[PATCH net-next v6 0/2] Add Frame Preemption MAC Merge support for ICSSG

[PATCH net-next v6 0/2] Add Frame Preemption MAC Merge support for ICSSG

[Meghana Malladi]

This patch series adds QoS support to the ICSSG PRUETH driver.
The first patch implements mqprio qdisc handling and TC offload hooks
so userspace can request TC mappings and queue counts.

It also integrates a driver-side mechanism to program the firmware
with the IET/FPE preemption mask and to kick the firmware verify state
machine when frame preemption is enabled. The second patch adds ethtool
perations for the MAC Merge (Frame Preemption) sublayer, exposing .get_mm,
.set_mm and .get_mm_stats so admins can view and change MAC Merge
parameters and retrieve preemption statistics.

v5: https://lore.kernel.org/all/20260430111723.497113-1-m-malladi@ti.com/

MD Danish Anwar (2):
  net: ti: icssg-prueth: Add Frame Preemption MAC Merge support
  net: ti: icssg-prueth: Add ethtool ops for Frame Preemption MAC Merge

 drivers/net/ethernet/ti/Makefile              |   3 +-
 drivers/net/ethernet/ti/icssg/icssg_common.c  |   1 +
 drivers/net/ethernet/ti/icssg/icssg_config.h  |   9 -
 drivers/net/ethernet/ti/icssg/icssg_ethtool.c | 106 +++++++
 drivers/net/ethernet/ti/icssg/icssg_prueth.c  |   6 +
 drivers/net/ethernet/ti/icssg/icssg_prueth.h  |   9 +-
 drivers/net/ethernet/ti/icssg/icssg_qos.c     | 269 ++++++++++++++++++
 drivers/net/ethernet/ti/icssg/icssg_qos.h     | 112 ++++++++
 drivers/net/ethernet/ti/icssg/icssg_stats.c   |   4 +-
 drivers/net/ethernet/ti/icssg/icssg_stats.h   |   7 +-
 .../net/ethernet/ti/icssg/icssg_switch_map.h  |   5 +
 11 files changed, 514 insertions(+), 17 deletions(-)
 create mode 100644 drivers/net/ethernet/ti/icssg/icssg_qos.c
 create mode 100644 drivers/net/ethernet/ti/icssg/icssg_qos.h


base-commit: 830d8771ae3c7bc90a62dde76a6556e612529fbc
-- 
2.43.0

[PATCH net-next v6 1/2] net: ti: icssg-prueth: Add Frame Preemption MAC Merge support

[Meghana Malladi]

From: MD Danish Anwar <danishanwar@ti.com>

Introduce QoS infrastructure for Frame Preemption (FPE) support in
the ICSSG Ethernet driver.

prueth_qos_iet tracks FPE enable/active state and verify state machine
status via firmware-reported enum icssg_ietfpe_verify_states.
icssg_config_ietfpe() configures IET FPE in firmware, triggers
verify state machine based on ethtool MAC Merge parameters.
Polls firmware verify status up to 3 times with verify_time_ms intervals
and driver handles timeout by logging error and returning.
In case of any failure during configuration for enable/disable,
IET FPE falls back to disabled state.

For MQPRIO qdisc support all queues are express by default later
gets override by user-provided preemptible_tcs bitmask via tc qdisc mask
Preempt mask configuration: Maps traffic classes to queue express/preemptible
state and applied only when FPE is active (Tx enabled)

Verify state machine re-triggers on link up/down events based on
fpe_enabled and fpe_active flags, and for memory protection, fpe_lock
serializes all FPE state mutations, preventing races between ethtool
config, qdisc setup, and link events

Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
Signed-off-by: Meghana Malladi <m-malladi@ti.com>
---

v6-v5:
- Balance fpe_lock mutex lifecycle on all error paths 
- Remove deadcode inside icssg_iet_set_preempt_mask()
- Add fallback label inside icssg_config_ietfpe() to fix
  stale state machine handling.
- Replace netdev_err with netdev_info and netdev_dbg wherever
  applicable
- Remove EXPORT_SYMBOL_GPL for icssg_config_ietfpe()
- Remove redundant code inside icssg_qos_init()
- qdisc deletion path clears per-queue map as well.
- Protect all read/writes to p_mqprio with a mutex
All the above changes address the comments raised by sashiko

 drivers/net/ethernet/ti/Makefile             |   3 +-
 drivers/net/ethernet/ti/icssg/icssg_common.c |   1 +
 drivers/net/ethernet/ti/icssg/icssg_config.h |   9 -
 drivers/net/ethernet/ti/icssg/icssg_prueth.c |   6 +
 drivers/net/ethernet/ti/icssg/icssg_prueth.h |   2 +
 drivers/net/ethernet/ti/icssg/icssg_qos.c    | 269 +++++++++++++++++++
 drivers/net/ethernet/ti/icssg/icssg_qos.h    |  66 +++++
 7 files changed, 346 insertions(+), 10 deletions(-)
 create mode 100644 drivers/net/ethernet/ti/icssg/icssg_qos.c
 create mode 100644 drivers/net/ethernet/ti/icssg/icssg_qos.h

diff --git a/drivers/net/ethernet/ti/Makefile b/drivers/net/ethernet/ti/Makefile
index f4276c9a77620..d19bcd25c9d07 100644
--- a/drivers/net/ethernet/ti/Makefile
+++ b/drivers/net/ethernet/ti/Makefile
@@ -46,6 +46,7 @@ icssg-y := icssg/icssg_common.o \
 	   icssg/icssg_config.o \
 	   icssg/icssg_mii_cfg.o \
 	   icssg/icssg_stats.o \
-	   icssg/icssg_ethtool.o
+	   icssg/icssg_ethtool.o \
+	   icssg/icssg_qos.o
 
 obj-$(CONFIG_TI_ICSS_IEP) += icssg/icss_iep.o
diff --git a/drivers/net/ethernet/ti/icssg/icssg_common.c b/drivers/net/ethernet/ti/icssg/icssg_common.c
index a28a608f9bf4b..c3ee97e96cd50 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_common.c
+++ b/drivers/net/ethernet/ti/icssg/icssg_common.c
@@ -1724,6 +1724,7 @@ void prueth_netdev_exit(struct prueth *prueth,
 
 	netif_napi_del(&emac->napi_rx);
 
+	mutex_destroy(&emac->qos.iet.fpe_lock);
 	pruss_release_mem_region(prueth->pruss, &emac->dram);
 	free_netdev(emac->ndev);
 	prueth->emac[mac] = NULL;
diff --git a/drivers/net/ethernet/ti/icssg/icssg_config.h b/drivers/net/ethernet/ti/icssg/icssg_config.h
index 60d69744ffae2..1ac202f855ed4 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_config.h
+++ b/drivers/net/ethernet/ti/icssg/icssg_config.h
@@ -323,13 +323,4 @@ struct prueth_fdb_slot {
 	u8 fid;
 	u8 fid_c2;
 } __packed;
-
-enum icssg_ietfpe_verify_states {
-	ICSSG_IETFPE_STATE_UNKNOWN = 0,
-	ICSSG_IETFPE_STATE_INITIAL,
-	ICSSG_IETFPE_STATE_VERIFYING,
-	ICSSG_IETFPE_STATE_SUCCEEDED,
-	ICSSG_IETFPE_STATE_FAILED,
-	ICSSG_IETFPE_STATE_DISABLED
-};
 #endif /* __NET_TI_ICSSG_CONFIG_H */
diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.c b/drivers/net/ethernet/ti/icssg/icssg_prueth.c
index 591be5c8056b4..39f379df923bf 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_prueth.c
+++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.c
@@ -392,6 +392,8 @@ static void emac_adjust_link(struct net_device *ndev)
 		} else {
 			icssg_set_port_state(emac, ICSSG_EMAC_PORT_DISABLE);
 		}
+
+		icssg_qos_link_state_update(ndev);
 	}
 
 	if (emac->link) {
@@ -1652,6 +1654,7 @@ static const struct net_device_ops emac_netdev_ops = {
 	.ndo_hwtstamp_get = icssg_ndo_get_ts_config,
 	.ndo_hwtstamp_set = icssg_ndo_set_ts_config,
 	.ndo_xsk_wakeup = prueth_xsk_wakeup,
+	.ndo_setup_tc = icssg_qos_ndo_setup_tc,
 };
 
 static int prueth_netdev_init(struct prueth *prueth,
@@ -1686,6 +1689,8 @@ static int prueth_netdev_init(struct prueth *prueth,
 
 	INIT_DELAYED_WORK(&emac->stats_work, icssg_stats_work_handler);
 
+	icssg_qos_init(ndev);
+
 	ret = pruss_request_mem_region(prueth->pruss,
 				       port == PRUETH_PORT_MII0 ?
 				       PRUSS_MEM_DRAM0 : PRUSS_MEM_DRAM1,
@@ -1793,6 +1798,7 @@ static int prueth_netdev_init(struct prueth *prueth,
 free:
 	pruss_release_mem_region(prueth->pruss, &emac->dram);
 free_ndev:
+	mutex_destroy(&emac->qos.iet.fpe_lock);
 	emac->ndev = NULL;
 	prueth->emac[mac] = NULL;
 	free_netdev(ndev);
diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.h b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
index df93d15c5b786..85f7017d2c8e7 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_prueth.h
+++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
@@ -44,6 +44,7 @@
 #include "icssg_config.h"
 #include "icss_iep.h"
 #include "icssg_switch_map.h"
+#include "icssg_qos.h"
 
 #define PRUETH_MAX_MTU          (2000 - ETH_HLEN - ETH_FCS_LEN)
 #define PRUETH_MIN_PKT_SIZE     (VLAN_ETH_ZLEN)
@@ -254,6 +255,7 @@ struct prueth_emac {
 	struct bpf_prog *xdp_prog;
 	struct xdp_attachment_info xdpi;
 	int xsk_qid;
+	struct prueth_qos qos;
 };
 
