[PATCH iwl-next v5 0/9] igc: Add support for Frame Preemption feature in IGC

[PATCH iwl-next v5 0/9] igc: Add support for Frame Preemption feature in IGC

[Faizal Rahim]

Introduces support for the FPE feature in the IGC driver.

The patches aligns with the upstream FPE API:
https://patchwork.kernel.org/project/netdevbpf/cover/20230220122343.1156614-1-vladimir.oltean@nxp.com/
https://patchwork.kernel.org/project/netdevbpf/cover/20230119122705.73054-1-vladimir.oltean@nxp.com/

It builds upon earlier work:
https://patchwork.kernel.org/project/netdevbpf/cover/20220520011538.1098888-1-vinicius.gomes@intel.com/

The patch series adds the following functionalities to the IGC driver:
a) Configure FPE using `ethtool --set-mm`.
b) Display FPE settings via `ethtool --show-mm`.
c) View FPE statistics using `ethtool --include-statistics --show-mm'.
e) Block setting preemptible tc in taprio since it is not supported yet.
   Existing code already blocks it in mqprio.

Change Log:
v4 -> v5:
- Remove "igc: Add support for preemptible traffic class in taprio" patch (Vladimir)
- Add a new patch "igc: Block setting preemptible traffic classes in taprio" (Vladimir)
- Add kernel-doc for mmsv api (Vladimir)
- olininfo_status to use host byte order (Simon)
- status_error should host byte type (Simon)
- Some code was misplaced in the wrong patch (Vladimir)
- Mix of tabs and spaces in patch description (Vladimir)
- Created igc_is_pmac_enabled() to reduce code repetition (Vladimir)

v3 -> v4:
- Fix compilation warnings introduced by this patch series

v2 -> v3:
- Implement configure_tx() mmsv callback (Vladimir)
- Use static_branch_inc() and static_branch_dec() (Vladimir)
- Add adapter->fpe.mmsv.pmac_enabled as extra check (Vladimir)
- Remove unnecessary error check in igc_fpe_init_tx_descriptor() (Vladimir)
- Additional places to use FIELD_PREP() instead of manual bit manipulation (Vladimir)
- IGC_TXD_POPTS_SMD_V and IGC_TXD_POPTS_SMD_R type change to enum (Vladimir)
- Remove unnecessary netif_running() check in igc_fpe_xmit_frame (Vladimir)
- Rate limit print in igc_fpe_send_mpacket (Vladimir)

v1 -> v2:
- Extract the stmmac verification logic into a common library (Vladimir)
- igc to use common library for verification (Vladimir)
- Fix syntax for kernel-doc to use "Return:" (Vladimir)
- Use FIELD_GET instead of manual bit masking (Vladimir)
- Don't assign 0 to statistics counter in igc_ethtool_get_mm_stats() (Vladimir)
- Use pmac-enabled as a condition to allow MAC address value 0 (Vladimir)
- Define macro register value in increasing value order (Vladimir)
- Fix tx-min-frag-size handling for igc (Vladimir)
- Handle link state changes with verification in igc (Vladimir)
- Add static key for fast path code (Vladimir)
- rx_min_frag_size get from constant (Vladimir)

v1: https://patchwork.kernel.org/project/netdevbpf/cover/20241216064720.931522-1-faizal.abdul.rahim@linux.intel.com/
v2: https://patchwork.kernel.org/project/netdevbpf/cover/20250205100524.1138523-1-faizal.abdul.rahim@linux.intel.com/
v3: https://patchwork.kernel.org/project/netdevbpf/cover/20250207165649.2245320-1-faizal.abdul.rahim@linux.intel.com/
v4: https://patchwork.kernel.org/project/netdevbpf/cover/20250210070207.2615418-1-faizal.abdul.rahim@linux.intel.com/

Faizal Rahim (8):
  igc: Rename xdp_get_tx_ring() for non-xdp usage
  igc: Optimize the TX packet buffer utilization
  igc: Set the RX packet buffer size for TSN mode
  igc: Add support for frame preemption verification
  igc: Add support to set tx-min-frag-size
  igc: Add support to get MAC Merge data via ethtool
  igc: Add support to get frame preemption statistics via ethtool
  igc: Block setting preemptible traffic class in taprio

Vladimir Oltean (1):
  net: ethtool: mm: extract stmmac verification logic into common
    library

 drivers/net/ethernet/intel/igc/igc.h          |  15 +-
 drivers/net/ethernet/intel/igc/igc_base.h     |   1 +
 drivers/net/ethernet/intel/igc/igc_defines.h  |  15 +-
 drivers/net/ethernet/intel/igc/igc_ethtool.c  |  76 ++++++
 drivers/net/ethernet/intel/igc/igc_main.c     |  67 +++++-
 drivers/net/ethernet/intel/igc/igc_regs.h     |  16 ++
 drivers/net/ethernet/intel/igc/igc_tsn.c      | 190 ++++++++++++++-
 drivers/net/ethernet/intel/igc/igc_tsn.h      |  52 ++++
 drivers/net/ethernet/stmicro/stmmac/stmmac.h  |  16 +-
 .../ethernet/stmicro/stmmac/stmmac_ethtool.c  |  41 +---
 .../net/ethernet/stmicro/stmmac/stmmac_fpe.c  | 174 +++-----------
 .../net/ethernet/stmicro/stmmac/stmmac_fpe.h  |   5 -
 .../net/ethernet/stmicro/stmmac/stmmac_main.c |   8 +-
 include/linux/ethtool.h                       | 131 ++++++++++
 net/ethtool/mm.c                              | 227 +++++++++++++++++-
 15 files changed, 817 insertions(+), 217 deletions(-)

--
2.34.1

[PATCH iwl-next v5 1/9] net: ethtool: mm: extract stmmac verification logic into common library

[Faizal Rahim]

From: Vladimir Oltean <vladimir.oltean@nxp.com>

It appears that stmmac is not the only hardware which requires a
software-driven verification state machine for the MAC Merge layer.

While on the one hand it's good to encourage hardware implementations,
on the other hand it's quite difficult to tolerate multiple drivers
implementing independently fairly non-trivial logic.

Extract the hardware-independent logic from stmmac into library code and
put it in ethtool. Name the state structure "mmsv" for MAC Merge
Software Verification. Let this expose an operations structure for
executing the hardware stuff: sync hardware with the tx_active boolean
(result of verification process), enable/disable the pMAC, send mPackets,
notify library of external events (reception of mPackets), as well as
link state changes.

Note that it is assumed that the external events are received in hardirq
context. If they are not, it is probably a good idea to disable hardirqs
when calling ethtool_mmsv_event_handle(), because the library does not
do so.

