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, 47 insertions, 0 deletions

diff --git a/include/soc/mscc/ocelot.h b/include/soc/mscc/ocelot.h
index fc7dc6679739..cdc33fa05660 100644
--- a/include/soc/mscc/ocelot.h
+++ b/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