 /* The buf includes headroom compatible with both skb and xdpf */
diff --git a/drivers/net/ethernet/ti/icssg/icssg_qos.c b/drivers/net/ethernet/ti/icssg/icssg_qos.c
new file mode 100644
index 0000000000000..2781abf39e9bb
--- /dev/null
+++ b/drivers/net/ethernet/ti/icssg/icssg_qos.c
@@ -0,0 +1,269 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Texas Instruments ICSSG PRUETH QoS submodule
+ * Copyright (C) 2023 Texas Instruments Incorporated - http://www.ti.com/
+ */
+
+#include "icssg_prueth.h"
+#include "icssg_switch_map.h"
+
+static void icssg_iet_set_preempt_mask(struct prueth_emac *emac)
+{
+	void __iomem *config = emac->dram.va + ICSSG_CONFIG_OFFSET;
+	struct prueth_qos_mqprio *p_mqprio = &emac->qos.mqprio;
+	struct tc_mqprio_qopt *qopt = &p_mqprio->mqprio.qopt;
+	struct prueth_qos_iet *iet = &emac->qos.iet;
+	int prempt_mask = 0, i;
+	u8 tc, num_tc;
+
+	if (!iet->preemptible_tcs)
+		goto reset_hw;
+
+	if (iet->fpe_active) {
+		/* Configure the queues based on the preemptible tc map set by the user */
+		num_tc = p_mqprio->mqprio.qopt.num_tc;
+		for (tc = 0; tc < num_tc; tc++) {
+			/* check if the tc is preemptive or not */
+			if (iet->preemptible_tcs & BIT(tc)) {
+				for (i = qopt->offset[tc]; i < qopt->offset[tc] + qopt->count[tc]; i++) {
+					/* Set all the queues in this tc as preemptive queues */
+					writeb(BIT(4), config + EXPRESS_PRE_EMPTIVE_Q_MAP + i);
+				}
+			} else {
+				/* Set all the queues in this tc as express queues */
+				for (i = qopt->offset[tc]; i < qopt->offset[tc] + qopt->count[tc]; i++) {
+					writeb(0, config + EXPRESS_PRE_EMPTIVE_Q_MAP + i);
+					prempt_mask |= BIT(i);
+				}
+			}
+			netdev_set_tc_queue(emac->ndev, tc, qopt->count[tc], qopt->offset[tc]);
+		}
+		writeb(prempt_mask, config + EXPRESS_PRE_EMPTIVE_Q_MASK);
+		return;
+	}
+
+reset_hw:
+	/* Reset to default: all queues as express */
+	for (i = 0; i < ICSSG_MAX_TC_QUEUES; i++)
+		writeb(0, config + EXPRESS_PRE_EMPTIVE_Q_MAP + i);
+	writeb(ICSSG_EXPRESS_Q_MASK_ALL, config + EXPRESS_PRE_EMPTIVE_Q_MASK);
+}
+
+static int icssg_iet_verify_wait(struct prueth_emac *emac)
+{
+	void __iomem *config = emac->dram.va + ICSSG_CONFIG_OFFSET;
+	struct prueth_qos_iet *iet = &emac->qos.iet;
+	int try = 3;
+
+	do {
+		msleep(iet->verify_time_ms);
+		iet->verify_status = readb(config + PRE_EMPTION_VERIFY_STATUS);
+		if (iet->verify_status == ICSSG_IETFPE_STATE_SUCCEEDED)
+			return 0;
+	} while (--try > 0);
+
+	netdev_err(emac->ndev, "MAC Verify timeout\n");
+	return -ETIMEDOUT;
+}
+
+/* Direct synchronous configuration of IET FPE.
+ * Caller must hold iet->fpe_lock.
+ */
+int icssg_config_ietfpe(struct net_device *ndev, bool enable)
+{
+	struct prueth_emac *emac = netdev_priv(ndev);
+	void __iomem *config = emac->dram.va + ICSSG_CONFIG_OFFSET;
+	struct prueth_qos_iet *iet = &emac->qos.iet;
+	int ret;
+	u8 val;
+
+	lockdep_assert_held(&iet->fpe_lock);
+
+	if (!netif_running(ndev)) {
+		netdev_dbg(ndev, "cannot change IET/FPE state when interface is down\n");
+		return 0;
+	}
+
+	/* Update FPE Tx enable bit (PRE_EMPTION_ENABLE_TX) if
+	 * fpe_enabled is set to enable MM in Tx direction
+	 */
+	writeb(enable ? 1 : 0, config + PRE_EMPTION_ENABLE_TX);
+
+	/* If FPE is to be enabled, first configure MAC Verify state
+	 * machine in firmware as firmware kicks the Verify process
+	 * as soon as ICSSG_EMAC_PORT_PREMPT_TX_ENABLE command is
+	 * received.
+	 */
+	if (enable && iet->mac_verify_configure) {
+		writeb(1, config + PRE_EMPTION_ENABLE_VERIFY);
+		writew(iet->tx_min_frag_size + ETH_FCS_LEN,
+		       config + PRE_EMPTION_ADD_FRAG_SIZE_LOCAL);
+		writel(iet->verify_time_ms, config + PRE_EMPTION_VERIFY_TIME);
+	} else {
+		writeb(0, config + PRE_EMPTION_ENABLE_VERIFY);
+		iet->verify_status = ICSSG_IETFPE_STATE_DISABLED;
+	}
+
+	/* Send command to enable FPE Tx side. Rx is always enabled */
+	ret = icssg_set_port_state(emac,
+				   enable ? ICSSG_EMAC_PORT_PREMPT_TX_ENABLE :
+					    ICSSG_EMAC_PORT_PREMPT_TX_DISABLE);
+	if (ret) {
+		netdev_err(ndev, "TX preempt %s command failed\n",
+			   str_enable_disable(enable));
+		goto fallback;
+	}
+
+	if (enable && iet->mac_verify_configure) {
+		ret = icssg_iet_verify_wait(emac);
+		if (ret) {
+			netdev_err(ndev, "MAC Verification failed with timeout\n");
+			goto disable_tx;
+		}
+	} else if (enable) {
+		/* Give firmware some time to update PRE_EMPTION_ACTIVE_TX state */
+		usleep_range(100, 200);
+	}
+
+	if (enable) {
+		val = readb(config + PRE_EMPTION_ACTIVE_TX);
+		if (val != 1) {
+			netdev_err(ndev,
+				   "Firmware fails to activate IET/FPE\n");
+			ret = -EIO;
+			goto disable_tx;
+		}
+		iet->fpe_active = true;
+	} else {
+		iet->fpe_active = false;
+	}
+
+	icssg_iet_set_preempt_mask(emac);
+	netdev_info(ndev, "IET FPE %s successfully\n",
+		   str_enable_disable(iet->fpe_active));
+	return ret;
+
+disable_tx:
+	icssg_set_port_state(emac, ICSSG_EMAC_PORT_PREMPT_TX_DISABLE);
+fallback:
+	writeb(0, config + PRE_EMPTION_ENABLE_TX);
+	writeb(0, config + PRE_EMPTION_ENABLE_VERIFY);
+	iet->verify_status = ICSSG_IETFPE_STATE_DISABLED;
+	iet->fpe_active =  false;
+	return ret;
+}
+
+void icssg_qos_init(struct net_device *ndev)
+{
+	struct prueth_emac *emac = netdev_priv(ndev);
+	struct prueth_qos_iet *iet = &emac->qos.iet;
+
+	mutex_init(&iet->fpe_lock);
+	/* Set default values to prevent garbage values during .get_mm() */
+	mutex_lock(&iet->fpe_lock);
+	iet->verify_time_ms = ICSSG_IET_MAX_VERIFY_TIME;
+	iet->tx_min_frag_size = ETH_ZLEN;
+	mutex_unlock(&iet->fpe_lock);
+}
+EXPORT_SYMBOL_GPL(icssg_qos_init);
+
+static int icssg_iet_change_preemptible_tcs(struct prueth_emac *emac)
+{
+	struct prueth_qos_iet *iet = &emac->qos.iet;
+	int ret;
+
+	mutex_lock(&iet->fpe_lock);
+	ret = icssg_config_ietfpe(emac->ndev, iet->fpe_enabled);
+	mutex_unlock(&iet->fpe_lock);
+
+	return ret;
+}
+
+static int emac_tc_query_caps(struct net_device *ndev, void *type_data)
+{
+	struct tc_query_caps_base *base = type_data;
+
+	switch (base->type) {
+	case TC_SETUP_QDISC_MQPRIO: {
+		struct tc_mqprio_caps *caps = base->caps;
+
+		caps->validate_queue_counts = true;
+		return 0;
+	}
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int emac_tc_setup_mqprio(struct net_device *ndev, void *type_data)
+{
+	struct prueth_emac *emac = netdev_priv(ndev);
+	struct prueth_qos_mqprio *p_mqprio = &emac->qos.mqprio;
+	struct tc_mqprio_qopt_offload *mqprio = type_data;
+	struct prueth_qos_iet *iet = &emac->qos.iet;
+	int ret;
+
+	/* Validate parameters */
+	if (mqprio->qopt.num_tc > ICSSG_MAX_TC_QUEUES) {
+		netdev_err(ndev, "Number of traffic classes (%u) exceeds hardware limit\n",
+			   mqprio->qopt.num_tc);
+		return -EINVAL;
+	}
+
+	if (mqprio->flags & TC_MQPRIO_F_SHAPER) {
+		netdev_err(ndev, "traffic shaping is not supported\n");
+		return -EINVAL;
+	}
+
+	if (mqprio->flags & (TC_MQPRIO_F_MIN_RATE | TC_MQPRIO_F_MAX_RATE)) {
+		netdev_err(ndev, "per-queue rate limiting is not supported\n");
+		return -EINVAL;
+	}
+
+	if (!mqprio->qopt.num_tc) {
+		netdev_reset_tc(ndev);
+	} else {
+		netdev_set_num_tc(ndev, mqprio->qopt.num_tc);
+	}
+
+	mutex_lock(&iet->fpe_lock);
+	if (!mqprio->qopt.num_tc) {
+		iet->preemptible_tcs = 0;
+	} else {
+		memcpy(&p_mqprio->mqprio, mqprio, sizeof(*mqprio));
+		iet->preemptible_tcs = mqprio->preemptible_tcs;
+	}
+	mutex_unlock(&iet->fpe_lock);
+
+	netdev_dbg(ndev, "dev->num_tc %u dev->real_num_tx_queues %u\n",
+		   ndev->num_tc, ndev->real_num_tx_queues);
+
+	ret = icssg_iet_change_preemptible_tcs(emac);
+	return ret;
+}
+
+int icssg_qos_ndo_setup_tc(struct net_device *ndev, enum tc_setup_type type,
+			   void *type_data)
+{
+	switch (type) {
+	case TC_QUERY_CAPS:
+		return emac_tc_query_caps(ndev, type_data);
+	case TC_SETUP_QDISC_MQPRIO:
+		return emac_tc_setup_mqprio(ndev, type_data);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+EXPORT_SYMBOL_GPL(icssg_qos_ndo_setup_tc);
+
+void icssg_qos_link_state_update(struct net_device *ndev)
+{
+	struct prueth_emac *emac = netdev_priv(ndev);
+	struct prueth_qos_iet *iet = &emac->qos.iet;
+	int ret;
+
+	ret = icssg_iet_change_preemptible_tcs(emac);
+	if (ret)
+		netdev_dbg(ndev, "IET FPE %s failed\n",
+		   str_enable_disable(iet->fpe_active));
+}
+EXPORT_SYMBOL_GPL(icssg_qos_link_state_update);
diff --git a/drivers/net/ethernet/ti/icssg/icssg_qos.h b/drivers/net/ethernet/ti/icssg/icssg_qos.h
new file mode 100644
index 0000000000000..9355e96bbcda8
--- /dev/null
+++ b/drivers/net/ethernet/ti/icssg/icssg_qos.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2023 Texas Instruments Incorporated - http://www.ti.com/
+ */
+
+#ifndef __NET_TI_ICSSG_QOS_H
+#define __NET_TI_ICSSG_QOS_H
+
+#include <linux/atomic.h>
+#include <linux/netdevice.h>
+#include <net/pkt_sched.h>
+
+#define ICSSG_MAX_TC_QUEUES			8
+#define ICSSG_EXPRESS_Q_MASK_ALL		0xFF
+#define ICSSG_IET_MAX_VERIFY_TIME		128
+#define ICSSG_IET_MIN_VERIFY_TIME		1
+
+/**
+ * enum icssg_ietfpe_verify_states - status of MAC Merge Verify returned by firmware
+ * @ICSSG_IETFPE_STATE_UNKNOWN:
+ *	verification status is unknown
+ * @ICSSG_IETFPE_STATE_INITIAL:
+ *	Firmware returns this if verify state diagram is idle
+ * @ICSSG_IETFPE_STATE_VERIFYING:
+ *	Firmware returns this if verification is ongoing
+ * @ICSSG_IETFPE_STATE_SUCCEEDED:
+ *	Firmware returns this if verify state diagram completes verification
+ * @ICSSG_IETFPE_STATE_FAILED:
+ *	Firmware returns this if verify state diagram fails during verification
+ * @ICSSG_IETFPE_STATE_DISABLED:
+ *	verification is disabled by the driver
+ */
+enum icssg_ietfpe_verify_states {
+	ICSSG_IETFPE_STATE_UNKNOWN = 0,
+	ICSSG_IETFPE_STATE_INITIAL,
+	ICSSG_IETFPE_STATE_VERIFYING,
+	ICSSG_IETFPE_STATE_SUCCEEDED,
+	ICSSG_IETFPE_STATE_FAILED,
+	ICSSG_IETFPE_STATE_DISABLED
+};
+
+struct prueth_qos_mqprio {
+	struct tc_mqprio_qopt_offload mqprio;
+};
+
+struct prueth_qos_iet {
+	bool fpe_enabled;
+	bool mac_verify_configure;
+	u32 tx_min_frag_size;
+	u32 verify_time_ms;
+	bool fpe_active;
+	enum icssg_ietfpe_verify_states verify_status;
+	struct mutex fpe_lock;
+	u8 preemptible_tcs;
+};
+
+struct prueth_qos {
+	struct prueth_qos_iet iet;
+	struct prueth_qos_mqprio mqprio;
+};
+
+void icssg_qos_init(struct net_device *ndev);
+void icssg_qos_link_state_update(struct net_device *ndev);
+int icssg_qos_ndo_setup_tc(struct net_device *ndev, enum tc_setup_type type,
+			   void *type_data);
+int icssg_config_ietfpe(struct net_device *ndev, bool enable);
+#endif /* __NET_TI_ICSSG_QOS_H */
-- 
2.43.0

