net: mscc: ocelot: configure watermarks using devlink-sb

Using devlink-sb, we can configure 12/16 (the important 75%) of the
switch's controlling watermarks for congestion drops, and we can monitor
50% of the watermark occupancies (we can monitor the reservation
watermarks, but not the sharing watermarks, which are exposed as pool
sizes).

The following definitions can be made:

SB_BUF=0 # The devlink-sb for frame buffers
SB_REF=1 # The devlink-sb for frame references
POOL_ING=0 # The pool for ingress traffic. Both devlink-sb instances
           # have one of these.
POOL_EGR=1 # The pool for egress traffic. Both devlink-sb instances
           # have one of these.

Editing the hardware watermarks is done in the following way:
BUF_xxxx_I is accessed when sb=$SB_BUF and pool=$POOL_ING
REF_xxxx_I is accessed when sb=$SB_REF and pool=$POOL_ING
BUF_xxxx_E is accessed when sb=$SB_BUF and pool=$POOL_EGR
REF_xxxx_E is accessed when sb=$SB_REF and pool=$POOL_EGR

Configuring the sharing watermarks for COL_SHR(dp=0) is done implicitly
by modifying the corresponding pool size. By default, the pool size has
maximum size, so this can be skipped.

devlink sb pool set pci/0000:00:00.5 sb $SB_BUF pool $POOL_ING \
	size 129840 thtype static

Since by default there is no buffer reservation, the above command has
maxed out BUF_COL_SHR_I(dp=0).

Configuring the per-port reservation watermark (P_RSRV) is done in the
following way:

devlink sb port pool set pci/0000:00:00.5/0 sb $SB_BUF \
	pool $POOL_ING th 1000

The above command sets BUF_P_RSRV_I(port 0) to 1000 bytes. After this
command, the sharing watermarks are internally reconfigured with 1000
bytes less, i.e. from 129840 bytes to 128840 bytes.

Configuring the per-port-tc reservation watermarks (Q_RSRV) is done in
the following way:

for tc in {0..7}; do
	devlink sb tc bind set pci/0000:00:00.5/0 sb 0 tc $tc \
		type ingress pool $POOL_ING \
		th 3000
done

The above command sets BUF_Q_RSRV_I(port 0, tc 0..7) to 3000 bytes.
The sharing watermarks are again reconfigured with 24000 bytes less.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/dsa/ocelot/felix.c

@@ -427,6 +427,7 @@ static int felix_init_structs(struct felix *felix, int num_phys_ports)
 	ocelot->ops		= felix->info->ops;
 	ocelot->inj_prefix	= OCELOT_TAG_PREFIX_SHORT;
 	ocelot->xtr_prefix	= OCELOT_TAG_PREFIX_SHORT;
+	ocelot->devlink		= felix->ds->devlink;
 
 	port_phy_modes = kcalloc(num_phys_ports, sizeof(phy_interface_t),
 				 GFP_KERNEL);
@@ -588,6 +589,10 @@ static int felix_setup(struct dsa_switch *ds)
 		felix_port_qos_map_init(ocelot, port);
 	}
 
+	err = ocelot_devlink_sb_register(ocelot);
+	if (err)
+		return err;
+
 	/* Include the CPU port module in the forwarding mask for unknown
 	 * unicast - the hardware default value for ANA_FLOODING_FLD_UNICAST
 	 * excludes BIT(ocelot->num_phys_ports), and so does ocelot_init, since
@@ -609,6 +614,7 @@ static void felix_teardown(struct dsa_switch *ds)
 	struct felix *felix = ocelot_to_felix(ocelot);
 	int port;
 
+	ocelot_devlink_sb_unregister(ocelot);
 	ocelot_deinit_timestamp(ocelot);
 	ocelot_deinit(ocelot);
 
@@ -750,6 +756,108 @@ static int felix_port_setup_tc(struct dsa_switch *ds, int port,
 		return -EOPNOTSUPP;
 }
 