Also, the MM software verification process has no business with the
tx_min_frag_size, that is all the driver's to handle.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Co-developed-by: Choong Yong Liang <yong.liang.choong@linux.intel.com>
Signed-off-by: Choong Yong Liang <yong.liang.choong@linux.intel.com>
Co-developed-by: Faizal Rahim <faizal.abdul.rahim@linux.intel.com>
Signed-off-by: Faizal Rahim <faizal.abdul.rahim@linux.intel.com>
Tested-by: Choong Yong Liang <yong.liang.choong@linux.intel.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac.h  |  16 +-
 .../ethernet/stmicro/stmmac/stmmac_ethtool.c  |  41 +---
 .../net/ethernet/stmicro/stmmac/stmmac_fpe.c  | 174 +++-----------
 .../net/ethernet/stmicro/stmmac/stmmac_fpe.h  |   5 -
 .../net/ethernet/stmicro/stmmac/stmmac_main.c |   8 +-
 include/linux/ethtool.h                       | 131 ++++++++++
 net/ethtool/mm.c                              | 225 +++++++++++++++++-
 7 files changed, 399 insertions(+), 201 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index f05cae103d83..c9cc41af258a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -147,21 +147,9 @@ struct stmmac_channel {
 };
 
 struct stmmac_fpe_cfg {
-	/* Serialize access to MAC Merge state between ethtool requests
-	 * and link state updates.
-	 */
-	spinlock_t lock;
-
+	struct ethtool_mmsv mmsv;
 	const struct stmmac_fpe_reg *reg;
-	u32 fpe_csr;				/* MAC_FPE_CTRL_STS reg cache */
-
-	enum ethtool_mm_verify_status status;
-	struct timer_list verify_timer;
-	bool verify_enabled;
-	int verify_retries;
-	bool pmac_enabled;
-	u32 verify_time;
-	bool tx_enabled;
+	u32 fpe_csr;	/* MAC_FPE_CTRL_STS reg cache */
 };
 
 struct stmmac_tc_entry {
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
index 918a32f8fda8..8e6b052e00d6 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
@@ -1210,37 +1210,17 @@ static int stmmac_get_mm(struct net_device *ndev,
 			 struct ethtool_mm_state *state)
 {
 	struct stmmac_priv *priv = netdev_priv(ndev);
-	unsigned long flags;
 	u32 frag_size;
 
 	if (!stmmac_fpe_supported(priv))
 		return -EOPNOTSUPP;
 
-	spin_lock_irqsave(&priv->fpe_cfg.lock, flags);
+	ethtool_mmsv_get_mm(&priv->fpe_cfg.mmsv, state);
 
-	state->max_verify_time = STMMAC_FPE_MM_MAX_VERIFY_TIME_MS;
-	state->verify_enabled = priv->fpe_cfg.verify_enabled;
-	state->pmac_enabled = priv->fpe_cfg.pmac_enabled;
-	state->verify_time = priv->fpe_cfg.verify_time;
-	state->tx_enabled = priv->fpe_cfg.tx_enabled;
-	state->verify_status = priv->fpe_cfg.status;
 	state->rx_min_frag_size = ETH_ZLEN;
-
-	/* FPE active if common tx_enabled and
-	 * (verification success or disabled(forced))
-	 */
-	if (state->tx_enabled &&
-	    (state->verify_status == ETHTOOL_MM_VERIFY_STATUS_SUCCEEDED ||
-	     state->verify_status == ETHTOOL_MM_VERIFY_STATUS_DISABLED))
-		state->tx_active = true;
-	else
-		state->tx_active = false;
-
 	frag_size = stmmac_fpe_get_add_frag_size(priv);
 	state->tx_min_frag_size = ethtool_mm_frag_size_add_to_min(frag_size);
 
-	spin_unlock_irqrestore(&priv->fpe_cfg.lock, flags);
-
 	return 0;
 }
 
@@ -1248,8 +1228,6 @@ static int stmmac_set_mm(struct net_device *ndev, struct ethtool_mm_cfg *cfg,
 			 struct netlink_ext_ack *extack)
 {
 	struct stmmac_priv *priv = netdev_priv(ndev);
-	struct stmmac_fpe_cfg *fpe_cfg = &priv->fpe_cfg;
-	unsigned long flags;
 	u32 frag_size;
 	int err;
 
@@ -1258,23 +1236,8 @@ static int stmmac_set_mm(struct net_device *ndev, struct ethtool_mm_cfg *cfg,
 	if (err)
 		return err;
 
-	/* Wait for the verification that's currently in progress to finish */
-	timer_shutdown_sync(&fpe_cfg->verify_timer);
-
-	spin_lock_irqsave(&fpe_cfg->lock, flags);
-
-	fpe_cfg->verify_enabled = cfg->verify_enabled;
-	fpe_cfg->pmac_enabled = cfg->pmac_enabled;
-	fpe_cfg->verify_time = cfg->verify_time;
-	fpe_cfg->tx_enabled = cfg->tx_enabled;
-
-	if (!cfg->verify_enabled)
-		fpe_cfg->status = ETHTOOL_MM_VERIFY_STATUS_DISABLED;
-
+	ethtool_mmsv_set_mm(&priv->fpe_cfg.mmsv, cfg);
 	stmmac_fpe_set_add_frag_size(priv, frag_size);
-	stmmac_fpe_apply(priv);
-
-	spin_unlock_irqrestore(&fpe_cfg->lock, flags);
 
 	return 0;
 }
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.c
index 3a4bee029c7f..75b470ee621a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.c
@@ -27,12 +27,6 @@
 #define STMMAC_MAC_FPE_CTRL_STS_SVER	BIT(1)
 #define STMMAC_MAC_FPE_CTRL_STS_EFPE	BIT(0)
 
-/* FPE link-partner hand-shaking mPacket type */
-enum stmmac_mpacket_type {
-	MPACKET_VERIFY = 0,
-	MPACKET_RESPONSE = 1,
-};
-
 struct stmmac_fpe_reg {
 	const u32 mac_fpe_reg;		/* offset of MAC_FPE_CTRL_STS */
 	const u32 mtl_fpe_reg;		/* offset of MTL_FPE_CTRL_STS */
@@ -48,10 +42,10 @@ bool stmmac_fpe_supported(struct stmmac_priv *priv)
 		priv->hw->mac->fpe_map_preemption_class;
 }
 
