net: mscc: ocelot: Implement port policers via tc command

Hardware offload of matchall classifier and police action are now
supported via the tc command.
Supported police parameters are: rate and burst.

Example:

Add:
tc qdisc add dev eth3 handle ffff: ingress
tc filter add dev eth3 parent ffff: prio 1 handle 2	\
	matchall skip_sw				\
	action police rate 100Mbit burst 10000

Show:
tc -s -d qdisc show dev eth3
tc -s -d filter show dev eth3 ingress

Delete:
tc filter del dev eth3 parent ffff: prio 1
tc qdisc del dev eth3 handle ffff: ingress

Signed-off-by: Joergen Andreasen <joergen.andreasen@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mscc/Makefile

@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: (GPL-2.0 OR MIT)
 obj-$(CONFIG_MSCC_OCELOT_SWITCH) += mscc_ocelot_common.o
 mscc_ocelot_common-y := ocelot.o ocelot_io.o
-mscc_ocelot_common-y += ocelot_regs.o
+mscc_ocelot_common-y += ocelot_regs.o ocelot_tc.o ocelot_police.o
 obj-$(CONFIG_MSCC_OCELOT_SWITCH_OCELOT) += ocelot_board.o

drivers/net/ethernet/mscc/ocelot.c

@@ -910,6 +910,13 @@ static int ocelot_set_features(struct net_device *dev,
 	struct ocelot_port *port = netdev_priv(dev);
 	netdev_features_t changed = dev->features ^ features;
 
+	if ((dev->features & NETIF_F_HW_TC) > (features & NETIF_F_HW_TC) &&
+	    port->tc.offload_cnt) {
+		netdev_err(dev,
+			   "Cannot disable HW TC offload while offloads active\n");
+		return -EBUSY;
+	}
+
 	if (changed & NETIF_F_HW_VLAN_CTAG_FILTER)
 		ocelot_vlan_mode(port, features);
 
@@ -943,6 +950,7 @@ static const struct net_device_ops ocelot_port_netdev_ops = {
 	.ndo_vlan_rx_kill_vid		= ocelot_vlan_rx_kill_vid,
 	.ndo_set_features		= ocelot_set_features,
 	.ndo_get_port_parent_id		= ocelot_get_port_parent_id,
+	.ndo_setup_tc			= ocelot_setup_tc,
 };
 
 static void ocelot_get_strings(struct net_device *netdev, u32 sset, u8 *data)
@@ -1663,8 +1671,9 @@ int ocelot_probe_port(struct ocelot *ocelot, u8 port,
 	dev->netdev_ops = &ocelot_port_netdev_ops;
 	dev->ethtool_ops = &ocelot_ethtool_ops;
 
-	dev->hw_features |= NETIF_F_HW_VLAN_CTAG_FILTER | NETIF_F_RXFCS;
-	dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
+	dev->hw_features |= NETIF_F_HW_VLAN_CTAG_FILTER | NETIF_F_RXFCS |
+		NETIF_F_HW_TC;
+	dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER | NETIF_F_HW_TC;
 
 	memcpy(dev->dev_addr, ocelot->base_mac, ETH_ALEN);
 	dev->dev_addr[ETH_ALEN - 1] += port;

drivers/net/ethernet/mscc/ocelot.h

@@ -22,6 +22,7 @@
 #include "ocelot_rew.h"
 #include "ocelot_sys.h"
 #include "ocelot_qs.h"
+#include "ocelot_tc.h"
 
 #define PGID_AGGR    64
 #define PGID_SRC     80
@@ -458,6 +459,8 @@ struct ocelot_port {
 
 	phy_interface_t phy_mode;
 	struct phy *serdes;
+
+	struct ocelot_port_tc tc;
 };
 
 u32 __ocelot_read_ix(struct ocelot *ocelot, u32 reg, u32 offset);