+static int felix_sb_pool_get(struct dsa_switch *ds, unsigned int sb_index,
+			     u16 pool_index,
+			     struct devlink_sb_pool_info *pool_info)
+{
+	struct ocelot *ocelot = ds->priv;
+
+	return ocelot_sb_pool_get(ocelot, sb_index, pool_index, pool_info);
+}
+
+static int felix_sb_pool_set(struct dsa_switch *ds, unsigned int sb_index,
+			     u16 pool_index, u32 size,
+			     enum devlink_sb_threshold_type threshold_type,
+			     struct netlink_ext_ack *extack)
+{
+	struct ocelot *ocelot = ds->priv;
+
+	return ocelot_sb_pool_set(ocelot, sb_index, pool_index, size,
+				  threshold_type, extack);
+}
+
+static int felix_sb_port_pool_get(struct dsa_switch *ds, int port,
+				  unsigned int sb_index, u16 pool_index,
+				  u32 *p_threshold)
+{
+	struct ocelot *ocelot = ds->priv;
+
+	return ocelot_sb_port_pool_get(ocelot, port, sb_index, pool_index,
+				       p_threshold);
+}
+
+static int felix_sb_port_pool_set(struct dsa_switch *ds, int port,
+				  unsigned int sb_index, u16 pool_index,
+				  u32 threshold, struct netlink_ext_ack *extack)
+{
+	struct ocelot *ocelot = ds->priv;
+
+	return ocelot_sb_port_pool_set(ocelot, port, sb_index, pool_index,
+				       threshold, extack);
+}
+
+static int felix_sb_tc_pool_bind_get(struct dsa_switch *ds, int port,
+				     unsigned int sb_index, u16 tc_index,
+				     enum devlink_sb_pool_type pool_type,
+				     u16 *p_pool_index, u32 *p_threshold)
+{
+	struct ocelot *ocelot = ds->priv;
+
+	return ocelot_sb_tc_pool_bind_get(ocelot, port, sb_index, tc_index,
+					  pool_type, p_pool_index,
+					  p_threshold);
+}
+
+static int felix_sb_tc_pool_bind_set(struct dsa_switch *ds, int port,
+				     unsigned int sb_index, u16 tc_index,
+				     enum devlink_sb_pool_type pool_type,
+				     u16 pool_index, u32 threshold,
+				     struct netlink_ext_ack *extack)
+{
+	struct ocelot *ocelot = ds->priv;
+
+	return ocelot_sb_tc_pool_bind_set(ocelot, port, sb_index, tc_index,
+					  pool_type, pool_index, threshold,
+					  extack);
+}
+
+static int felix_sb_occ_snapshot(struct dsa_switch *ds,
+				 unsigned int sb_index)
+{
+	struct ocelot *ocelot = ds->priv;
+
+	return ocelot_sb_occ_snapshot(ocelot, sb_index);
+}
+
+static int felix_sb_occ_max_clear(struct dsa_switch *ds,
+				  unsigned int sb_index)
+{
+	struct ocelot *ocelot = ds->priv;
+
+	return ocelot_sb_occ_max_clear(ocelot, sb_index);
+}
+
+static int felix_sb_occ_port_pool_get(struct dsa_switch *ds, int port,
+				      unsigned int sb_index, u16 pool_index,
+				      u32 *p_cur, u32 *p_max)
+{
+	struct ocelot *ocelot = ds->priv;
+
+	return ocelot_sb_occ_port_pool_get(ocelot, port, sb_index, pool_index,
+					   p_cur, p_max);
+}
+
+static int felix_sb_occ_tc_port_bind_get(struct dsa_switch *ds, int port,
+					 unsigned int sb_index, u16 tc_index,
+					 enum devlink_sb_pool_type pool_type,
+					 u32 *p_cur, u32 *p_max)
+{
+	struct ocelot *ocelot = ds->priv;
+
+	return ocelot_sb_occ_tc_port_bind_get(ocelot, port, sb_index, tc_index,
+					      pool_type, p_cur, p_max);
+}
+
 const struct dsa_switch_ops felix_switch_ops = {
 	.get_tag_protocol		= felix_get_tag_protocol,
 	.setup				= felix_setup,
@@ -788,6 +896,16 @@ const struct dsa_switch_ops felix_switch_ops = {
 	.cls_flower_del			= felix_cls_flower_del,
 	.cls_flower_stats		= felix_cls_flower_stats,
 	.port_setup_tc			= felix_port_setup_tc,
+	.devlink_sb_pool_get		= felix_sb_pool_get,
+	.devlink_sb_pool_set		= felix_sb_pool_set,
+	.devlink_sb_port_pool_get	= felix_sb_port_pool_get,
+	.devlink_sb_port_pool_set	= felix_sb_port_pool_set,
+	.devlink_sb_tc_pool_bind_get	= felix_sb_tc_pool_bind_get,
+	.devlink_sb_tc_pool_bind_set	= felix_sb_tc_pool_bind_set,
+	.devlink_sb_occ_snapshot	= felix_sb_occ_snapshot,
+	.devlink_sb_occ_max_clear	= felix_sb_occ_max_clear,
+	.devlink_sb_occ_port_pool_get	= felix_sb_occ_port_pool_get,
+	.devlink_sb_occ_tc_port_bind_get= felix_sb_occ_tc_port_bind_get,
 };
 