[PATCH net-next v6 2/2] net: ti: icssg-prueth: Add ethtool ops for Frame Preemption MAC Merge

[Meghana Malladi]

From: MD Danish Anwar <danishanwar@ti.com>

Add driver support for viewing and changing the MAC Merge sublayer
parameters via ethtool ops: .set_mm(), .get_mm() and .get_mm_stats().

The minimum size of non-final mPacket fragments supported by the firmware
without leading errors is 64 Bytes (including FCS). Verify time bounded to
1-128 ms per 802.3-2018 clause 30.14.1.6. Add a check to ensure
user passed tx_min_frag_size argument via ethtool, honors this.
Add pa stats registers to check statistics for preemption, which can be
dumped using ethtool ops.

Fix emac_get_stat_by_name() to return u64 instead of int and return 0 on
error instead of -EINVAL. This prevents invalid stat lookups from corrupting
output stats with signed error codes cast to u64. Error conditions are still
logged via netdev_err().

Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
Signed-off-by: Meghana Malladi <m-malladi@ti.com>
---

v6-v5:
- Initialize tx_min_frag_size and verify_time with valid values
  to avoid returning corrupted values during get_mm()
- Fix rx_min_frag_size to ETH_ZLEN excluding ETH_FCS_LEN
- Fix return codes for emac_set_mm()
All the above changes address the comments raised by sashiko

 drivers/net/ethernet/ti/icssg/icssg_ethtool.c | 106 ++++++++++++++++++
 drivers/net/ethernet/ti/icssg/icssg_prueth.h  |   7 +-
 drivers/net/ethernet/ti/icssg/icssg_qos.h     |  46 ++++++++
 drivers/net/ethernet/ti/icssg/icssg_stats.c   |   4 +-
 drivers/net/ethernet/ti/icssg/icssg_stats.h   |   7 +-
 .../net/ethernet/ti/icssg/icssg_switch_map.h  |   5 +
 6 files changed, 168 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/ti/icssg/icssg_ethtool.c b/drivers/net/ethernet/ti/icssg/icssg_ethtool.c
index b715af21d23ac..ee940051644d6 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_ethtool.c
+++ b/drivers/net/ethernet/ti/icssg/icssg_ethtool.c
@@ -294,6 +294,109 @@ static int emac_set_per_queue_coalesce(struct net_device *ndev, u32 queue,
 	return 0;
 }
 
+static int emac_get_mm(struct net_device *ndev, struct ethtool_mm_state *state)
+{
+	struct prueth_emac *emac = netdev_priv(ndev);
+	struct prueth_qos_iet *iet = &emac->qos.iet;
+	enum icssg_ietfpe_verify_states verify_status;
+
+	if (emac->is_sr1)
+		return -EOPNOTSUPP;
+
+	mutex_lock(&iet->fpe_lock);
+	state->tx_enabled = iet->fpe_enabled;
+	state->tx_min_frag_size = iet->tx_min_frag_size;
+	state->tx_active = iet->fpe_active;
+	state->verify_enabled = iet->mac_verify_configure;
+	state->verify_time = iet->verify_time_ms;
+	verify_status = iet->verify_status;
+	mutex_unlock(&iet->fpe_lock);
+
+	state->rx_min_frag_size = ETH_ZLEN;
+	state->pmac_enabled = true;
+
+	switch (verify_status) {
+	case ICSSG_IETFPE_STATE_DISABLED:
+		state->verify_status = ETHTOOL_MM_VERIFY_STATUS_DISABLED;
+		break;
+	case ICSSG_IETFPE_STATE_INITIAL:
+		state->verify_status = ETHTOOL_MM_VERIFY_STATUS_INITIAL;
+		break;
+	case ICSSG_IETFPE_STATE_VERIFYING:
+		state->verify_status = ETHTOOL_MM_VERIFY_STATUS_VERIFYING;
+		break;
+	case ICSSG_IETFPE_STATE_SUCCEEDED:
+		state->verify_status = ETHTOOL_MM_VERIFY_STATUS_SUCCEEDED;
+		break;
+	case ICSSG_IETFPE_STATE_FAILED:
+		state->verify_status = ETHTOOL_MM_VERIFY_STATUS_FAILED;
+		break;
+	default:
+		state->verify_status = ETHTOOL_MM_VERIFY_STATUS_UNKNOWN;
+		break;
+	}
+
+	/* 802.3-2018 clause 30.14.1.6, says that the aMACMergeVerifyTime
+	 * variable has a range between 1 and 128 ms inclusive. Limit to that.
+	 */
+	state->max_verify_time = ETHTOOL_MM_MAX_VERIFY_TIME_MS;
+
+	return 0;
+}
+
+static int emac_set_mm(struct net_device *ndev, struct ethtool_mm_cfg *cfg,
+		       struct netlink_ext_ack *extack)
+{
+	struct prueth_emac *emac = netdev_priv(ndev);
+	struct prueth_qos_iet *iet = &emac->qos.iet;
+	int err;
+
+	if (emac->is_sr1)
+		return -EOPNOTSUPP;
+
+	if (!cfg->pmac_enabled) {
+		NL_SET_ERR_MSG_MOD(extack, "preemptible MAC is always enabled");
+		return -EOPNOTSUPP;
+	}
+
+	err = icssg_qos_validate_tx_min_frag_size(cfg->tx_min_frag_size, extack);
+	if (err)
+		return err;
+
+	err = icssg_qos_validate_verify_time(cfg->verify_time, extack);
+	if (err)
+		return err;
+
+	mutex_lock(&iet->fpe_lock);
+	iet->verify_time_ms = cfg->verify_time;
+	iet->tx_min_frag_size = cfg->tx_min_frag_size;
+	iet->fpe_enabled = cfg->tx_enabled;
+	iet->mac_verify_configure = cfg->verify_enabled;
+	err = icssg_config_ietfpe(ndev, cfg->tx_enabled);
+	mutex_unlock(&iet->fpe_lock);
+
+	return err;
+}
+
+static void emac_get_mm_stats(struct net_device *ndev,
+			      struct ethtool_mm_stats *s)
+{
+	struct prueth_emac *emac = netdev_priv(ndev);
+
+	if (emac->is_sr1)
+		return;
+
+	if (!emac->prueth->pa_stats)
+		return;
+
+	/* MACMergeHoldCount stats is not tracked by the firmware */
+	s->MACMergeFrameAssOkCount = emac_get_stat_by_name(emac, "FW_PREEMPT_ASSEMBLY_OK");
+	s->MACMergeFrameAssErrorCount = emac_get_stat_by_name(emac, "FW_PREEMPT_ASSEMBLY_ERR");
+	s->MACMergeFragCountRx = emac_get_stat_by_name(emac, "FW_PREEMPT_FRAG_CNT_RX");
+	s->MACMergeFragCountTx = emac_get_stat_by_name(emac, "FW_PREEMPT_FRAG_CNT_TX");
+	s->MACMergeFrameSmdErrorCount = emac_get_stat_by_name(emac, "FW_PREEMPT_BAD_FRAG");
+}
+
 const struct ethtool_ops icssg_ethtool_ops = {
 	.get_drvinfo = emac_get_drvinfo,
 	.get_msglevel = emac_get_msglevel,
@@ -317,5 +420,8 @@ const struct ethtool_ops icssg_ethtool_ops = {
 	.set_eee = emac_set_eee,
 	.nway_reset = emac_nway_reset,
 	.get_rmon_stats = emac_get_rmon_stats,
+	.get_mm = emac_get_mm,
+	.set_mm = emac_set_mm,
+	.get_mm_stats = emac_get_mm_stats,
 };
 EXPORT_SYMBOL_GPL(icssg_ethtool_ops);
diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.h b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
index 85f7017d2c8e7..61320c252bec2 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_prueth.h
+++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
@@ -45,6 +45,7 @@
 #include "icss_iep.h"
 #include "icssg_switch_map.h"
 #include "icssg_qos.h"
+#include "icssg_stats.h"
 
