}
+
+const struct dcbnl_rtnl_ops dpaa2_eth_dcbnl_ops = {
+	.ieee_getpfc	= dpaa2_eth_dcbnl_ieee_getpfc,
+	.ieee_setpfc	= dpaa2_eth_dcbnl_ieee_setpfc,
+	.getdcbx	= dpaa2_eth_dcbnl_getdcbx,
+	.setdcbx	= dpaa2_eth_dcbnl_setdcbx,
+	.getcap		= dpaa2_eth_dcbnl_getcap,
+};

drivers/net/ethernet/freescale/dpaa2/dpaa2-eth-debugfs.c

@@ -81,18 +81,19 @@ static int dpaa2_dbg_fqs_show(struct seq_file *file, void *offset)
 	int i, err;
 
 	seq_printf(file, "FQ stats for %s:\n", priv->net_dev->name);
-	seq_printf(file, "%s%16s%16s%16s%16s\n",
-		   "VFQID", "CPU", "Type", "Frames", "Pending frames");
+	seq_printf(file, "%s%16s%16s%16s%16s%16s\n",
+		   "VFQID", "CPU", "TC", "Type", "Frames", "Pending frames");
 
 	for (i = 0; i <  priv->num_fqs; i++) {
 		fq = &priv->fq[i];
 		err = dpaa2_io_query_fq_count(NULL, fq->fqid, &fcnt, &bcnt);
 		if (err)
 			fcnt = 0;
 
-		seq_printf(file, "%5d%16d%16s%16llu%16u\n",
+		seq_printf(file, "%5d%16d%16d%16s%16llu%16u\n",
 			   fq->fqid,
 			   fq->target_cpu,
+			   fq->tc,
 			   fq_type_to_str(fq),
 			   fq->stats.frames,
 			   fcnt);