drivers/net/ethernet/mscc/ocelot_police.c

@@ -0,0 +1,227 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/* Microsemi Ocelot Switch driver
+ *
+ * Copyright (c) 2019 Microsemi Corporation
+ */
+
+#include "ocelot_police.h"
+
+enum mscc_qos_rate_mode {
+	MSCC_QOS_RATE_MODE_DISABLED, /* Policer/shaper disabled */
+	MSCC_QOS_RATE_MODE_LINE, /* Measure line rate in kbps incl. IPG */
+	MSCC_QOS_RATE_MODE_DATA, /* Measures data rate in kbps excl. IPG */
+	MSCC_QOS_RATE_MODE_FRAME, /* Measures frame rate in fps */
+	__MSCC_QOS_RATE_MODE_END,
+	NUM_MSCC_QOS_RATE_MODE = __MSCC_QOS_RATE_MODE_END,
+	MSCC_QOS_RATE_MODE_MAX = __MSCC_QOS_RATE_MODE_END - 1,
+};
+
+/* Types for ANA:POL[0-192]:POL_MODE_CFG.FRM_MODE */
+#define POL_MODE_LINERATE   0 /* Incl IPG. Unit: 33 1/3 kbps, 4096 bytes */
+#define POL_MODE_DATARATE   1 /* Excl IPG. Unit: 33 1/3 kbps, 4096 bytes  */
+#define POL_MODE_FRMRATE_HI 2 /* Unit: 33 1/3 fps, 32.8 frames */
+#define POL_MODE_FRMRATE_LO 3 /* Unit: 1/3 fps, 0.3 frames */
+
+/* Policer indexes */
+#define POL_IX_PORT    0    /* 0-11    : Port policers */
+#define POL_IX_QUEUE   32   /* 32-127  : Queue policers  */
+
+/* Default policer order */
+#define POL_ORDER 0x1d3 /* Ocelot policer order: Serial (QoS -> Port -> VCAP) */
+
+struct qos_policer_conf {
+	enum mscc_qos_rate_mode mode;
+	bool dlb; /* Enable DLB (dual leaky bucket mode */
+	bool cf;  /* Coupling flag (ignored in SLB mode) */
+	u32  cir; /* CIR in kbps/fps (ignored in SLB mode) */
+	u32  cbs; /* CBS in bytes/frames (ignored in SLB mode) */
+	u32  pir; /* PIR in kbps/fps */
+	u32  pbs; /* PBS in bytes/frames */
+	u8   ipg; /* Size of IPG when MSCC_QOS_RATE_MODE_LINE is chosen */
+};
+
+static int qos_policer_conf_set(struct ocelot_port *port, u32 pol_ix,
+				struct qos_policer_conf *conf)
+{
+	u32 cf = 0, cir_ena = 0, frm_mode = POL_MODE_LINERATE;
+	u32 cir = 0, cbs = 0, pir = 0, pbs = 0;
+	bool cir_discard = 0, pir_discard = 0;
+	struct ocelot *ocelot = port->ocelot;
+	u32 pbs_max = 0, cbs_max = 0;
+	u8 ipg = 20;
+	u32 value;
+
+	pir = conf->pir;
+	pbs = conf->pbs;
+
+	switch (conf->mode) {
+	case MSCC_QOS_RATE_MODE_LINE:
+	case MSCC_QOS_RATE_MODE_DATA:
+		if (conf->mode == MSCC_QOS_RATE_MODE_LINE) {
+			frm_mode = POL_MODE_LINERATE;
+			ipg = min_t(u8, GENMASK(4, 0), conf->ipg);
+		} else {
+			frm_mode = POL_MODE_DATARATE;
+		}
+		if (conf->dlb) {
+			cir_ena = 1;
+			cir = conf->cir;
+			cbs = conf->cbs;
+			if (cir == 0 && cbs == 0) {
+				/* Discard cir frames */
+				cir_discard = 1;
+			} else {
+				cir = DIV_ROUND_UP(cir, 100);
+				cir *= 3; /* 33 1/3 kbps */
+				cbs = DIV_ROUND_UP(cbs, 4096);
+				cbs = (cbs ? cbs : 1); /* No zero burst size */
+				cbs_max = 60; /* Limit burst size */
+				cf = conf->cf;
+				if (cf)
+					pir += conf->cir;
+			}
+		}
+		if (pir == 0 && pbs == 0) {
+			/* Discard PIR frames */
+			pir_discard = 1;
+		} else {
+			pir = DIV_ROUND_UP(pir, 100);
+			pir *= 3;  /* 33 1/3 kbps */
+			pbs = DIV_ROUND_UP(pbs, 4096);
+			pbs = (pbs ? pbs : 1); /* No zero burst size */
+			pbs_max = 60; /* Limit burst size */
+		}
+		break;
+	case MSCC_QOS_RATE_MODE_FRAME:
+		if (pir >= 100) {
+			frm_mode = POL_MODE_FRMRATE_HI;
+			pir = DIV_ROUND_UP(pir, 100);
+			pir *= 3;  /* 33 1/3 fps */
+			pbs = (pbs * 10) / 328; /* 32.8 frames */
+			pbs = (pbs ? pbs : 1); /* No zero burst size */
+			pbs_max = GENMASK(6, 0); /* Limit burst size */
+		} else {
+			frm_mode = POL_MODE_FRMRATE_LO;
+			if (pir == 0 && pbs == 0) {
+				/* Discard all frames */