 struct net_device *felix_port_to_netdev(struct ocelot *ocelot, int port)

drivers/net/ethernet/mscc/ocelot.c

@@ -1480,10 +1480,6 @@ static void ocelot_detect_features(struct ocelot *ocelot)
 
 	eq_ctrl = ocelot_read(ocelot, QSYS_EQ_CTRL);
 	ocelot->num_frame_refs = QSYS_MMGT_EQ_CTRL_FP_FREE_CNT(eq_ctrl);
-
-	dev_info(ocelot->dev,
-		 "Detected %d bytes of packet buffer and %d frame references\n",
-		 ocelot->packet_buffer_size, ocelot->num_frame_refs);
 }
 
 int ocelot_init(struct ocelot *ocelot)
@@ -1624,7 +1620,6 @@ int ocelot_init(struct ocelot *ocelot)
 	INIT_DELAYED_WORK(&ocelot->stats_work, ocelot_check_stats_work);
 	queue_delayed_work(ocelot->stats_queue, &ocelot->stats_work,
 			   OCELOT_STATS_CHECK_DELAY);
-	ocelot_watermark_init(ocelot);
 
 	return 0;
 }

drivers/net/ethernet/mscc/ocelot.h

@@ -126,7 +126,6 @@ void ocelot_devlink_teardown(struct ocelot *ocelot);
 int ocelot_port_devlink_init(struct ocelot *ocelot, int port,
 			     enum devlink_port_flavour flavour);
 void ocelot_port_devlink_teardown(struct ocelot *ocelot, int port);
-void ocelot_watermark_init(struct ocelot *ocelot);
 
 extern struct notifier_block ocelot_netdevice_nb;
 extern struct notifier_block ocelot_switchdev_nb;

drivers/net/ethernet/mscc/ocelot_net.c

 // SPDX-License-Identifier: (GPL-2.0 OR MIT)
 /* Microsemi Ocelot Switch driver
+ *
+ * This contains glue logic between the switchdev driver operations and the
+ * mscc_ocelot_switch_lib.
  *
  * Copyright (c) 2017, 2019 Microsemi Corporation
+ * Copyright 2020-2021 NXP Semiconductors
  */
 
 #include <linux/if_bridge.h>
 #include "ocelot.h"
 #include "ocelot_vcap.h"
 
