[RFC net-next 4/4] net: dsa: yt921x: Add port qdisc tbf support

[David Yang <mmyangfl@gmail.com>]

Enable port shaping and support limiting the rate of outgoing traffic.

Signed-off-by: David Yang <mmyangfl@gmail.com>
---
 drivers/net/dsa/yt921x.c | 113 +++++++++++++++++++++++++++++++++++++++
 drivers/net/dsa/yt921x.h |  18 +++++++
 2 files changed, 131 insertions(+)

diff --git a/drivers/net/dsa/yt921x.c b/drivers/net/dsa/yt921x.c
index f1465c4d9b1b..dd279f1db837 100644
--- a/drivers/net/dsa/yt921x.c
+++ b/drivers/net/dsa/yt921x.c
@@ -24,6 +24,7 @@
 #include <net/dsa.h>
 #include <net/dscp.h>
 #include <net/ieee8021q.h>
+#include <net/pkt_cls.h>
 
 #include "yt921x.h"
 
@@ -1291,6 +1292,110 @@ yt921x_dsa_port_policer_add(struct dsa_switch *ds, int port,
 	return res;
 }
 
+static int
+yt921x_tbf_validate(struct yt921x_priv *priv,
+		    const struct tc_tbf_qopt_offload *qopt, int *queuep)
+{
+	struct device *dev = to_device(priv);
+	int queue = -1;
+
+	if (qopt->parent != TC_H_ROOT) {
+		dev_err(dev, "Parent should be \"root\"\n");
+		return -EOPNOTSUPP;
+	}
+
+	switch (qopt->command) {
+	case TC_TBF_REPLACE: {
+		const struct tc_tbf_qopt_offload_replace_params *p;
+
+		p = &qopt->replace_params;
+
+		if (!p->rate.mpu) {
+			dev_info(dev, "Assuming you want mpu = 64\n");
+		} else if (p->rate.mpu != 64) {
+			dev_err(dev, "mpu other than 64 not supported\n");
+			return -EINVAL;
+		}
+	}
+	default:
+		break;
+	}
+
+	*queuep = queue;
+	return 0;
+}
+
+static int
+yt921x_dsa_port_setup_tc_tbf_port(struct dsa_switch *ds, int port,
+				  const struct tc_tbf_qopt_offload *qopt)
+{
+	struct yt921x_priv *priv = to_yt921x_priv(ds);
+	u32 ctrls[YT921X_PORT_SHAPE_CTRL_S];
+	int res;
+
+	switch (qopt->command) {
+	case TC_TBF_DESTROY:
+		ctrls[0] = 0;
+		ctrls[1] = 0;
+		break;
+	case TC_TBF_REPLACE: {
+		const struct tc_tbf_qopt_offload_replace_params *p;
+		struct yt921x_meter meter;
+		u64 burst;
+
+		p = &qopt->replace_params;
+
+		/* where is burst??? */
+		burst = priv->port_shape_slot_ns * p->rate.rate_bytes_ps /
+			1000000000 + 10000;
+		meter = yt921x_meter_tfm(priv, port, priv->port_shape_slot_ns,
+					 p->rate.rate_bytes_ps, burst,
+					 YT921X_METER_SINGLE_BUCKET,
+					 YT921X_SHAPE_RATE_MAX,
+					 YT921X_SHAPE_BURST_MAX,
+					 YT921X_SHAPE_UNIT_MAX);
+
+		ctrls[0] = YT921X_PORT_SHAPE_CTRLa_CIR(meter.cir) |
+			   YT921X_PORT_SHAPE_CTRLa_CBS(meter.cbs);
+		ctrls[1] = YT921X_PORT_SHAPE_CTRLb_UNIT(meter.unit) |
+			   YT921X_PORT_SHAPE_CTRLb_EN;
+		break;
+	}
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	mutex_lock(&priv->reg_lock);
+	res = yt921x_longreg_write(priv, YT921X_PORTn_SHAPE_CTRL(port),
+				   ctrls, YT921X_PORT_SHAPE_CTRL_S);
+	mutex_unlock(&priv->reg_lock);
+
+	return res;
+}
+
+static int
+yt921x_dsa_port_setup_tc(struct dsa_switch *ds, int port,
+			 enum tc_setup_type type, void *type_data)
+{
+	struct yt921x_priv *priv = to_yt921x_priv(ds);
+	int res;
+
+	switch (type) {
+	case TC_SETUP_QDISC_TBF: {
+		const struct tc_tbf_qopt_offload *qopt = type_data;
+		int queue;
+
+		res = yt921x_tbf_validate(priv, qopt, &queue);
+		if (res)
+			return res;
+
+		return yt921x_dsa_port_setup_tc_tbf_port(ds, port, qopt);
+	}
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
 static int
 yt921x_mirror_del(struct yt921x_priv *priv, int port, bool ingress)
 {
@@ -3445,6 +3550,13 @@ static int yt921x_chip_setup_tc(struct yt921x_priv *priv)
 		return res;
 	priv->meter_slot_ns = ctrl * op_ns;
 