-static void stmmac_fpe_configure(struct stmmac_priv *priv, bool tx_enable,
-				 bool pmac_enable)
+static void stmmac_fpe_configure_tx(struct ethtool_mmsv *mmsv, bool tx_enable)
 {
-	struct stmmac_fpe_cfg *cfg = &priv->fpe_cfg;
+	struct stmmac_fpe_cfg *cfg = container_of(mmsv, struct stmmac_fpe_cfg, mmsv);
+	struct stmmac_priv *priv = container_of(cfg, struct stmmac_priv, fpe_cfg);
 	const struct stmmac_fpe_reg *reg = cfg->reg;
 	u32 num_rxq = priv->plat->rx_queues_to_use;
 	void __iomem *ioaddr = priv->ioaddr;
@@ -68,6 +62,15 @@ static void stmmac_fpe_configure(struct stmmac_priv *priv, bool tx_enable,
 		cfg->fpe_csr = 0;
 	}
 	writel(cfg->fpe_csr, ioaddr + reg->mac_fpe_reg);
+}
+
+static void stmmac_fpe_configure_pmac(struct ethtool_mmsv *mmsv, bool pmac_enable)
+{
+	struct stmmac_fpe_cfg *cfg = container_of(mmsv, struct stmmac_fpe_cfg, mmsv);
+	struct stmmac_priv *priv = container_of(cfg, struct stmmac_priv, fpe_cfg);
+	const struct stmmac_fpe_reg *reg = cfg->reg;
+	void __iomem *ioaddr = priv->ioaddr;
+	u32 value;
 
 	value = readl(ioaddr + reg->int_en_reg);
 
@@ -85,47 +88,45 @@ static void stmmac_fpe_configure(struct stmmac_priv *priv, bool tx_enable,
 	writel(value, ioaddr + reg->int_en_reg);
 }
 
-static void stmmac_fpe_send_mpacket(struct stmmac_priv *priv,
-				    enum stmmac_mpacket_type type)
+static void stmmac_fpe_send_mpacket(struct ethtool_mmsv *mmsv,
+				    enum ethtool_mpacket type)
 {
-	const struct stmmac_fpe_reg *reg = priv->fpe_cfg.reg;
+	struct stmmac_fpe_cfg *cfg = container_of(mmsv, struct stmmac_fpe_cfg, mmsv);
+	struct stmmac_priv *priv = container_of(cfg, struct stmmac_priv, fpe_cfg);
+	const struct stmmac_fpe_reg *reg = cfg->reg;
 	void __iomem *ioaddr = priv->ioaddr;
-	u32 value = priv->fpe_cfg.fpe_csr;
+	u32 value = cfg->fpe_csr;
 
-	if (type == MPACKET_VERIFY)
+	if (type == ETHTOOL_MPACKET_VERIFY)
 		value |= STMMAC_MAC_FPE_CTRL_STS_SVER;
-	else if (type == MPACKET_RESPONSE)
+	else if (type == ETHTOOL_MPACKET_RESPONSE)
 		value |= STMMAC_MAC_FPE_CTRL_STS_SRSP;
 
 	writel(value, ioaddr + reg->mac_fpe_reg);
 }
 
+static const struct ethtool_mmsv_ops stmmac_mmsv_ops = {
+	.configure_tx = stmmac_fpe_configure_tx,
+	.configure_pmac = stmmac_fpe_configure_pmac,
+	.send_mpacket = stmmac_fpe_send_mpacket,
+};
+
 static void stmmac_fpe_event_status(struct stmmac_priv *priv, int status)
 {
 	struct stmmac_fpe_cfg *fpe_cfg = &priv->fpe_cfg;
+	struct ethtool_mmsv *mmsv = &fpe_cfg->mmsv;
 
-	/* This is interrupt context, just spin_lock() */
-	spin_lock(&fpe_cfg->lock);
-
-	if (!fpe_cfg->pmac_enabled || status == FPE_EVENT_UNKNOWN)
-		goto unlock_out;
+	if (status == FPE_EVENT_UNKNOWN)
+		return;
 
-	/* LP has sent verify mPacket */
 	if ((status & FPE_EVENT_RVER) == FPE_EVENT_RVER)
-		stmmac_fpe_send_mpacket(priv, MPACKET_RESPONSE);
+		ethtool_mmsv_event_handle(mmsv, ETHTOOL_MMSV_LP_SENT_VERIFY_MPACKET);
 
-	/* Local has sent verify mPacket */
-	if ((status & FPE_EVENT_TVER) == FPE_EVENT_TVER &&
-	    fpe_cfg->status != ETHTOOL_MM_VERIFY_STATUS_SUCCEEDED)
-		fpe_cfg->status = ETHTOOL_MM_VERIFY_STATUS_VERIFYING;
+	if ((status & FPE_EVENT_TVER) == FPE_EVENT_TVER)
+		ethtool_mmsv_event_handle(mmsv, ETHTOOL_MMSV_LD_SENT_VERIFY_MPACKET);
 
-	/* LP has sent response mPacket */
-	if ((status & FPE_EVENT_RRSP) == FPE_EVENT_RRSP &&
-	    fpe_cfg->status == ETHTOOL_MM_VERIFY_STATUS_VERIFYING)
-		fpe_cfg->status = ETHTOOL_MM_VERIFY_STATUS_SUCCEEDED;
-
-unlock_out:
-	spin_unlock(&fpe_cfg->lock);
+	if ((status & FPE_EVENT_RRSP) == FPE_EVENT_RRSP)
+		ethtool_mmsv_event_handle(mmsv, ETHTOOL_MMSV_LP_SENT_RESPONSE_MPACKET);
 }
 
 void stmmac_fpe_irq_status(struct stmmac_priv *priv)
@@ -164,119 +165,16 @@ void stmmac_fpe_irq_status(struct stmmac_priv *priv)
 	stmmac_fpe_event_status(priv, status);
 }
 
