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>

1 files changed, 118 insertions, 0 deletions

diff --git a/drivers/net/dsa/ocelot/felix.c b/drivers/net/dsa/ocelot/felix.c
index 0c6a7de03331..767cbdccdb3e 100644
--- a/drivers/net/dsa/ocelot/felix.c
+++ b/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)