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, 140 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mscc/ocelot_net.c b/drivers/net/ethernet/mscc/ocelot_net.c
index 4485faefc2b1..a520fd485912 100644
--- a/drivers/net/ethernet/mscc/ocelot_net.c
+++ b/drivers/net/ethernet/mscc/ocelot_net.c
@@ -1,14 +1,154 @@
 // 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,