+static struct ocelot *devlink_port_to_ocelot(struct devlink_port *dlp)
+{
+	return devlink_priv(dlp->devlink);
+}
+
+static int devlink_port_to_port(struct devlink_port *dlp)
+{
+	struct ocelot *ocelot = devlink_port_to_ocelot(dlp);
+
+	return dlp - ocelot->devlink_ports;
+}
+
+static int ocelot_devlink_sb_pool_get(struct devlink *dl,
+				      unsigned int sb_index, u16 pool_index,
+				      struct devlink_sb_pool_info *pool_info)
+{
+	struct ocelot *ocelot = devlink_priv(dl);
+
+	return ocelot_sb_pool_get(ocelot, sb_index, pool_index, pool_info);
+}
+
+static int ocelot_devlink_sb_pool_set(struct devlink *dl, unsigned int sb_index,
+				      u16 pool_index, u32 size,
+				      enum devlink_sb_threshold_type threshold_type,
+				      struct netlink_ext_ack *extack)
+{
+	struct ocelot *ocelot = devlink_priv(dl);
+
+	return ocelot_sb_pool_set(ocelot, sb_index, pool_index, size,
+				  threshold_type, extack);
+}
+
+static int ocelot_devlink_sb_port_pool_get(struct devlink_port *dlp,
+					   unsigned int sb_index, u16 pool_index,
+					   u32 *p_threshold)
+{
+	struct ocelot *ocelot = devlink_port_to_ocelot(dlp);
+	int port = devlink_port_to_port(dlp);
+
+	return ocelot_sb_port_pool_get(ocelot, port, sb_index, pool_index,
+				       p_threshold);
+}
+
+static int ocelot_devlink_sb_port_pool_set(struct devlink_port *dlp,
+					   unsigned int sb_index, u16 pool_index,
+					   u32 threshold,
+					   struct netlink_ext_ack *extack)
+{
+	struct ocelot *ocelot = devlink_port_to_ocelot(dlp);
+	int port = devlink_port_to_port(dlp);
+
+	return ocelot_sb_port_pool_set(ocelot, port, sb_index, pool_index,
+				       threshold, extack);
+}
+
+static int
+ocelot_devlink_sb_tc_pool_bind_get(struct devlink_port *dlp,
+				   unsigned int sb_index, u16 tc_index,
+				   enum devlink_sb_pool_type pool_type,
+				   u16 *p_pool_index, u32 *p_threshold)
+{
+	struct ocelot *ocelot = devlink_port_to_ocelot(dlp);
+	int port = devlink_port_to_port(dlp);
+
+	return ocelot_sb_tc_pool_bind_get(ocelot, port, sb_index, tc_index,
+					  pool_type, p_pool_index,
+					  p_threshold);
+}
+
+static int
+ocelot_devlink_sb_tc_pool_bind_set(struct devlink_port *dlp,
+				   unsigned int sb_index, u16 tc_index,
+				   enum devlink_sb_pool_type pool_type,
+				   u16 pool_index, u32 threshold,
+				   struct netlink_ext_ack *extack)
+{
+	struct ocelot *ocelot = devlink_port_to_ocelot(dlp);
+	int port = devlink_port_to_port(dlp);
+
+	return ocelot_sb_tc_pool_bind_set(ocelot, port, sb_index, tc_index,
+					  pool_type, pool_index, threshold,
+					  extack);
+}
+
+static int ocelot_devlink_sb_occ_snapshot(struct devlink *dl,
+					  unsigned int sb_index)
+{
+	struct ocelot *ocelot = devlink_priv(dl);
+
+	return ocelot_sb_occ_snapshot(ocelot, sb_index);
+}
+
+static int ocelot_devlink_sb_occ_max_clear(struct devlink *dl,
+					   unsigned int sb_index)
+{
+	struct ocelot *ocelot = devlink_priv(dl);
+
+	return ocelot_sb_occ_max_clear(ocelot, sb_index);
+}
+
+static int ocelot_devlink_sb_occ_port_pool_get(struct devlink_port *dlp,
+					       unsigned int sb_index,
+					       u16 pool_index, u32 *p_cur,
+					       u32 *p_max)
+{
+	struct ocelot *ocelot = devlink_port_to_ocelot(dlp);
+	int port = devlink_port_to_port(dlp);
+
+	return ocelot_sb_occ_port_pool_get(ocelot, port, sb_index, pool_index,
+					   p_cur, p_max);
+}
+
+static int
+ocelot_devlink_sb_occ_tc_port_bind_get(struct devlink_port *dlp,
+				       unsigned int sb_index, u16 tc_index,
+				       enum devlink_sb_pool_type pool_type,
+				       u32 *p_cur, u32 *p_max)
+{
+	struct ocelot *ocelot = devlink_port_to_ocelot(dlp);
+	int port = devlink_port_to_port(dlp);
+
+	return ocelot_sb_occ_tc_port_bind_get(ocelot, port, sb_index,
+					      tc_index, pool_type,
+					      p_cur, p_max);
+}
+
 const struct devlink_ops ocelot_devlink_ops = {
+	.sb_pool_get			= ocelot_devlink_sb_pool_get,
+	.sb_pool_set			= ocelot_devlink_sb_pool_set,
+	.sb_port_pool_get		= ocelot_devlink_sb_port_pool_get,
+	.sb_port_pool_set		= ocelot_devlink_sb_port_pool_set,
+	.sb_tc_pool_bind_get		= ocelot_devlink_sb_tc_pool_bind_get,
+	.sb_tc_pool_bind_set		= ocelot_devlink_sb_tc_pool_bind_set,
+	.sb_occ_snapshot		= ocelot_devlink_sb_occ_snapshot,
+	.sb_occ_max_clear		= ocelot_devlink_sb_occ_max_clear,
+	.sb_occ_port_pool_get		= ocelot_devlink_sb_occ_port_pool_get,
+	.sb_occ_tc_port_bind_get	= ocelot_devlink_sb_occ_tc_port_bind_get,
 };
 
 int ocelot_port_devlink_init(struct ocelot *ocelot, int port,

drivers/net/ethernet/mscc/ocelot_vsc7514.c

@@ -1363,6 +1363,10 @@ static int mscc_ocelot_probe(struct platform_device *pdev)
 	if (err)
 		goto out_ocelot_devlink_unregister;
 