-/**
- * stmmac_fpe_verify_timer - Timer for MAC Merge verification
- * @t:  timer_list struct containing private info
- *
- * Verify the MAC Merge capability in the local TX direction, by
- * transmitting Verify mPackets up to 3 times. Wait until link
- * partner responds with a Response mPacket, otherwise fail.
- */
-static void stmmac_fpe_verify_timer(struct timer_list *t)
-{
-	struct stmmac_fpe_cfg *fpe_cfg = from_timer(fpe_cfg, t, verify_timer);
-	struct stmmac_priv *priv = container_of(fpe_cfg, struct stmmac_priv,
-						fpe_cfg);
-	unsigned long flags;
-	bool rearm = false;
-
-	spin_lock_irqsave(&fpe_cfg->lock, flags);
-
-	switch (fpe_cfg->status) {
-	case ETHTOOL_MM_VERIFY_STATUS_INITIAL:
-	case ETHTOOL_MM_VERIFY_STATUS_VERIFYING:
-		if (fpe_cfg->verify_retries != 0) {
-			stmmac_fpe_send_mpacket(priv, MPACKET_VERIFY);
-			rearm = true;
-		} else {
-			fpe_cfg->status = ETHTOOL_MM_VERIFY_STATUS_FAILED;
-		}
-
-		fpe_cfg->verify_retries--;
-		break;
-
-	case ETHTOOL_MM_VERIFY_STATUS_SUCCEEDED:
-		stmmac_fpe_configure(priv, true, true);
-		break;
-
-	default:
-		break;
-	}
-
-	if (rearm) {
-		mod_timer(&fpe_cfg->verify_timer,
-			  jiffies + msecs_to_jiffies(fpe_cfg->verify_time));
-	}
-
-	spin_unlock_irqrestore(&fpe_cfg->lock, flags);
-}
-
-static void stmmac_fpe_verify_timer_arm(struct stmmac_fpe_cfg *fpe_cfg)
-{
-	if (fpe_cfg->pmac_enabled && fpe_cfg->tx_enabled &&
-	    fpe_cfg->verify_enabled &&
-	    fpe_cfg->status != ETHTOOL_MM_VERIFY_STATUS_FAILED &&
-	    fpe_cfg->status != ETHTOOL_MM_VERIFY_STATUS_SUCCEEDED) {
-		timer_setup(&fpe_cfg->verify_timer, stmmac_fpe_verify_timer, 0);
-		mod_timer(&fpe_cfg->verify_timer, jiffies);
-	}
-}
-
 void stmmac_fpe_init(struct stmmac_priv *priv)
 {
-	priv->fpe_cfg.verify_retries = STMMAC_FPE_MM_MAX_VERIFY_RETRIES;
-	priv->fpe_cfg.verify_time = STMMAC_FPE_MM_MAX_VERIFY_TIME_MS;
-	priv->fpe_cfg.status = ETHTOOL_MM_VERIFY_STATUS_DISABLED;
-	timer_setup(&priv->fpe_cfg.verify_timer, stmmac_fpe_verify_timer, 0);
-	spin_lock_init(&priv->fpe_cfg.lock);
+	ethtool_mmsv_init(&priv->fpe_cfg.mmsv, priv->dev,
+			  &stmmac_mmsv_ops);
 
 	if ((!priv->fpe_cfg.reg || !priv->hw->mac->fpe_map_preemption_class) &&
 	    priv->dma_cap.fpesel)
 		dev_info(priv->device, "FPE is not supported by driver.\n");
 }
 
-void stmmac_fpe_apply(struct stmmac_priv *priv)
-{
-	struct stmmac_fpe_cfg *fpe_cfg = &priv->fpe_cfg;
-
-	/* If verification is disabled, configure FPE right away.
-	 * Otherwise let the timer code do it.
-	 */
-	if (!fpe_cfg->verify_enabled) {
-		stmmac_fpe_configure(priv, fpe_cfg->tx_enabled,
-				     fpe_cfg->pmac_enabled);
-	} else {
-		fpe_cfg->status = ETHTOOL_MM_VERIFY_STATUS_INITIAL;
-		fpe_cfg->verify_retries = STMMAC_FPE_MM_MAX_VERIFY_RETRIES;
-
-		if (netif_running(priv->dev))
-			stmmac_fpe_verify_timer_arm(fpe_cfg);
-	}
-}
-
-void stmmac_fpe_link_state_handle(struct stmmac_priv *priv, bool is_up)
-{
-	struct stmmac_fpe_cfg *fpe_cfg = &priv->fpe_cfg;
-	unsigned long flags;
-
-	timer_shutdown_sync(&fpe_cfg->verify_timer);
-
-	spin_lock_irqsave(&fpe_cfg->lock, flags);
-
-	if (is_up && fpe_cfg->pmac_enabled) {
-		/* VERIFY process requires pmac enabled when NIC comes up */
-		stmmac_fpe_configure(priv, false, true);
-
-		/* New link => maybe new partner => new verification process */
-		stmmac_fpe_apply(priv);
-	} else {
-		/* No link => turn off EFPE */
-		stmmac_fpe_configure(priv, false, false);
-	}
-
-	spin_unlock_irqrestore(&fpe_cfg->lock, flags);
-}
-
 int stmmac_fpe_get_add_frag_size(struct stmmac_priv *priv)
 {
 	const struct stmmac_fpe_reg *reg = priv->fpe_cfg.reg;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.h b/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.h
index b884eac7142d..3fc46acf7001 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.h
@@ -9,15 +9,10 @@
 #include <linux/types.h>
 #include <linux/netdevice.h>
 
-#define STMMAC_FPE_MM_MAX_VERIFY_RETRIES	3
-#define STMMAC_FPE_MM_MAX_VERIFY_TIME_MS	128
-
 struct stmmac_priv;
 
-void stmmac_fpe_link_state_handle(struct stmmac_priv *priv, bool is_up);
 bool stmmac_fpe_supported(struct stmmac_priv *priv);
 void stmmac_fpe_init(struct stmmac_priv *priv);
-void stmmac_fpe_apply(struct stmmac_priv *priv);
 void stmmac_fpe_irq_status(struct stmmac_priv *priv);
 int stmmac_fpe_get_add_frag_size(struct stmmac_priv *priv);
 void stmmac_fpe_set_add_frag_size(struct stmmac_priv *priv, u32 add_frag_size);
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index d04543e5697b..8f723f9e84ba 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -992,7 +992,7 @@ static void stmmac_mac_link_down(struct phylink_config *config,
 		stmmac_set_eee_pls(priv, priv->hw, false);
 
 	if (stmmac_fpe_supported(priv))
-		stmmac_fpe_link_state_handle(priv, false);
+		ethtool_mmsv_link_state_handle(&priv->fpe_cfg.mmsv, false);
 }
 
 static void stmmac_mac_link_up(struct phylink_config *config,
@@ -1100,7 +1100,7 @@ static void stmmac_mac_link_up(struct phylink_config *config,
 		stmmac_set_eee_pls(priv, priv->hw, true);
 
 	if (stmmac_fpe_supported(priv))
-		stmmac_fpe_link_state_handle(priv, true);
+		ethtool_mmsv_link_state_handle(&priv->fpe_cfg.mmsv, true);
 
 	if (priv->plat->flags & STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY)
 		stmmac_hwtstamp_correct_latency(priv, priv);
@@ -4097,7 +4097,7 @@ static int stmmac_release(struct net_device *dev)
 	stmmac_release_ptp(priv);
 
 	if (stmmac_fpe_supported(priv))
-		timer_shutdown_sync(&priv->fpe_cfg.verify_timer);
+		ethtool_mmsv_stop(&priv->fpe_cfg.mmsv);
 
 	pm_runtime_put(priv->device);
 