+	ctrl = max(priv->port_shape_slot_ns / op_ns,
+		   YT921X_PORT_SHAPE_SLOT_MIN);
+	res = yt921x_reg_write(priv, YT921X_PORT_SHAPE_SLOT, ctrl);
+	if (res)
+		return res;
+	priv->port_shape_slot_ns = ctrl * op_ns;
+
 	return 0;
 }
 
@@ -3601,6 +3713,7 @@ static const struct dsa_switch_ops yt921x_dsa_switch_ops = {
 	/* rate */
 	.port_policer_del	= yt921x_dsa_port_policer_del,
 	.port_policer_add	= yt921x_dsa_port_policer_add,
+	.port_setup_tc		= yt921x_dsa_port_setup_tc,
 	/* hsr */
 	.port_hsr_leave		= dsa_port_simple_hsr_leave,
 	.port_hsr_join		= dsa_port_simple_hsr_join,
diff --git a/drivers/net/dsa/yt921x.h b/drivers/net/dsa/yt921x.h
index 129073ed3a4b..dbcd89c7bd6c 100644
--- a/drivers/net/dsa/yt921x.h
+++ b/drivers/net/dsa/yt921x.h
@@ -537,6 +537,19 @@ enum yt921x_app_selector {
 #define  YT921X_MIRROR_PORT_M			GENMASK(3, 0)
 #define   YT921X_MIRROR_PORT(x)				FIELD_PREP(YT921X_MIRROR_PORT_M, (x))
 
+#define YT921X_PORT_SHAPE_SLOT		0x34000c
+#define  YT921X_PORT_SHAPE_SLOT_SLOT_M		GENMASK(11, 0)
+#define YT921X_PORTn_SHAPE_CTRL(port)	(0x354000 + 8 * (port))
+#define  YT921X_PORT_SHAPE_CTRL_S		2
+#define  YT921X_PORT_SHAPE_CTRLb_EN		BIT(4)
+#define  YT921X_PORT_SHAPE_CTRLb_PKT_MODE	BIT(3)	/* 0: byte rate mode */
+#define  YT921X_PORT_SHAPE_CTRLb_UNIT_M		GENMASK(2, 0)
+#define   YT921X_PORT_SHAPE_CTRLb_UNIT(x)		FIELD_PREP(YT921X_PORT_SHAPE_CTRLb_UNIT_M, (x))
+#define  YT921X_PORT_SHAPE_CTRLa_CBS_M		GENMASK(31, 18)
+#define   YT921X_PORT_SHAPE_CTRLa_CBS(x)		FIELD_PREP(YT921X_PORT_SHAPE_CTRLa_CBS_M, (x))
+#define  YT921X_PORT_SHAPE_CTRLa_CIR_M		GENMASK(17, 0)
+#define   YT921X_PORT_SHAPE_CTRLa_CIR(x)		FIELD_PREP(YT921X_PORT_SHAPE_CTRLa_CIR_M, (x))
+
 #define YT921X_EDATA_EXTMODE	0xfb
 #define YT921X_EDATA_LEN	0x100
 
@@ -562,6 +575,10 @@ enum yt921x_fdb_entry_status {
 #define YT921X_METER_UNIT_MAX	((1 << 3) - 1)
 #define YT921X_METER_BURST_MAX	((1 << 16) - 1)
 #define YT921X_METER_RATE_MAX	((1 << 18) - 1)
+#define YT921X_PORT_SHAPE_SLOT_MIN	80
+#define YT921X_SHAPE_UNIT_MAX	((1 << 3) - 1)
+#define YT921X_SHAPE_BURST_MAX	((1 << 14) - 1)
+#define YT921X_SHAPE_RATE_MAX	((1 << 18) - 1)
 
 #define YT921X_LAG_NUM		2
 #define YT921X_LAG_PORT_NUM	4
@@ -658,6 +675,7 @@ struct yt921x_priv {
 
 	const struct yt921x_info *info;
 	unsigned int meter_slot_ns;
+	unsigned int port_shape_slot_ns;
 	/* cache of dsa_cpu_ports(ds) */
 	u16 cpu_ports_mask;
 	u8 cycle_ns;
-- 
2.51.0