 #define PRUETH_MAX_MTU          (2000 - ETH_HLEN - ETH_FCS_LEN)
 #define PRUETH_MIN_PKT_SIZE     (VLAN_ETH_ZLEN)
@@ -58,8 +59,8 @@
 
 #define ICSSG_MAX_RFLOWS	8	/* per slice */
 
-#define ICSSG_NUM_PA_STATS	32
-#define ICSSG_NUM_MIIG_STATS	60
+#define ICSSG_NUM_PA_STATS	ARRAY_SIZE(icssg_all_pa_stats)
+#define ICSSG_NUM_MIIG_STATS	ARRAY_SIZE(icssg_all_miig_stats)
 /* Number of ICSSG related stats */
 #define ICSSG_NUM_STATS (ICSSG_NUM_MIIG_STATS + ICSSG_NUM_PA_STATS)
 #define ICSSG_NUM_STANDARD_STATS 31
@@ -460,7 +461,7 @@ int emac_fdb_flow_id_updated(struct prueth_emac *emac);
 
 void icssg_stats_work_handler(struct work_struct *work);
 void emac_update_hardware_stats(struct prueth_emac *emac);
-int emac_get_stat_by_name(struct prueth_emac *emac, char *stat_name);
+u64 emac_get_stat_by_name(struct prueth_emac *emac, char *stat_name);
 
 /* Common functions */
 void prueth_cleanup_rx_chns(struct prueth_emac *emac,
diff --git a/drivers/net/ethernet/ti/icssg/icssg_qos.h b/drivers/net/ethernet/ti/icssg/icssg_qos.h
index 9355e96bbcda8..87ca031afcaa4 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_qos.h
+++ b/drivers/net/ethernet/ti/icssg/icssg_qos.h
@@ -13,6 +13,7 @@
 #define ICSSG_EXPRESS_Q_MASK_ALL		0xFF
 #define ICSSG_IET_MAX_VERIFY_TIME		128
 #define ICSSG_IET_MIN_VERIFY_TIME		1
+#define ICSSG_IET_MAX_TX_MIN_FRAG_SIZE		252
 
 /**
  * enum icssg_ietfpe_verify_states - status of MAC Merge Verify returned by firmware
@@ -63,4 +64,49 @@ void icssg_qos_link_state_update(struct net_device *ndev);
 int icssg_qos_ndo_setup_tc(struct net_device *ndev, enum tc_setup_type type,
 			   void *type_data);
 int icssg_config_ietfpe(struct net_device *ndev, bool enable);
+static inline int icssg_qos_validate_tx_min_frag_size(u32 min_frag_size,
+						      struct netlink_ext_ack *extack)
+{
+	/* Firmware takes min_frag_size including FCS length.
+	 * The firmware requires the fragment size (including FCS) to be
+	 * a multiple of 64 bytes. Since 64 bytes = ETH_ZLEN + ETH_FCS_LEN,
+	 * valid user-facing values are: 60, 124, 188, 252.
+	 */
+
+	if (min_frag_size < ETH_ZLEN) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "tx_min_frag_size must be at least 60 bytes");
+		return -EINVAL;
+	}
+
+	if (min_frag_size > ICSSG_IET_MAX_TX_MIN_FRAG_SIZE) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "tx_min_frag_size must not exceed 252 bytes");
+		return -EINVAL;
+	}
+
+	if ((min_frag_size + ETH_FCS_LEN) % (ETH_ZLEN + ETH_FCS_LEN)) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "tx_min_frag_size must be a multiple of 64 bytes minus 4");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static inline int icssg_qos_validate_verify_time(u32 verify_time_ms,
+						 struct netlink_ext_ack *extack)
+{
+	/* 802.3-2018 clause 30.14.1.6: aMACMergeVerifyTime must be
+	 * between 1 and 128 ms inclusive
+	 */
+	if (verify_time_ms < ICSSG_IET_MIN_VERIFY_TIME ||
+	    verify_time_ms > ICSSG_IET_MAX_VERIFY_TIME) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "verify_time must be between 1 and 128 ms");
+		return -EINVAL;
+	}
+
+	return 0;
+}
 #endif /* __NET_TI_ICSSG_QOS_H */
diff --git a/drivers/net/ethernet/ti/icssg/icssg_stats.c b/drivers/net/ethernet/ti/icssg/icssg_stats.c
index 7159baa0155cf..cfdb6f5dc5da1 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_stats.c
+++ b/drivers/net/ethernet/ti/icssg/icssg_stats.c
@@ -74,7 +74,7 @@ void icssg_stats_work_handler(struct work_struct *work)
 }
 EXPORT_SYMBOL_GPL(icssg_stats_work_handler);
 
-int emac_get_stat_by_name(struct prueth_emac *emac, char *stat_name)
+u64 emac_get_stat_by_name(struct prueth_emac *emac, char *stat_name)
 {
 	int i;
 
@@ -91,5 +91,5 @@ int emac_get_stat_by_name(struct prueth_emac *emac, char *stat_name)
 	}
 
 	netdev_err(emac->ndev, "Invalid stats %s\n", stat_name);
-	return -EINVAL;
+	return 0;
 }
diff --git a/drivers/net/ethernet/ti/icssg/icssg_stats.h b/drivers/net/ethernet/ti/icssg/icssg_stats.h
index 5ec0b38e0c67d..8073deac35c3e 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_stats.h
+++ b/drivers/net/ethernet/ti/icssg/icssg_stats.h
@@ -8,8 +8,6 @@
 #ifndef __NET_TI_ICSSG_STATS_H
 #define __NET_TI_ICSSG_STATS_H
 
-#include "icssg_prueth.h"
-
 #define STATS_TIME_LIMIT_1G_MS    25000    /* 25 seconds @ 1G */
 
 struct miig_stats_regs {
@@ -189,6 +187,11 @@ static const struct icssg_pa_stats icssg_all_pa_stats[] = {
 	ICSSG_PA_STATS(FW_INF_DROP_PRIOTAGGED),
 	ICSSG_PA_STATS(FW_INF_DROP_NOTAG),
 	ICSSG_PA_STATS(FW_INF_DROP_NOTMEMBER),
+	ICSSG_PA_STATS(FW_PREEMPT_BAD_FRAG),
+	ICSSG_PA_STATS(FW_PREEMPT_ASSEMBLY_ERR),
+	ICSSG_PA_STATS(FW_PREEMPT_FRAG_CNT_TX),
+	ICSSG_PA_STATS(FW_PREEMPT_ASSEMBLY_OK),
+	ICSSG_PA_STATS(FW_PREEMPT_FRAG_CNT_RX),
 	ICSSG_PA_STATS(FW_RX_EOF_SHORT_FRMERR),
 	ICSSG_PA_STATS(FW_RX_B0_DROP_EARLY_EOF),
 	ICSSG_PA_STATS(FW_TX_JUMBO_FRM_CUTOFF),
diff --git a/drivers/net/ethernet/ti/icssg/icssg_switch_map.h b/drivers/net/ethernet/ti/icssg/icssg_switch_map.h
index 7e053b8af3ece..855fd4ed0b3f6 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_switch_map.h
+++ b/drivers/net/ethernet/ti/icssg/icssg_switch_map.h
@@ -256,6 +256,11 @@
 #define FW_INF_DROP_PRIOTAGGED		0x0148
 #define FW_INF_DROP_NOTAG		0x0150
 #define FW_INF_DROP_NOTMEMBER		0x0158
+#define FW_PREEMPT_BAD_FRAG		0x0160
+#define FW_PREEMPT_ASSEMBLY_ERR		0x0168
+#define FW_PREEMPT_FRAG_CNT_TX		0x0170
+#define FW_PREEMPT_ASSEMBLY_OK		0x0178
+#define FW_PREEMPT_FRAG_CNT_RX		0x0180
 #define FW_RX_EOF_SHORT_FRMERR		0x0188
 #define FW_RX_B0_DROP_EARLY_EOF		0x0190
 #define FW_TX_JUMBO_FRM_CUTOFF		0x0198
-- 
2.43.0

Re: [PATCH net-next v6 1/2] net: ti: icssg-prueth: Add Frame Preemption MAC Merge support

[Maxime Chevallier]

Hi Meghana,

On 5/25/26 20:26, Meghana Malladi wrote:
> From: MD Danish Anwar <danishanwar@ti.com>
> 
> Introduce QoS infrastructure for Frame Preemption (FPE) support in
> the ICSSG Ethernet driver.
> 
> prueth_qos_iet tracks FPE enable/active state and verify state machine
> status via firmware-reported enum icssg_ietfpe_verify_states.
> icssg_config_ietfpe() configures IET FPE in firmware, triggers
> verify state machine based on ethtool MAC Merge parameters.
> Polls firmware verify status up to 3 times with verify_time_ms intervals
> and driver handles timeout by logging error and returning.
> In case of any failure during configuration for enable/disable,
> IET FPE falls back to disabled state.
> 
> For MQPRIO qdisc support all queues are express by default later
> gets override by user-provided preemptible_tcs bitmask via tc qdisc mask
> Preempt mask configuration: Maps traffic classes to queue express/preemptible
> state and applied only when FPE is active (Tx enabled)
> 
> Verify state machine re-triggers on link up/down events based on
> fpe_enabled and fpe_active flags, and for memory protection, fpe_lock
> serializes all FPE state mutations, preventing races between ethtool
> config, qdisc setup, and link events
> 
> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
> Signed-off-by: Meghana Malladi <m-malladi@ti.com>

There's quite a lot of checkpatch output for this patch, I'll let you 
browse through it :)

Also keep in mind that we still recommend 80 chars on net.