@@ -7822,7 +7822,7 @@ int stmmac_suspend(struct device *dev)
 	rtnl_unlock();
 
 	if (stmmac_fpe_supported(priv))
-		timer_shutdown_sync(&priv->fpe_cfg.verify_timer);
+		ethtool_mmsv_stop(&priv->fpe_cfg.mmsv);
 
 	priv->speed = SPEED_UNKNOWN;
 	return 0;
diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 870994cc3ef7..8023fb18dd91 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -17,9 +17,13 @@
 #include <linux/compat.h>
 #include <linux/if_ether.h>
 #include <linux/netlink.h>
+#include <linux/timer_types.h>
 #include <uapi/linux/ethtool.h>
 #include <uapi/linux/net_tstamp.h>
 
+#define ETHTOOL_MM_MAX_VERIFY_TIME_MS		128
+#define ETHTOOL_MM_MAX_VERIFY_RETRIES		3
+
 struct compat_ethtool_rx_flow_spec {
 	u32		flow_type;
 	union ethtool_flow_union h_u;
@@ -710,6 +714,133 @@ struct ethtool_mm_stats {
 	u64 MACMergeHoldCount;
 };
 
+enum ethtool_mmsv_event {
+	ETHTOOL_MMSV_LP_SENT_VERIFY_MPACKET,
+	ETHTOOL_MMSV_LD_SENT_VERIFY_MPACKET,
+	ETHTOOL_MMSV_LP_SENT_RESPONSE_MPACKET,
+};
+
+/* MAC Merge verification mPacket type */
+enum ethtool_mpacket {
+	ETHTOOL_MPACKET_VERIFY,
+	ETHTOOL_MPACKET_RESPONSE,
+};
+
+struct ethtool_mmsv;
+
+/**
+ * struct ethtool_mmsv_ops - Operations for MAC Merge Software Verification
+ * @configure_tx: Driver callback for the event where the preemptible TX
+ *		  becomes active or inactive. Preemptible traffic
+ *		  classes must be committed to hardware only while
+ *		  preemptible TX is active.
+ * @configure_pmac: Driver callback for the event where the pMAC state
+ *		    changes as result of an administrative setting
+ *		    (ethtool) or a call to ethtool_mmsv_link_state_handle().
+ * @send_mpacket: Driver-provided method for sending a Verify or a Response
+ *		  mPacket.
+ */
+struct ethtool_mmsv_ops {
+	void (*configure_tx)(struct ethtool_mmsv *mmsv, bool tx_active);
+	void (*configure_pmac)(struct ethtool_mmsv *mmsv, bool pmac_enabled);
+	void (*send_mpacket)(struct ethtool_mmsv *mmsv, enum ethtool_mpacket mpacket);
+};
+
+/**
+ * struct ethtool_mmsv - MAC Merge Software Verification
+ * @ops: operations for MAC Merge Software Verification
+ * @dev: pointer to net_device structure
+ * @lock: serialize access to MAC Merge state between
+ *	  ethtool requests and link state updates.
+ * @status: current verification FSM state
+ * @verify_timer: timer for verification in local TX direction
+ * @verify_enabled: indicates if verification is enabled
+ * @verify_retries: number of retries for verification
+ * @pmac_enabled: indicates if the preemptible MAC is enabled
+ * @verify_time: time for verification in milliseconds
+ * @tx_enabled: indicates if transmission is enabled
+ */
+struct ethtool_mmsv {
+	const struct ethtool_mmsv_ops *ops;
+	struct net_device *dev;
+	spinlock_t lock;
+	enum ethtool_mm_verify_status status;
+	struct timer_list verify_timer;
+	bool verify_enabled;
+	int verify_retries;
+	bool pmac_enabled;
+	u32 verify_time;
+	bool tx_enabled;
+};
+
+/**
+ * ethtool_mmsv_stop() - Stop MAC Merge Software Verification
+ * @mmsv: MAC Merge Software Verification state
+ *
+ * Drivers should call this method in a state where the hardware is
+ * about to lose state, like ndo_stop() or suspend(), and turning off
+ * MAC Merge features would be superfluous. Otherwise, prefer
+ * ethtool_mmsv_link_state_handle() with up=false.
+ */
+void ethtool_mmsv_stop(struct ethtool_mmsv *mmsv);
+
+/**
+ * ethtool_mmsv_link_state_handle() - Inform MAC Merge Software Verification
+ *				      of link state changes
+ * @mmsv: MAC Merge Software Verification state
+ * @up: True if device carrier is up and able to pass verification packets
+ *
+ * Calling context is expected to be from a thread, interrupts enabled.
+ */
+void ethtool_mmsv_link_state_handle(struct ethtool_mmsv *mmsv, bool up);
+
+/**
+ * ethtool_mmsv_event_handle() - Inform MAC Merge Software Verification
+ *				 of interrupt-based events
+ * @mmsv: MAC Merge Software Verification state
+ * @event: Event which took place (packet transmission or reception)
+ *
+ * Calling context expects to have interrupts disabled.
+ */
+void ethtool_mmsv_event_handle(struct ethtool_mmsv *mmsv,
+			       enum ethtool_mmsv_event event);
+
+/**
+ * ethtool_mmsv_get_mm() - get_mm() hook for MAC Merge Software Verification