+				pir_discard = 1;
+				cir_discard = 1;
+			} else {
+				pir *= 3; /* 1/3 fps */
+				pbs = (pbs * 10) / 3; /* 0.3 frames */
+				pbs = (pbs ? pbs : 1); /* No zero burst size */
+				pbs_max = 61; /* Limit burst size */
+			}
+		}
+		break;
+	default: /* MSCC_QOS_RATE_MODE_DISABLED */
+		/* Disable policer using maximum rate and zero burst */
+		pir = GENMASK(15, 0);
+		pbs = 0;
+		break;
+	}
+
+	/* Check limits */
+	if (pir > GENMASK(15, 0)) {
+		netdev_err(port->dev, "Invalid pir\n");
+		return -EINVAL;
+	}
+
+	if (cir > GENMASK(15, 0)) {
+		netdev_err(port->dev, "Invalid cir\n");
+		return -EINVAL;
+	}
+
+	if (pbs > pbs_max) {
+		netdev_err(port->dev, "Invalid pbs\n");
+		return -EINVAL;
+	}
+
+	if (cbs > cbs_max) {
+		netdev_err(port->dev, "Invalid cbs\n");
+		return -EINVAL;
+	}
+
+	value = (ANA_POL_MODE_CFG_IPG_SIZE(ipg) |
+		 ANA_POL_MODE_CFG_FRM_MODE(frm_mode) |
+		 (cf ? ANA_POL_MODE_CFG_DLB_COUPLED : 0) |
+		 (cir_ena ? ANA_POL_MODE_CFG_CIR_ENA : 0) |
+		 ANA_POL_MODE_CFG_OVERSHOOT_ENA);
+
+	ocelot_write_gix(ocelot, value, ANA_POL_MODE_CFG, pol_ix);
+
+	ocelot_write_gix(ocelot,
+			 ANA_POL_PIR_CFG_PIR_RATE(pir) |
+			 ANA_POL_PIR_CFG_PIR_BURST(pbs),
+			 ANA_POL_PIR_CFG, pol_ix);
+
+	ocelot_write_gix(ocelot,
+			 (pir_discard ? GENMASK(22, 0) : 0),
+			 ANA_POL_PIR_STATE, pol_ix);
+
+	ocelot_write_gix(ocelot,
+			 ANA_POL_CIR_CFG_CIR_RATE(cir) |
+			 ANA_POL_CIR_CFG_CIR_BURST(cbs),
+			 ANA_POL_CIR_CFG, pol_ix);
+
+	ocelot_write_gix(ocelot,
+			 (cir_discard ? GENMASK(22, 0) : 0),
+			 ANA_POL_CIR_STATE, pol_ix);
+
+	return 0;
+}
+
+int ocelot_port_policer_add(struct ocelot_port *port,
+			    struct ocelot_policer *pol)
+{
+	struct ocelot *ocelot = port->ocelot;
+	struct qos_policer_conf pp = { 0 };
+	int err;
+
+	if (!pol)
+		return -EINVAL;
+
+	pp.mode = MSCC_QOS_RATE_MODE_DATA;
+	pp.pir = pol->rate;
+	pp.pbs = pol->burst;
+
+	netdev_dbg(port->dev,
+		   "%s: port %u pir %u kbps, pbs %u bytes\n",
+		   __func__, port->chip_port, pp.pir, pp.pbs);
+
+	err = qos_policer_conf_set(port, POL_IX_PORT + port->chip_port, &pp);
+	if (err)
+		return err;
+
+	ocelot_rmw_gix(ocelot,
+		       ANA_PORT_POL_CFG_PORT_POL_ENA |
+		       ANA_PORT_POL_CFG_POL_ORDER(POL_ORDER),
+		       ANA_PORT_POL_CFG_PORT_POL_ENA |
+		       ANA_PORT_POL_CFG_POL_ORDER_M,
+		       ANA_PORT_POL_CFG, port->chip_port);
+
+	return 0;
+}
+
+int ocelot_port_policer_del(struct ocelot_port *port)
+{
+	struct ocelot *ocelot = port->ocelot;
+	struct qos_policer_conf pp = { 0 };
+	int err;
+
+	netdev_dbg(port->dev, "%s: port %u\n", __func__, port->chip_port);
+
+	pp.mode = MSCC_QOS_RATE_MODE_DISABLED;
+
+	err = qos_policer_conf_set(port, POL_IX_PORT + port->chip_port, &pp);
+	if (err)
+		return err;
+
+	ocelot_rmw_gix(ocelot,
+		       ANA_PORT_POL_CFG_POL_ORDER(POL_ORDER),
+		       ANA_PORT_POL_CFG_PORT_POL_ENA |
+		       ANA_PORT_POL_CFG_POL_ORDER_M,
+		       ANA_PORT_POL_CFG, port->chip_port);
+
+	return 0;
+}

drivers/net/ethernet/mscc/ocelot_police.h

@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR MIT) */
+/* Microsemi Ocelot Switch driver
+ *
+ * Copyright (c) 2019 Microsemi Corporation
+ */
+
+#ifndef _MSCC_OCELOT_POLICE_H_
+#define _MSCC_OCELOT_POLICE_H_
+
+#include "ocelot.h"
+
+struct ocelot_policer {
+	u32 rate; /* kilobit per second */
+	u32 burst; /* bytes */
+};
+
+int ocelot_port_policer_add(struct ocelot_port *port,
+			    struct ocelot_policer *pol);
+
+int ocelot_port_policer_del(struct ocelot_port *port);
+
+#endif /* _MSCC_OCELOT_POLICE_H_ */