Besides that, I have a few comments, see below :)

> ---
> 
> v6-v5:
> - Balance fpe_lock mutex lifecycle on all error paths
> - Remove deadcode inside icssg_iet_set_preempt_mask()
> - Add fallback label inside icssg_config_ietfpe() to fix
>    stale state machine handling.
> - Replace netdev_err with netdev_info and netdev_dbg wherever
>    applicable
> - Remove EXPORT_SYMBOL_GPL for icssg_config_ietfpe()
> - Remove redundant code inside icssg_qos_init()
> - qdisc deletion path clears per-queue map as well.
> - Protect all read/writes to p_mqprio with a mutex
> All the above changes address the comments raised by sashiko
> 
>   drivers/net/ethernet/ti/Makefile             |   3 +-
>   drivers/net/ethernet/ti/icssg/icssg_common.c |   1 +
>   drivers/net/ethernet/ti/icssg/icssg_config.h |   9 -
>   drivers/net/ethernet/ti/icssg/icssg_prueth.c |   6 +
>   drivers/net/ethernet/ti/icssg/icssg_prueth.h |   2 +
>   drivers/net/ethernet/ti/icssg/icssg_qos.c    | 269 +++++++++++++++++++
>   drivers/net/ethernet/ti/icssg/icssg_qos.h    |  66 +++++
>   7 files changed, 346 insertions(+), 10 deletions(-)
>   create mode 100644 drivers/net/ethernet/ti/icssg/icssg_qos.c
>   create mode 100644 drivers/net/ethernet/ti/icssg/icssg_qos.h
> 
> diff --git a/drivers/net/ethernet/ti/Makefile b/drivers/net/ethernet/ti/Makefile
> index f4276c9a77620..d19bcd25c9d07 100644
> --- a/drivers/net/ethernet/ti/Makefile
> +++ b/drivers/net/ethernet/ti/Makefile
> @@ -46,6 +46,7 @@ icssg-y := icssg/icssg_common.o \
>   	   icssg/icssg_config.o \
>   	   icssg/icssg_mii_cfg.o \
>   	   icssg/icssg_stats.o \
> -	   icssg/icssg_ethtool.o
> +	   icssg/icssg_ethtool.o \
> +	   icssg/icssg_qos.o
>   
>   obj-$(CONFIG_TI_ICSS_IEP) += icssg/icss_iep.o
> diff --git a/drivers/net/ethernet/ti/icssg/icssg_common.c b/drivers/net/ethernet/ti/icssg/icssg_common.c
> index a28a608f9bf4b..c3ee97e96cd50 100644
> --- a/drivers/net/ethernet/ti/icssg/icssg_common.c
> +++ b/drivers/net/ethernet/ti/icssg/icssg_common.c
> @@ -1724,6 +1724,7 @@ void prueth_netdev_exit(struct prueth *prueth,
>   
>   	netif_napi_del(&emac->napi_rx);
>   
> +	mutex_destroy(&emac->qos.iet.fpe_lock);
>   	pruss_release_mem_region(prueth->pruss, &emac->dram);
>   	free_netdev(emac->ndev);
>   	prueth->emac[mac] = NULL;
> diff --git a/drivers/net/ethernet/ti/icssg/icssg_config.h b/drivers/net/ethernet/ti/icssg/icssg_config.h
> index 60d69744ffae2..1ac202f855ed4 100644
> --- a/drivers/net/ethernet/ti/icssg/icssg_config.h
> +++ b/drivers/net/ethernet/ti/icssg/icssg_config.h
> @@ -323,13 +323,4 @@ struct prueth_fdb_slot {
>   	u8 fid;
>   	u8 fid_c2;
>   } __packed;
> -
> -enum icssg_ietfpe_verify_states {
> -	ICSSG_IETFPE_STATE_UNKNOWN = 0,
> -	ICSSG_IETFPE_STATE_INITIAL,
> -	ICSSG_IETFPE_STATE_VERIFYING,
> -	ICSSG_IETFPE_STATE_SUCCEEDED,
> -	ICSSG_IETFPE_STATE_FAILED,
> -	ICSSG_IETFPE_STATE_DISABLED
> -};
>   #endif /* __NET_TI_ICSSG_CONFIG_H */
> diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.c b/drivers/net/ethernet/ti/icssg/icssg_prueth.c
> index 591be5c8056b4..39f379df923bf 100644
> --- a/drivers/net/ethernet/ti/icssg/icssg_prueth.c
> +++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.c
> @@ -392,6 +392,8 @@ static void emac_adjust_link(struct net_device *ndev)
>   		} else {
>   			icssg_set_port_state(emac, ICSSG_EMAC_PORT_DISABLE);
>   		}
> +
> +		icssg_qos_link_state_update(ndev);
>   	}
>   
>   	if (emac->link) {
> @@ -1652,6 +1654,7 @@ static const struct net_device_ops emac_netdev_ops = {
>   	.ndo_hwtstamp_get = icssg_ndo_get_ts_config,
>   	.ndo_hwtstamp_set = icssg_ndo_set_ts_config,
>   	.ndo_xsk_wakeup = prueth_xsk_wakeup,
> +	.ndo_setup_tc = icssg_qos_ndo_setup_tc,
>   };
>   
>   static int prueth_netdev_init(struct prueth *prueth,
> @@ -1686,6 +1689,8 @@ static int prueth_netdev_init(struct prueth *prueth,
>   
>   	INIT_DELAYED_WORK(&emac->stats_work, icssg_stats_work_handler);
>   
> +	icssg_qos_init(ndev);
> +
>   	ret = pruss_request_mem_region(prueth->pruss,
>   				       port == PRUETH_PORT_MII0 ?
>   				       PRUSS_MEM_DRAM0 : PRUSS_MEM_DRAM1,
> @@ -1793,6 +1798,7 @@ static int prueth_netdev_init(struct prueth *prueth,
>   free:
>   	pruss_release_mem_region(prueth->pruss, &emac->dram);
>   free_ndev:
> +	mutex_destroy(&emac->qos.iet.fpe_lock);
>   	emac->ndev = NULL;
>   	prueth->emac[mac] = NULL;
>   	free_netdev(ndev);
> diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.h b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
> index df93d15c5b786..85f7017d2c8e7 100644
> --- a/drivers/net/ethernet/ti/icssg/icssg_prueth.h
> +++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
> @@ -44,6 +44,7 @@
>   #include "icssg_config.h"
>   #include "icss_iep.h"
>   #include "icssg_switch_map.h"
> +#include "icssg_qos.h"
>   
>   #define PRUETH_MAX_MTU          (2000 - ETH_HLEN - ETH_FCS_LEN)
>   #define PRUETH_MIN_PKT_SIZE     (VLAN_ETH_ZLEN)
> @@ -254,6 +255,7 @@ struct prueth_emac {
>   	struct bpf_prog *xdp_prog;
>   	struct xdp_attachment_info xdpi;
>   	int xsk_qid;
> +	struct prueth_qos qos;
>   };
>   
>   /* The buf includes headroom compatible with both skb and xdpf */
> diff --git a/drivers/net/ethernet/ti/icssg/icssg_qos.c b/drivers/net/ethernet/ti/icssg/icssg_qos.c
> new file mode 100644
> index 0000000000000..2781abf39e9bb
> --- /dev/null
> +++ b/drivers/net/ethernet/ti/icssg/icssg_qos.c
> @@ -0,0 +1,269 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Texas Instruments ICSSG PRUETH QoS submodule
> + * Copyright (C) 2023 Texas Instruments Incorporated - http://www.ti.com/
> + */
> +
> +#include "icssg_prueth.h"
> +#include "icssg_switch_map.h"
> +
> +static void icssg_iet_set_preempt_mask(struct prueth_emac *emac)
> +{
> +	void __iomem *config = emac->dram.va + ICSSG_CONFIG_OFFSET;
> +	struct prueth_qos_mqprio *p_mqprio = &emac->qos.mqprio;
> +	struct tc_mqprio_qopt *qopt = &p_mqprio->mqprio.qopt;
> +	struct prueth_qos_iet *iet = &emac->qos.iet;
> +	int prempt_mask = 0, i;
> +	u8 tc, num_tc;
> +
> +	if (!iet->preemptible_tcs)
> +		goto reset_hw;
> +
> +	if (iet->fpe_active) {
> +		/* Configure the queues based on the preemptible tc map set by the user */
> +		num_tc = p_mqprio->mqprio.qopt.num_tc;
> +		for (tc = 0; tc < num_tc; tc++) {
> +			/* check if the tc is preemptive or not */
> +			if (iet->preemptible_tcs & BIT(tc)) {
> +				for (i = qopt->offset[tc]; i < qopt->offset[tc] + qopt->count[tc]; i++) {
> +					/* Set all the queues in this tc as preemptive queues */
> +					writeb(BIT(4), config + EXPRESS_PRE_EMPTIVE_Q_MAP + i);
> +				}
> +			} else {
> +				/* Set all the queues in this tc as express queues */
> +				for (i = qopt->offset[tc]; i < qopt->offset[tc] + qopt->count[tc]; i++) {
> +					writeb(0, config + EXPRESS_PRE_EMPTIVE_Q_MAP + i);
> +					prempt_mask |= BIT(i);
> +				}
> +			}
> +			netdev_set_tc_queue(emac->ndev, tc, qopt->count[tc], qopt->offset[tc]);
> +		}
> +		writeb(prempt_mask, config + EXPRESS_PRE_EMPTIVE_Q_MASK);
> +		return;
> +	}
> +
> +reset_hw:
> +	/* Reset to default: all queues as express */
> +	for (i = 0; i < ICSSG_MAX_TC_QUEUES; i++)
> +		writeb(0, config + EXPRESS_PRE_EMPTIVE_Q_MAP + i);
> +	writeb(ICSSG_EXPRESS_Q_MASK_ALL, config + EXPRESS_PRE_EMPTIVE_Q_MASK);
> +}
> +
> +static int icssg_iet_verify_wait(struct prueth_emac *emac)
> +{
> +	void __iomem *config = emac->dram.va + ICSSG_CONFIG_OFFSET;
> +	struct prueth_qos_iet *iet = &emac->qos.iet;
> +	int try = 3;
> +
> +	do {
> +		msleep(iet->verify_time_ms);
> +		iet->verify_status = readb(config + PRE_EMPTION_VERIFY_STATUS);
> +		if (iet->verify_status == ICSSG_IETFPE_STATE_SUCCEEDED)
> +			return 0;
> +	} while (--try > 0);

You can replace that whole loop with a readb_poll_timeout, to avoid
open-coding it.