+ * @mmsv: MAC Merge Software Verification state
+ * @state: see struct ethtool_mm_state
+ *
+ * Drivers are expected to call this from their ethtool_ops :: get_mm()
+ * method.
+ */
+void ethtool_mmsv_get_mm(struct ethtool_mmsv *mmsv,
+			 struct ethtool_mm_state *state);
+
+/**
+ * ethtool_mmsv_set_mm() - set_mm() hook for MAC Merge Software Verification
+ * @mmsv: MAC Merge Software Verification state
+ * @cfg: see struct ethtool_mm_cfg
+ *
+ * Drivers are expected to call this from their ethtool_ops :: set_mm()
+ * method.
+ */
+void ethtool_mmsv_set_mm(struct ethtool_mmsv *mmsv, struct ethtool_mm_cfg *cfg);
+
+/**
+ * ethtool_mmsv_init() - Initialize MAC Merge Software Verification state
+ * @mmsv: MAC Merge Software Verification state
+ * @dev: Pointer to network interface
+ * @ops: Methods for implementing the generic functionality
+ *
+ * The MAC Merge Software Verification is a timer- and event-based state
+ * machine intended for network interfaces which lack a hardware-based
+ * TX verification process (as per IEEE 802.3 clause 99.4.3). The timer
+ * is managed by the core code, whereas events are supplied by the
+ * driver explicitly calling one of the other API functions.
+ */
+void ethtool_mmsv_init(struct ethtool_mmsv *mmsv, struct net_device *dev,
+		       const struct ethtool_mmsv_ops *ops);
+
 /**
  * struct ethtool_rxfh_param - RXFH (RSS) parameters
  * @hfunc: Defines the current RSS hash function used by HW (or to be set to).
diff --git a/net/ethtool/mm.c b/net/ethtool/mm.c
index 2816bb23c3ad..7b2a75f94800 100644
--- a/net/ethtool/mm.c
+++ b/net/ethtool/mm.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Copyright 2022-2023 NXP
+ * Copyright 2022-2025 NXP
+ * Copyright 2024 Furong Xu <0x1207@gmail.com>
  */
 #include "common.h"
 #include "netlink.h"
@@ -282,3 +283,225 @@ bool ethtool_dev_mm_supported(struct net_device *dev)
 	return supported;
 }
 EXPORT_SYMBOL_GPL(ethtool_dev_mm_supported);
+
+static void ethtool_mmsv_configure_tx(struct ethtool_mmsv *mmsv,
+				      bool tx_active)
+{
+	if (mmsv->ops->configure_tx)
+		mmsv->ops->configure_tx(mmsv, tx_active);
+}
+
+static void ethtool_mmsv_configure_pmac(struct ethtool_mmsv *mmsv,
+					bool pmac_enabled)
+{
+	if (mmsv->ops->configure_pmac)
+		mmsv->ops->configure_pmac(mmsv, pmac_enabled);
+}
+
+static void ethtool_mmsv_send_mpacket(struct ethtool_mmsv *mmsv,
+				      enum ethtool_mpacket mpacket)
+{
+	if (mmsv->ops->send_mpacket)
+		mmsv->ops->send_mpacket(mmsv, mpacket);
+}
+
+/**
+ * ethtool_mmsv_verify_timer - Timer for MAC Merge verification
+ * @t: timer_list struct containing private info
+ *
+ * Verify the MAC Merge capability in the local TX direction, by
+ * transmitting Verify mPackets up to 3 times. Wait until link
+ * partner responds with a Response mPacket, otherwise fail.
+ */
+static void ethtool_mmsv_verify_timer(struct timer_list *t)
+{
+	struct ethtool_mmsv *mmsv = from_timer(mmsv, t, verify_timer);
+	unsigned long flags;
+	bool rearm = false;
+
+	spin_lock_irqsave(&mmsv->lock, flags);
+
+	switch (mmsv->status) {
+	case ETHTOOL_MM_VERIFY_STATUS_INITIAL:
+	case ETHTOOL_MM_VERIFY_STATUS_VERIFYING:
+		if (mmsv->verify_retries != 0) {
+			ethtool_mmsv_send_mpacket(mmsv, ETHTOOL_MPACKET_VERIFY);
+			rearm = true;
+		} else {
+			mmsv->status = ETHTOOL_MM_VERIFY_STATUS_FAILED;
+		}
+
+		mmsv->verify_retries--;
+		break;
+
+	case ETHTOOL_MM_VERIFY_STATUS_SUCCEEDED:
+		ethtool_mmsv_configure_tx(mmsv, true);
+		break;
+
+	default:
+		break;
+	}
+
+	if (rearm) {
+		mod_timer(&mmsv->verify_timer,
+			  jiffies + msecs_to_jiffies(mmsv->verify_time));
+	}
+
+	spin_unlock_irqrestore(&mmsv->lock, flags);
+}
+
+static void ethtool_mmsv_verify_timer_arm(struct ethtool_mmsv *mmsv)
+{
+	if (mmsv->pmac_enabled && mmsv->tx_enabled && mmsv->verify_enabled &&
+	    mmsv->status != ETHTOOL_MM_VERIFY_STATUS_FAILED &&
+	    mmsv->status != ETHTOOL_MM_VERIFY_STATUS_SUCCEEDED) {
+		timer_setup(&mmsv->verify_timer, ethtool_mmsv_verify_timer, 0);
+		mod_timer(&mmsv->verify_timer, jiffies);
+	}
+}
+
+static void ethtool_mmsv_apply(struct ethtool_mmsv *mmsv)
+{
+	/* If verification is disabled, configure FPE right away.
+	 * Otherwise let the timer code do it.