+	err = ocelot_devlink_sb_register(ocelot);
+	if (err)
+		goto out_ocelot_release_ports;
+
 	if (ocelot->ptp) {
 		err = ocelot_init_timestamp(ocelot, &ocelot_ptp_clock_info);
 		if (err) {
@@ -1382,6 +1386,9 @@ static int mscc_ocelot_probe(struct platform_device *pdev)
 
 	return 0;
 
+out_ocelot_release_ports:
+	mscc_ocelot_release_ports(ocelot);
+	mscc_ocelot_teardown_devlink_ports(ocelot);
 out_ocelot_devlink_unregister:
 	devlink_unregister(devlink);
 out_ocelot_deinit:
@@ -1398,6 +1405,7 @@ static int mscc_ocelot_remove(struct platform_device *pdev)
 	struct ocelot *ocelot = platform_get_drvdata(pdev);
 
 	ocelot_deinit_timestamp(ocelot);
+	ocelot_devlink_sb_unregister(ocelot);
 	mscc_ocelot_release_ports(ocelot);
 	mscc_ocelot_teardown_devlink_ports(ocelot);
 	devlink_unregister(ocelot->devlink);

include/soc/mscc/ocelot.h

@@ -579,6 +579,18 @@ struct ocelot_vlan {
 	u16 vid;
 };
 
+enum ocelot_sb {
+	OCELOT_SB_BUF,
+	OCELOT_SB_REF,
+	OCELOT_SB_NUM,
+};
+
+enum ocelot_sb_pool {
+	OCELOT_SB_POOL_ING,
+	OCELOT_SB_POOL_EGR,
+	OCELOT_SB_POOL_NUM,
+};
+
 struct ocelot_port {
 	struct ocelot			*ocelot;
 
@@ -612,6 +624,7 @@ struct ocelot {
 	const struct ocelot_stat_layout	*stats_layout;
 	unsigned int			num_stats;
 
+	u32				pool_size[OCELOT_SB_NUM][OCELOT_SB_POOL_NUM];
 	int				packet_buffer_size;
 	int				num_frame_refs;
 	int				num_mact_rows;
@@ -783,4 +796,38 @@ int ocelot_port_mdb_add(struct ocelot *ocelot, int port,
 int ocelot_port_mdb_del(struct ocelot *ocelot, int port,
 			const struct switchdev_obj_port_mdb *mdb);
 
+int ocelot_devlink_sb_register(struct ocelot *ocelot);
+void ocelot_devlink_sb_unregister(struct ocelot *ocelot);
+int ocelot_sb_pool_get(struct ocelot *ocelot, unsigned int sb_index,
+		       u16 pool_index,
+		       struct devlink_sb_pool_info *pool_info);
+int ocelot_sb_pool_set(struct ocelot *ocelot, unsigned int sb_index,
+		       u16 pool_index, u32 size,
+		       enum devlink_sb_threshold_type threshold_type,
+		       struct netlink_ext_ack *extack);
+int ocelot_sb_port_pool_get(struct ocelot *ocelot, int port,
+			    unsigned int sb_index, u16 pool_index,
+			    u32 *p_threshold);
+int ocelot_sb_port_pool_set(struct ocelot *ocelot, int port,
+			    unsigned int sb_index, u16 pool_index,
+			    u32 threshold, struct netlink_ext_ack *extack);
+int ocelot_sb_tc_pool_bind_get(struct ocelot *ocelot, int port,
+			       unsigned int sb_index, u16 tc_index,
+			       enum devlink_sb_pool_type pool_type,
+			       u16 *p_pool_index, u32 *p_threshold);
+int ocelot_sb_tc_pool_bind_set(struct ocelot *ocelot, int port,
+			       unsigned int sb_index, u16 tc_index,
+			       enum devlink_sb_pool_type pool_type,
+			       u16 pool_index, u32 threshold,
+			       struct netlink_ext_ack *extack);
+int ocelot_sb_occ_snapshot(struct ocelot *ocelot, unsigned int sb_index);
+int ocelot_sb_occ_max_clear(struct ocelot *ocelot, unsigned int sb_index);
+int ocelot_sb_occ_port_pool_get(struct ocelot *ocelot, int port,
+				unsigned int sb_index, u16 pool_index,
+				u32 *p_cur, u32 *p_max);
+int ocelot_sb_occ_tc_port_bind_get(struct ocelot *ocelot, int port,
+				   unsigned int sb_index, u16 tc_index,
+				   enum devlink_sb_pool_type pool_type,
+				   u32 *p_cur, u32 *p_max);
+
 #endif