> +
> +	netdev_err(emac->ndev, "MAC Verify timeout\n");
> +	return -ETIMEDOUT;
> +}
> +
> +/* Direct synchronous configuration of IET FPE.
> + * Caller must hold iet->fpe_lock.
> + */
> +int icssg_config_ietfpe(struct net_device *ndev, bool enable)
> +{
> +	struct prueth_emac *emac = netdev_priv(ndev);
> +	void __iomem *config = emac->dram.va + ICSSG_CONFIG_OFFSET;
> +	struct prueth_qos_iet *iet = &emac->qos.iet;
> +	int ret;
> +	u8 val;
> +
> +	lockdep_assert_held(&iet->fpe_lock);
> +
> +	if (!netif_running(ndev)) {
> +		netdev_dbg(ndev, "cannot change IET/FPE state when interface is down\n");
> +		return 0;
> +	}
> +
> +	/* Update FPE Tx enable bit (PRE_EMPTION_ENABLE_TX) if
> +	 * fpe_enabled is set to enable MM in Tx direction
> +	 */
> +	writeb(enable ? 1 : 0, config + PRE_EMPTION_ENABLE_TX);
> +
> +	/* If FPE is to be enabled, first configure MAC Verify state
> +	 * machine in firmware as firmware kicks the Verify process
> +	 * as soon as ICSSG_EMAC_PORT_PREMPT_TX_ENABLE command is
> +	 * received.
> +	 */
> +	if (enable && iet->mac_verify_configure) {
> +		writeb(1, config + PRE_EMPTION_ENABLE_VERIFY);
> +		writew(iet->tx_min_frag_size + ETH_FCS_LEN,
> +		       config + PRE_EMPTION_ADD_FRAG_SIZE_LOCAL);
> +		writel(iet->verify_time_ms, config + PRE_EMPTION_VERIFY_TIME);
> +	} else {
> +		writeb(0, config + PRE_EMPTION_ENABLE_VERIFY);
> +		iet->verify_status = ICSSG_IETFPE_STATE_DISABLED;
> +	}
> +
> +	/* Send command to enable FPE Tx side. Rx is always enabled */
> +	ret = icssg_set_port_state(emac,
> +				   enable ? ICSSG_EMAC_PORT_PREMPT_TX_ENABLE :
> +					    ICSSG_EMAC_PORT_PREMPT_TX_DISABLE);
> +	if (ret) {
> +		netdev_err(ndev, "TX preempt %s command failed\n",
> +			   str_enable_disable(enable));
> +		goto fallback;
> +	}
> +
> +	if (enable && iet->mac_verify_configure) {
> +		ret = icssg_iet_verify_wait(emac);
> +		if (ret) {
> +			netdev_err(ndev, "MAC Verification failed with timeout\n");
> +			goto disable_tx;
> +		}
> +	} else if (enable) {
> +		/* Give firmware some time to update PRE_EMPTION_ACTIVE_TX state */
> +		usleep_range(100, 200);
> +	}
> +
> +	if (enable) {
> +		val = readb(config + PRE_EMPTION_ACTIVE_TX);
> +		if (val != 1) {
> +			netdev_err(ndev,
> +				   "Firmware fails to activate IET/FPE\n");
> +			ret = -EIO;
> +			goto disable_tx;
> +		}
> +		iet->fpe_active = true;
> +	} else {
> +		iet->fpe_active = false;
> +	}
> +
> +	icssg_iet_set_preempt_mask(emac);
> +	netdev_info(ndev, "IET FPE %s successfully\n",
> +		   str_enable_disable(iet->fpe_active));
> +	return ret;
> +
> +disable_tx:
> +	icssg_set_port_state(emac, ICSSG_EMAC_PORT_PREMPT_TX_DISABLE);
> +fallback:
> +	writeb(0, config + PRE_EMPTION_ENABLE_TX);
> +	writeb(0, config + PRE_EMPTION_ENABLE_VERIFY);
> +	iet->verify_status = ICSSG_IETFPE_STATE_DISABLED;
> +	iet->fpe_active =  false;
> +	return ret;
> +}
> +
> +void icssg_qos_init(struct net_device *ndev)
> +{
> +	struct prueth_emac *emac = netdev_priv(ndev);
> +	struct prueth_qos_iet *iet = &emac->qos.iet;
> +
> +	mutex_init(&iet->fpe_lock);
> +	/* Set default values to prevent garbage values during .get_mm() */
> +	mutex_lock(&iet->fpe_lock);
> +	iet->verify_time_ms = ICSSG_IET_MAX_VERIFY_TIME;
> +	iet->tx_min_frag_size = ETH_ZLEN;
> +	mutex_unlock(&iet->fpe_lock);
> +}
> +EXPORT_SYMBOL_GPL(icssg_qos_init);
> +
> +static int icssg_iet_change_preemptible_tcs(struct prueth_emac *emac)
> +{
> +	struct prueth_qos_iet *iet = &emac->qos.iet;
> +	int ret;
> +
> +	mutex_lock(&iet->fpe_lock);
> +	ret = icssg_config_ietfpe(emac->ndev, iet->fpe_enabled);
> +	mutex_unlock(&iet->fpe_lock);
> +
> +	return ret;
> +}
> +
> +static int emac_tc_query_caps(struct net_device *ndev, void *type_data)
> +{
> +	struct tc_query_caps_base *base = type_data;
> +
> +	switch (base->type) {
> +	case TC_SETUP_QDISC_MQPRIO: {
> +		struct tc_mqprio_caps *caps = base->caps;
> +
> +		caps->validate_queue_counts = true;
> +		return 0;
> +	}
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +}
> +
> +static int emac_tc_setup_mqprio(struct net_device *ndev, void *type_data)
> +{
> +	struct prueth_emac *emac = netdev_priv(ndev);
> +	struct prueth_qos_mqprio *p_mqprio = &emac->qos.mqprio;
> +	struct tc_mqprio_qopt_offload *mqprio = type_data;
> +	struct prueth_qos_iet *iet = &emac->qos.iet;
> +	int ret;
> +
> +	/* Validate parameters */
> +	if (mqprio->qopt.num_tc > ICSSG_MAX_TC_QUEUES) {
> +		netdev_err(ndev, "Number of traffic classes (%u) exceeds hardware limit\n",
> +			   mqprio->qopt.num_tc);
> +		return -EINVAL;
> +	}
> +
> +	if (mqprio->flags & TC_MQPRIO_F_SHAPER) {
> +		netdev_err(ndev, "traffic shaping is not supported\n");
> +		return -EINVAL;

Maybe -EOPNOTSUPP ?

> +	}
> +
> +	if (mqprio->flags & (TC_MQPRIO_F_MIN_RATE | TC_MQPRIO_F_MAX_RATE)) {
> +		netdev_err(ndev, "per-queue rate limiting is not supported\n");
> +		return -EINVAL;

Same

> +	}
> +
> +	if (!mqprio->qopt.num_tc) {
> +		netdev_reset_tc(ndev);
> +	} else {
> +		netdev_set_num_tc(ndev, mqprio->qopt.num_tc);
> +	}
> +
> +	mutex_lock(&iet->fpe_lock);
> +	if (!mqprio->qopt.num_tc) {
> +		iet->preemptible_tcs = 0;
> +	} else {
> +		memcpy(&p_mqprio->mqprio, mqprio, sizeof(*mqprio));
> +		iet->preemptible_tcs = mqprio->preemptible_tcs;
> +	}
> +	mutex_unlock(&iet->fpe_lock);
> +
> +	netdev_dbg(ndev, "dev->num_tc %u dev->real_num_tx_queues %u\n",
> +		   ndev->num_tc, ndev->real_num_tx_queues);
> +
> +	ret = icssg_iet_change_preemptible_tcs(emac);
> +	return ret;

Simplify this with :

	return icssg_iet_change_preemptible_tcs(emac);

> +}
> +
> +int icssg_qos_ndo_setup_tc(struct net_device *ndev, enum tc_setup_type type,
> +			   void *type_data)
> +{
> +	switch (type) {
> +	case TC_QUERY_CAPS:
> +		return emac_tc_query_caps(ndev, type_data);
> +	case TC_SETUP_QDISC_MQPRIO:
> +		return emac_tc_setup_mqprio(ndev, type_data);
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +}
> +EXPORT_SYMBOL_GPL(icssg_qos_ndo_setup_tc);
> +
> +void icssg_qos_link_state_update(struct net_device *ndev)
> +{
> +	struct prueth_emac *emac = netdev_priv(ndev);
> +	struct prueth_qos_iet *iet = &emac->qos.iet;
> +	int ret;
> +
> +	ret = icssg_iet_change_preemptible_tcs(emac);
> +	if (ret)
> +		netdev_dbg(ndev, "IET FPE %s failed\n",
> +		   str_enable_disable(iet->fpe_active));
> +}
> +EXPORT_SYMBOL_GPL(icssg_qos_link_state_update);
> diff --git a/drivers/net/ethernet/ti/icssg/icssg_qos.h b/drivers/net/ethernet/ti/icssg/icssg_qos.h
> new file mode 100644
> index 0000000000000..9355e96bbcda8
> --- /dev/null
> +++ b/drivers/net/ethernet/ti/icssg/icssg_qos.h
> @@ -0,0 +1,66 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/* Copyright (C) 2023 Texas Instruments Incorporated - http://www.ti.com/
> + */
> +
> +#ifndef __NET_TI_ICSSG_QOS_H
> +#define __NET_TI_ICSSG_QOS_H
> +
> +#include <linux/atomic.h>
> +#include <linux/netdevice.h>
> +#include <net/pkt_sched.h>
> +
> +#define ICSSG_MAX_TC_QUEUES			8
> +#define ICSSG_EXPRESS_Q_MASK_ALL		0xFF
> +#define ICSSG_IET_MAX_VERIFY_TIME		128
> +#define ICSSG_IET_MIN_VERIFY_TIME		1
> +
> +/**
> + * enum icssg_ietfpe_verify_states - status of MAC Merge Verify returned by firmware
> + * @ICSSG_IETFPE_STATE_UNKNOWN:
> + *	verification status is unknown
> + * @ICSSG_IETFPE_STATE_INITIAL:
> + *	Firmware returns this if verify state diagram is idle
> + * @ICSSG_IETFPE_STATE_VERIFYING:
> + *	Firmware returns this if verification is ongoing
> + * @ICSSG_IETFPE_STATE_SUCCEEDED:
> + *	Firmware returns this if verify state diagram completes verification
> + * @ICSSG_IETFPE_STATE_FAILED:
> + *	Firmware returns this if verify state diagram fails during verification
> + * @ICSSG_IETFPE_STATE_DISABLED:
> + *	verification is disabled by the driver
> + */
> +enum icssg_ietfpe_verify_states {
> +	ICSSG_IETFPE_STATE_UNKNOWN = 0,
> +	ICSSG_IETFPE_STATE_INITIAL,
> +	ICSSG_IETFPE_STATE_VERIFYING,
> +	ICSSG_IETFPE_STATE_SUCCEEDED,
> +	ICSSG_IETFPE_STATE_FAILED,
> +	ICSSG_IETFPE_STATE_DISABLED
> +};
> +
> +struct prueth_qos_mqprio {
> +	struct tc_mqprio_qopt_offload mqprio;
> +};
> +
> +struct prueth_qos_iet {
> +	bool fpe_enabled;
> +	bool mac_verify_configure;
> +	u32 tx_min_frag_size;
> +	u32 verify_time_ms;
> +	bool fpe_active;
> +	enum icssg_ietfpe_verify_states verify_status;
> +	struct mutex fpe_lock;

Checkpatch already says it, but you need to document what this
mutex is protecting.