+	 */
+	if (!mmsv->verify_enabled) {
+		ethtool_mmsv_configure_pmac(mmsv, mmsv->pmac_enabled);
+		ethtool_mmsv_configure_tx(mmsv, mmsv->tx_enabled);
+	} else {
+		mmsv->status = ETHTOOL_MM_VERIFY_STATUS_INITIAL;
+		mmsv->verify_retries = ETHTOOL_MM_MAX_VERIFY_RETRIES;
+
+		if (netif_running(mmsv->dev))
+			ethtool_mmsv_verify_timer_arm(mmsv);
+	}
+}
+
+void ethtool_mmsv_stop(struct ethtool_mmsv *mmsv)
+{
+	timer_shutdown_sync(&mmsv->verify_timer);
+}
+EXPORT_SYMBOL_GPL(ethtool_mmsv_stop);
+
+void ethtool_mmsv_link_state_handle(struct ethtool_mmsv *mmsv, bool up)
+{
+	unsigned long flags;
+
+	ethtool_mmsv_stop(mmsv);
+
+	spin_lock_irqsave(&mmsv->lock, flags);
+
+	if (up && mmsv->pmac_enabled) {
+		/* VERIFY process requires pMAC enabled when NIC comes up */
+		ethtool_mmsv_configure_pmac(mmsv, true);
+
+		/* New link => maybe new partner => new verification process */
+		ethtool_mmsv_apply(mmsv);
+	} else {
+		mmsv->status = ETHTOOL_MM_VERIFY_STATUS_INITIAL;
+		mmsv->verify_retries = ETHTOOL_MM_MAX_VERIFY_RETRIES;
+
+		/* No link or pMAC not enabled */
+		ethtool_mmsv_configure_pmac(mmsv, false);
+		ethtool_mmsv_configure_tx(mmsv, false);
+	}
+
+	spin_unlock_irqrestore(&mmsv->lock, flags);
+}
+EXPORT_SYMBOL_GPL(ethtool_mmsv_link_state_handle);
+
+void ethtool_mmsv_event_handle(struct ethtool_mmsv *mmsv,
+			       enum ethtool_mmsv_event event)
+{
+	/* This is interrupt context, just spin_lock() */
+	spin_lock(&mmsv->lock);
+
+	if (!mmsv->pmac_enabled)
+		goto unlock;
+
+	switch (event) {
+	case ETHTOOL_MMSV_LP_SENT_VERIFY_MPACKET:
+		/* Link partner has sent verify mPacket */
+		ethtool_mmsv_send_mpacket(mmsv, ETHTOOL_MPACKET_RESPONSE);
+		break;
+	case ETHTOOL_MMSV_LD_SENT_VERIFY_MPACKET:
+		/* Local device has sent verify mPacket */
+		if (mmsv->status != ETHTOOL_MM_VERIFY_STATUS_SUCCEEDED)
+			mmsv->status = ETHTOOL_MM_VERIFY_STATUS_VERIFYING;
+		break;
+	case ETHTOOL_MMSV_LP_SENT_RESPONSE_MPACKET:
+		/* Link partner has sent response mPacket */
+		if (mmsv->status == ETHTOOL_MM_VERIFY_STATUS_VERIFYING)
+			mmsv->status = ETHTOOL_MM_VERIFY_STATUS_SUCCEEDED;
+		break;
+	}
+
+unlock:
+	spin_unlock(&mmsv->lock);
+}
+EXPORT_SYMBOL_GPL(ethtool_mmsv_event_handle);
+
+static bool ethtool_mmsv_is_tx_active(struct ethtool_mmsv *mmsv)
+{
+	/* TX is active if administratively enabled, and verification either
+	 * succeeded, or was administratively disabled.
+	 */
+	return mmsv->tx_enabled &&
+	       (mmsv->status == ETHTOOL_MM_VERIFY_STATUS_SUCCEEDED ||
+	       mmsv->status == ETHTOOL_MM_VERIFY_STATUS_DISABLED);
+}
+
+void ethtool_mmsv_get_mm(struct ethtool_mmsv *mmsv,
+			 struct ethtool_mm_state *state)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&mmsv->lock, flags);
+
+	state->max_verify_time = ETHTOOL_MM_MAX_VERIFY_TIME_MS;
+	state->verify_enabled = mmsv->verify_enabled;
+	state->pmac_enabled = mmsv->pmac_enabled;
+	state->verify_time = mmsv->verify_time;
+	state->tx_enabled = mmsv->tx_enabled;
+	state->verify_status = mmsv->status;
+	state->tx_active = ethtool_mmsv_is_tx_active(mmsv);
+
+	spin_unlock_irqrestore(&mmsv->lock, flags);
+}
+EXPORT_SYMBOL_GPL(ethtool_mmsv_get_mm);
+
+void ethtool_mmsv_set_mm(struct ethtool_mmsv *mmsv, struct ethtool_mm_cfg *cfg)
+{
+	unsigned long flags;
+
+	/* Wait for the verification that's currently in progress to finish */
+	ethtool_mmsv_stop(mmsv);
+
+	spin_lock_irqsave(&mmsv->lock, flags);
+
+	mmsv->verify_enabled = cfg->verify_enabled;
+	mmsv->pmac_enabled = cfg->pmac_enabled;
+	mmsv->verify_time = cfg->verify_time;
+	mmsv->tx_enabled = cfg->tx_enabled;
+
+	if (!cfg->verify_enabled)
+		mmsv->status = ETHTOOL_MM_VERIFY_STATUS_DISABLED;
+
+	ethtool_mmsv_apply(mmsv);
+
+	spin_unlock_irqrestore(&mmsv->lock, flags);
+}
+EXPORT_SYMBOL_GPL(ethtool_mmsv_set_mm);
+
+void ethtool_mmsv_init(struct ethtool_mmsv *mmsv, struct net_device *dev,
+		       const struct ethtool_mmsv_ops *ops)
+{
+	mmsv->ops = ops;
+	mmsv->dev = dev;
+	mmsv->verify_retries = ETHTOOL_MM_MAX_VERIFY_RETRIES;
+	mmsv->verify_time = ETHTOOL_MM_MAX_VERIFY_TIME_MS;
+	mmsv->status = ETHTOOL_MM_VERIFY_STATUS_DISABLED;
+	timer_setup(&mmsv->verify_timer, ethtool_mmsv_verify_timer, 0);
+	spin_lock_init(&mmsv->lock);
+}
+EXPORT_SYMBOL_GPL(ethtool_mmsv_init);
-- 
2.34.1