> +	u8 preemptible_tcs;
> +};
> +
> +struct prueth_qos {
> +	struct prueth_qos_iet iet;
> +	struct prueth_qos_mqprio mqprio;
> +};
> +
> +void icssg_qos_init(struct net_device *ndev);
> +void icssg_qos_link_state_update(struct net_device *ndev);
> +int icssg_qos_ndo_setup_tc(struct net_device *ndev, enum tc_setup_type type,
> +			   void *type_data);
> +int icssg_config_ietfpe(struct net_device *ndev, bool enable);
> +#endif /* __NET_TI_ICSSG_QOS_H */

Thanks,

Maxime

Re: [PATCH net-next v6 2/2] net: ti: icssg-prueth: Add ethtool ops for Frame Preemption MAC Merge

[Maxime Chevallier]

Hi,

On 5/25/26 20:27, Meghana Malladi wrote:
> From: MD Danish Anwar <danishanwar@ti.com>
> 
> Add driver support for viewing and changing the MAC Merge sublayer
> parameters via ethtool ops: .set_mm(), .get_mm() and .get_mm_stats().
> 
> The minimum size of non-final mPacket fragments supported by the firmware
> without leading errors is 64 Bytes (including FCS). Verify time bounded to
> 1-128 ms per 802.3-2018 clause 30.14.1.6. Add a check to ensure
> user passed tx_min_frag_size argument via ethtool, honors this.
> Add pa stats registers to check statistics for preemption, which can be
> dumped using ethtool ops.
> 
> Fix emac_get_stat_by_name() to return u64 instead of int and return 0 on
> error instead of -EINVAL. This prevents invalid stat lookups from corrupting
> output stats with signed error codes cast to u64. Error conditions are still
> logged via netdev_err().
> 
> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
> Signed-off-by: Meghana Malladi <m-malladi@ti.com>
> ---
> 
> v6-v5:
> - Initialize tx_min_frag_size and verify_time with valid values
>    to avoid returning corrupted values during get_mm()
> - Fix rx_min_frag_size to ETH_ZLEN excluding ETH_FCS_LEN
> - Fix return codes for emac_set_mm()
> All the above changes address the comments raised by sashiko
> 
>   drivers/net/ethernet/ti/icssg/icssg_ethtool.c | 106 ++++++++++++++++++
>   drivers/net/ethernet/ti/icssg/icssg_prueth.h  |   7 +-
>   drivers/net/ethernet/ti/icssg/icssg_qos.h     |  46 ++++++++
>   drivers/net/ethernet/ti/icssg/icssg_stats.c   |   4 +-
>   drivers/net/ethernet/ti/icssg/icssg_stats.h   |   7 +-
>   .../net/ethernet/ti/icssg/icssg_switch_map.h  |   5 +
>   6 files changed, 168 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/net/ethernet/ti/icssg/icssg_ethtool.c b/drivers/net/ethernet/ti/icssg/icssg_ethtool.c
> index b715af21d23ac..ee940051644d6 100644
> --- a/drivers/net/ethernet/ti/icssg/icssg_ethtool.c
> +++ b/drivers/net/ethernet/ti/icssg/icssg_ethtool.c
> @@ -294,6 +294,109 @@ static int emac_set_per_queue_coalesce(struct net_device *ndev, u32 queue,
>   	return 0;
>   }
>   
> +static int emac_get_mm(struct net_device *ndev, struct ethtool_mm_state *state)
> +{
> +	struct prueth_emac *emac = netdev_priv(ndev);
> +	struct prueth_qos_iet *iet = &emac->qos.iet;
> +	enum icssg_ietfpe_verify_states verify_status;
> +
> +	if (emac->is_sr1)
> +		return -EOPNOTSUPP;
> +
> +	mutex_lock(&iet->fpe_lock);
> +	state->tx_enabled = iet->fpe_enabled;
> +	state->tx_min_frag_size = iet->tx_min_frag_size;
> +	state->tx_active = iet->fpe_active;
> +	state->verify_enabled = iet->mac_verify_configure;
> +	state->verify_time = iet->verify_time_ms;
> +	verify_status = iet->verify_status;
> +	mutex_unlock(&iet->fpe_lock);
> +
> +	state->rx_min_frag_size = ETH_ZLEN;
> +	state->pmac_enabled = true;
> +
> +	switch (verify_status) {
> +	case ICSSG_IETFPE_STATE_DISABLED:
> +		state->verify_status = ETHTOOL_MM_VERIFY_STATUS_DISABLED;
> +		break;
> +	case ICSSG_IETFPE_STATE_INITIAL:
> +		state->verify_status = ETHTOOL_MM_VERIFY_STATUS_INITIAL;
> +		break;
> +	case ICSSG_IETFPE_STATE_VERIFYING:
> +		state->verify_status = ETHTOOL_MM_VERIFY_STATUS_VERIFYING;
> +		break;
> +	case ICSSG_IETFPE_STATE_SUCCEEDED:
> +		state->verify_status = ETHTOOL_MM_VERIFY_STATUS_SUCCEEDED;
> +		break;
> +	case ICSSG_IETFPE_STATE_FAILED:
> +		state->verify_status = ETHTOOL_MM_VERIFY_STATUS_FAILED;
> +		break;
> +	default:
> +		state->verify_status = ETHTOOL_MM_VERIFY_STATUS_UNKNOWN;
> +		break;
> +	}
> +
> +	/* 802.3-2018 clause 30.14.1.6, says that the aMACMergeVerifyTime
> +	 * variable has a range between 1 and 128 ms inclusive. Limit to that.
> +	 */
> +	state->max_verify_time = ETHTOOL_MM_MAX_VERIFY_TIME_MS;
> +
> +	return 0;
> +}
> +
> +static int emac_set_mm(struct net_device *ndev, struct ethtool_mm_cfg *cfg,
> +		       struct netlink_ext_ack *extack)
> +{
> +	struct prueth_emac *emac = netdev_priv(ndev);
> +	struct prueth_qos_iet *iet = &emac->qos.iet;
> +	int err;
> +
> +	if (emac->is_sr1)
> +		return -EOPNOTSUPP;
> +
> +	if (!cfg->pmac_enabled) {
> +		NL_SET_ERR_MSG_MOD(extack, "preemptible MAC is always enabled");
> +		return -EOPNOTSUPP;
> +	}
> +
> +	err = icssg_qos_validate_tx_min_frag_size(cfg->tx_min_frag_size, extack);
> +	if (err)
> +		return err;
> +
> +	err = icssg_qos_validate_verify_time(cfg->verify_time, extack);
> +	if (err)
> +		return err;

The ethnl code already validates the verify_time :

https://elixir.bootlin.com/linux/v7.0.9/source/net/ethtool/mm.c#L153

> +
> +	mutex_lock(&iet->fpe_lock);
> +	iet->verify_time_ms = cfg->verify_time;
> +	iet->tx_min_frag_size = cfg->tx_min_frag_size;
> +	iet->fpe_enabled = cfg->tx_enabled;
> +	iet->mac_verify_configure = cfg->verify_enabled;
> +	err = icssg_config_ietfpe(ndev, cfg->tx_enabled);
> +	mutex_unlock(&iet->fpe_lock);
> +
> +	return err;
> +}
> +
> +static void emac_get_mm_stats(struct net_device *ndev,
> +			      struct ethtool_mm_stats *s)
> +{
> +	struct prueth_emac *emac = netdev_priv(ndev);
> +
> +	if (emac->is_sr1)
> +		return;
> +
> +	if (!emac->prueth->pa_stats)
> +		return;
> +
> +	/* MACMergeHoldCount stats is not tracked by the firmware */
> +	s->MACMergeFrameAssOkCount = emac_get_stat_by_name(emac, "FW_PREEMPT_ASSEMBLY_OK");
> +	s->MACMergeFrameAssErrorCount = emac_get_stat_by_name(emac, "FW_PREEMPT_ASSEMBLY_ERR");
> +	s->MACMergeFragCountRx = emac_get_stat_by_name(emac, "FW_PREEMPT_FRAG_CNT_RX");
> +	s->MACMergeFragCountTx = emac_get_stat_by_name(emac, "FW_PREEMPT_FRAG_CNT_TX");
> +	s->MACMergeFrameSmdErrorCount = emac_get_stat_by_name(emac, "FW_PREEMPT_BAD_FRAG");
> +}
> +
>   const struct ethtool_ops icssg_ethtool_ops = {
>   	.get_drvinfo = emac_get_drvinfo,
>   	.get_msglevel = emac_get_msglevel,
> @@ -317,5 +420,8 @@ const struct ethtool_ops icssg_ethtool_ops = {
>   	.set_eee = emac_set_eee,
>   	.nway_reset = emac_nway_reset,
>   	.get_rmon_stats = emac_get_rmon_stats,
> +	.get_mm = emac_get_mm,
> +	.set_mm = emac_set_mm,
> +	.get_mm_stats = emac_get_mm_stats,
>   };
>   EXPORT_SYMBOL_GPL(icssg_ethtool_ops);
> diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.h b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
> index 85f7017d2c8e7..61320c252bec2 100644
> --- a/drivers/net/ethernet/ti/icssg/icssg_prueth.h
> +++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
> @@ -45,6 +45,7 @@
>   #include "icss_iep.h"
>   #include "icssg_switch_map.h"
>   #include "icssg_qos.h"
> +#include "icssg_stats.h"
>   
>   #define PRUETH_MAX_MTU          (2000 - ETH_HLEN - ETH_FCS_LEN)
>   #define PRUETH_MIN_PKT_SIZE     (VLAN_ETH_ZLEN)
> @@ -58,8 +59,8 @@
>   
>   #define ICSSG_MAX_RFLOWS	8	/* per slice */
>   
> -#define ICSSG_NUM_PA_STATS	32
> -#define ICSSG_NUM_MIIG_STATS	60
> +#define ICSSG_NUM_PA_STATS	ARRAY_SIZE(icssg_all_pa_stats)
> +#define ICSSG_NUM_MIIG_STATS	ARRAY_SIZE(icssg_all_miig_stats)
>   /* Number of ICSSG related stats */
>   #define ICSSG_NUM_STATS (ICSSG_NUM_MIIG_STATS + ICSSG_NUM_PA_STATS)
>   #define ICSSG_NUM_STANDARD_STATS 31
> @@ -460,7 +461,7 @@ int emac_fdb_flow_id_updated(struct prueth_emac *emac);
>   
>   void icssg_stats_work_handler(struct work_struct *work);
>   void emac_update_hardware_stats(struct prueth_emac *emac);
> -int emac_get_stat_by_name(struct prueth_emac *emac, char *stat_name);
> +u64 emac_get_stat_by_name(struct prueth_emac *emac, char *stat_name);
>   
>   /* Common functions */
>   void prueth_cleanup_rx_chns(struct prueth_emac *emac,
> diff --git a/drivers/net/ethernet/ti/icssg/icssg_qos.h b/drivers/net/ethernet/ti/icssg/icssg_qos.h
> index 9355e96bbcda8..87ca031afcaa4 100644
> --- a/drivers/net/ethernet/ti/icssg/icssg_qos.h
> +++ b/drivers/net/ethernet/ti/icssg/icssg_qos.h
> @@ -13,6 +13,7 @@
>   #define ICSSG_EXPRESS_Q_MASK_ALL		0xFF
>   #define ICSSG_IET_MAX_VERIFY_TIME		128
>   #define ICSSG_IET_MIN_VERIFY_TIME		1
> +#define ICSSG_IET_MAX_TX_MIN_FRAG_SIZE		252
>   
>   /**
>    * enum icssg_ietfpe_verify_states - status of MAC Merge Verify returned by firmware
> @@ -63,4 +64,49 @@ void icssg_qos_link_state_update(struct net_device *ndev);
>   int icssg_qos_ndo_setup_tc(struct net_device *ndev, enum tc_setup_type type,
>   			   void *type_data);
>   int icssg_config_ietfpe(struct net_device *ndev, bool enable);
> +static inline int icssg_qos_validate_tx_min_frag_size(u32 min_frag_size,
> +						      struct netlink_ext_ack *extack)
> +{
> +	/* Firmware takes min_frag_size including FCS length.
> +	 * The firmware requires the fragment size (including FCS) to be
> +	 * a multiple of 64 bytes. Since 64 bytes = ETH_ZLEN + ETH_FCS_LEN,
> +	 * valid user-facing values are: 60, 124, 188, 252.
> +	 */
> +
> +	if (min_frag_size < ETH_ZLEN) {
> +		NL_SET_ERR_MSG_MOD(extack,
> +				   "tx_min_frag_size must be at least 60 bytes");
> +		return -EINVAL;
> +	}
> +
> +	if (min_frag_size > ICSSG_IET_MAX_TX_MIN_FRAG_SIZE) {
> +		NL_SET_ERR_MSG_MOD(extack,
> +				   "tx_min_frag_size must not exceed 252 bytes");
> +		return -EINVAL;
> +	}
> +
> +	if ((min_frag_size + ETH_FCS_LEN) % (ETH_ZLEN + ETH_FCS_LEN)) {
> +		NL_SET_ERR_MSG_MOD(extack,
> +				   "tx_min_frag_size must be a multiple of 64 bytes minus 4");
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}

Is there any reason this helper is in a header file instead
of being directly in icssg_ethtool.c ?

> +
> +static inline int icssg_qos_validate_verify_time(u32 verify_time_ms,
> +						 struct netlink_ext_ack *extack)
> +{
> +	/* 802.3-2018 clause 30.14.1.6: aMACMergeVerifyTime must be
> +	 * between 1 and 128 ms inclusive
> +	 */
> +	if (verify_time_ms < ICSSG_IET_MIN_VERIFY_TIME ||
> +	    verify_time_ms > ICSSG_IET_MAX_VERIFY_TIME) {
> +		NL_SET_ERR_MSG_MOD(extack,
> +				   "verify_time must be between 1 and 128 ms");
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}

And this shouldn't be needed as the ethnl mm code already validates
these boundaries, as they are straight from the standard.

>   #endif /* __NET_TI_ICSSG_QOS_H */
> diff --git a/drivers/net/ethernet/ti/icssg/icssg_stats.c b/drivers/net/ethernet/ti/icssg/icssg_stats.c
> index 7159baa0155cf..cfdb6f5dc5da1 100644
> --- a/drivers/net/ethernet/ti/icssg/icssg_stats.c
> +++ b/drivers/net/ethernet/ti/icssg/icssg_stats.c
> @@ -74,7 +74,7 @@ void icssg_stats_work_handler(struct work_struct *work)
>   }
>   EXPORT_SYMBOL_GPL(icssg_stats_work_handler);
>   
> -int emac_get_stat_by_name(struct prueth_emac *emac, char *stat_name)
> +u64 emac_get_stat_by_name(struct prueth_emac *emac, char *stat_name)
>   {
>   	int i;
>   
> @@ -91,5 +91,5 @@ int emac_get_stat_by_name(struct prueth_emac *emac, char *stat_name)
>   	}
>   
>   	netdev_err(emac->ndev, "Invalid stats %s\n", stat_name);
> -	return -EINVAL;
> +	return 0;
>   }
> diff --git a/drivers/net/ethernet/ti/icssg/icssg_stats.h b/drivers/net/ethernet/ti/icssg/icssg_stats.h
> index 5ec0b38e0c67d..8073deac35c3e 100644
> --- a/drivers/net/ethernet/ti/icssg/icssg_stats.h
> +++ b/drivers/net/ethernet/ti/icssg/icssg_stats.h
> @@ -8,8 +8,6 @@
>   #ifndef __NET_TI_ICSSG_STATS_H
>   #define __NET_TI_ICSSG_STATS_H
>   
> -#include "icssg_prueth.h"
> -
>   #define STATS_TIME_LIMIT_1G_MS    25000    /* 25 seconds @ 1G */
>   
>   struct miig_stats_regs {
> @@ -189,6 +187,11 @@ static const struct icssg_pa_stats icssg_all_pa_stats[] = {
>   	ICSSG_PA_STATS(FW_INF_DROP_PRIOTAGGED),
>   	ICSSG_PA_STATS(FW_INF_DROP_NOTAG),
>   	ICSSG_PA_STATS(FW_INF_DROP_NOTMEMBER),
> +	ICSSG_PA_STATS(FW_PREEMPT_BAD_FRAG),
> +	ICSSG_PA_STATS(FW_PREEMPT_ASSEMBLY_ERR),
> +	ICSSG_PA_STATS(FW_PREEMPT_FRAG_CNT_TX),
> +	ICSSG_PA_STATS(FW_PREEMPT_ASSEMBLY_OK),
> +	ICSSG_PA_STATS(FW_PREEMPT_FRAG_CNT_RX),
>   	ICSSG_PA_STATS(FW_RX_EOF_SHORT_FRMERR),
>   	ICSSG_PA_STATS(FW_RX_B0_DROP_EARLY_EOF),
>   	ICSSG_PA_STATS(FW_TX_JUMBO_FRM_CUTOFF),
> diff --git a/drivers/net/ethernet/ti/icssg/icssg_switch_map.h b/drivers/net/ethernet/ti/icssg/icssg_switch_map.h
> index 7e053b8af3ece..855fd4ed0b3f6 100644
> --- a/drivers/net/ethernet/ti/icssg/icssg_switch_map.h
> +++ b/drivers/net/ethernet/ti/icssg/icssg_switch_map.h
> @@ -256,6 +256,11 @@
>   #define FW_INF_DROP_PRIOTAGGED		0x0148
>   #define FW_INF_DROP_NOTAG		0x0150
>   #define FW_INF_DROP_NOTMEMBER		0x0158
> +#define FW_PREEMPT_BAD_FRAG		0x0160
> +#define FW_PREEMPT_ASSEMBLY_ERR		0x0168
> +#define FW_PREEMPT_FRAG_CNT_TX		0x0170
> +#define FW_PREEMPT_ASSEMBLY_OK		0x0178
> +#define FW_PREEMPT_FRAG_CNT_RX		0x0180
>   #define FW_RX_EOF_SHORT_FRMERR		0x0188
>   #define FW_RX_B0_DROP_EARLY_EOF		0x0190
>   #define FW_TX_JUMBO_FRM_CUTOFF		0x0198

Maxime

Re: [PATCH net-next v6 1/2] net: ti: icssg-prueth: Add Frame Preemption MAC Merge support

[Andrew Lunn]

> > +++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
> > @@ -44,6 +44,7 @@
> >   #include "icssg_config.h"
> >   #include "icss_iep.h"
> >   #include "icssg_switch_map.h"
> > +#include "icssg_qos.h"
> >   #define PRUETH_MAX_MTU          (2000 - ETH_HLEN - ETH_FCS_LEN)

Sorry for hijacking another message, but the indentation looks odd
here.

	Andrew

Re: [PATCH net-next v6 0/2] Add Frame Preemption MAC Merge support for ICSSG

[Simon Horman]

On Mon, May 25, 2026 at 11:56:58PM +0530, Meghana Malladi wrote:
> This patch series adds QoS support to the ICSSG PRUETH driver.
> The first patch implements mqprio qdisc handling and TC offload hooks
> so userspace can request TC mappings and queue counts.
> 
> It also integrates a driver-side mechanism to program the firmware
> with the IET/FPE preemption mask and to kick the firmware verify state
> machine when frame preemption is enabled. The second patch adds ethtool
> perations for the MAC Merge (Frame Preemption) sublayer, exposing .get_mm,
> .set_mm and .get_mm_stats so admins can view and change MAC Merge
> parameters and retrieve preemption statistics.
> 
> v5: https://lore.kernel.org/all/20260430111723.497113-1-m-malladi@ti.com/
> 
> MD Danish Anwar (2):
>   net: ti: icssg-prueth: Add Frame Preemption MAC Merge support
>   net: ti: icssg-prueth: Add ethtool ops for Frame Preemption MAC Merge

Hi Meghana and MD,

There is another round of AI-generated reviews for this patch-set available at
https://netdev-ai.bots.linux.dev/ and https://sashiko.dev/

I would appreciate it if you could look over them and address any
issues that are either introduced by this patch-set, or directly
impact it.

I would not suggest expanding this patchset to address any other
pre-existing issues, but rather address them separately as appropriate.