Re: [PATCH iwl-next v5 1/9] net: ethtool: mm: extract stmmac verification logic into common library

[Vladimir Oltean]

On Wed, Feb 19, 2025 at 09:53:41PM -0500, Faizal Rahim wrote:
> +/**
> + * ethtool_mmsv_stop() - Stop MAC Merge Software Verification
> + * @mmsv: MAC Merge Software Verification state
> + *
> + * Drivers should call this method in a state where the hardware is
> + * about to lose state, like ndo_stop() or suspend(), and turning off
> + * MAC Merge features would be superfluous. Otherwise, prefer
> + * ethtool_mmsv_link_state_handle() with up=false.
> + */
> +void ethtool_mmsv_stop(struct ethtool_mmsv *mmsv);
> +
> +/**
> + * ethtool_mmsv_link_state_handle() - Inform MAC Merge Software Verification
> + *				      of link state changes
> + * @mmsv: MAC Merge Software Verification state
> + * @up: True if device carrier is up and able to pass verification packets
> + *
> + * Calling context is expected to be from a thread, interrupts enabled.

s/thread/task/, I think it's a more conventional way of referring to
process context.

> + */
> +void ethtool_mmsv_link_state_handle(struct ethtool_mmsv *mmsv, bool up);
> +
> +/**
> + * ethtool_mmsv_event_handle() - Inform MAC Merge Software Verification
> + *				 of interrupt-based events
> + * @mmsv: MAC Merge Software Verification state
> + * @event: Event which took place (packet transmission or reception)
> + *
> + * Calling context expects to have interrupts disabled.
> + */
> +void ethtool_mmsv_event_handle(struct ethtool_mmsv *mmsv,
> +			       enum ethtool_mmsv_event event);
> +
> +/**
> + * ethtool_mmsv_get_mm() - get_mm() hook for MAC Merge Software Verification
> + * @mmsv: MAC Merge Software Verification state
> + * @state: see struct ethtool_mm_state
> + *
> + * Drivers are expected to call this from their ethtool_ops :: get_mm()
> + * method.
> + */
> +void ethtool_mmsv_get_mm(struct ethtool_mmsv *mmsv,
> +			 struct ethtool_mm_state *state);
> +
> +/**
> + * ethtool_mmsv_set_mm() - set_mm() hook for MAC Merge Software Verification
> + * @mmsv: MAC Merge Software Verification state
> + * @cfg: see struct ethtool_mm_cfg
> + *
> + * Drivers are expected to call this from their ethtool_ops :: set_mm()
> + * method.
> + */
> +void ethtool_mmsv_set_mm(struct ethtool_mmsv *mmsv, struct ethtool_mm_cfg *cfg);
> +
> +/**
> + * ethtool_mmsv_init() - Initialize MAC Merge Software Verification state
> + * @mmsv: MAC Merge Software Verification state
> + * @dev: Pointer to network interface
> + * @ops: Methods for implementing the generic functionality
> + *
> + * The MAC Merge Software Verification is a timer- and event-based state
> + * machine intended for network interfaces which lack a hardware-based
> + * TX verification process (as per IEEE 802.3 clause 99.4.3). The timer
> + * is managed by the core code, whereas events are supplied by the
> + * driver explicitly calling one of the other API functions.
> + */
> +void ethtool_mmsv_init(struct ethtool_mmsv *mmsv, struct net_device *dev,
> +		       const struct ethtool_mmsv_ops *ops);

The kernel-doc comments are fine, but I think the convention is to
put them near the function definitions (in net/ethtool/mm.c) rather than
near the function prototypes, for the very simple reason that in the C
language, you can have multiple function declarations but a single definition.
The kernel-doc for the structures is fine where it is.

Re: [PATCH iwl-next v5 1/9] net: ethtool: mm: extract stmmac verification logic into common library

[Furong Xu]

On Wed, 19 Feb 2025 21:53:41 -0500, Faizal Rahim <faizal.abdul.rahim@linux.intel.com> wrote:

> From: Vladimir Oltean <vladimir.oltean@nxp.com>
> 
> It appears that stmmac is not the only hardware which requires a
> software-driven verification state machine for the MAC Merge layer.
> 
> While on the one hand it's good to encourage hardware implementations,
> on the other hand it's quite difficult to tolerate multiple drivers
> implementing independently fairly non-trivial logic.
> 
> Extract the hardware-independent logic from stmmac into library code and
> put it in ethtool. Name the state structure "mmsv" for MAC Merge
> Software Verification. Let this expose an operations structure for
> executing the hardware stuff: sync hardware with the tx_active boolean
> (result of verification process), enable/disable the pMAC, send mPackets,
> notify library of external events (reception of mPackets), as well as
> link state changes.
> 
> Note that it is assumed that the external events are received in hardirq
> context. If they are not, it is probably a good idea to disable hardirqs
> when calling ethtool_mmsv_event_handle(), because the library does not
> do so.
> 
> Also, the MM software verification process has no business with the
> tx_min_frag_size, that is all the driver's to handle.
> 
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> Co-developed-by: Choong Yong Liang <yong.liang.choong@linux.intel.com>
> Signed-off-by: Choong Yong Liang <yong.liang.choong@linux.intel.com>
> Co-developed-by: Faizal Rahim <faizal.abdul.rahim@linux.intel.com>
> Signed-off-by: Faizal Rahim <faizal.abdul.rahim@linux.intel.com>
> Tested-by: Choong Yong Liang <yong.liang.choong@linux.intel.com>
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac.h  |  16 +-
>  .../ethernet/stmicro/stmmac/stmmac_ethtool.c  |  41 +---
>  .../net/ethernet/stmicro/stmmac/stmmac_fpe.c  | 174 +++-----------
>  .../net/ethernet/stmicro/stmmac/stmmac_fpe.h  |   5 -
>  .../net/ethernet/stmicro/stmmac/stmmac_main.c |   8 +-
>  include/linux/ethtool.h                       | 131 ++++++++++
>  net/ethtool/mm.c                              | 225 +++++++++++++++++-
>  7 files changed, 399 insertions(+), 201 deletions(-)
> 
[...]
> +void ethtool_mmsv_link_state_handle(struct ethtool_mmsv *mmsv, bool up)
> +{
> +	unsigned long flags;
> +
> +	ethtool_mmsv_stop(mmsv);
> +
> +	spin_lock_irqsave(&mmsv->lock, flags);
> +
> +	if (up && mmsv->pmac_enabled) {
> +		/* VERIFY process requires pMAC enabled when NIC comes up */
> +		ethtool_mmsv_configure_pmac(mmsv, true);
> +
> +		/* New link => maybe new partner => new verification process */
> +		ethtool_mmsv_apply(mmsv);
> +	} else {
> +		mmsv->status = ETHTOOL_MM_VERIFY_STATUS_INITIAL;

Tested this patch on my side, everything works well, but the verify-status
is a little weird:

# kernel booted, check initial states:
ethtool --include-statistics --json --show-mm eth1
[ {
        "ifname": "eth1",
        "pmac-enabled": false,
        "tx-enabled": false,
        "tx-active": false,
        "tx-min-frag-size": 60,
        "rx-min-frag-size": 60,
        "verify-enabled": false,
        "verify-time": 128,
        "max-verify-time": 128,
        "verify-status": "INITIAL",
        "statistics": {
            "MACMergeFrameAssErrorCount": 0,
            "MACMergeFrameSmdErrorCount": 0,
            "MACMergeFrameAssOkCount": 0,
            "MACMergeFragCountRx": 0,
            "MACMergeFragCountTx": 0,
            "MACMergeHoldCount": 0
        }
    } ]

# Enable pMAC by: ethtool --set-mm eth1 pmac-enabled on
ethtool --include-statistics --json --show-mm eth1
[ {
        "ifname": "eth1",
        "pmac-enabled": true,
        "tx-enabled": false,
        "tx-active": false,
        "tx-min-frag-size": 60,
        "rx-min-frag-size": 60,
        "verify-enabled": false,
        "verify-time": 128,
        "max-verify-time": 128,
        "verify-status": "DISABLED",
        "statistics": {
            "MACMergeFrameAssErrorCount": 0,
            "MACMergeFrameSmdErrorCount": 0,
            "MACMergeFrameAssOkCount": 0,
            "MACMergeFragCountRx": 0,
            "MACMergeFragCountTx": 0,
            "MACMergeHoldCount": 0
        }
    } ]

# Disable pMAC by: ethtool --set-mm eth1 pmac-enabled off
ethtool --include-statistics --json --show-mm eth1
[ {
        "ifname": "eth1",
        "pmac-enabled": true,
        "tx-enabled": false,
        "tx-active": false,
        "tx-min-frag-size": 60,
        "rx-min-frag-size": 60,
        "verify-enabled": false,
        "verify-time": 128,
        "max-verify-time": 128,
        "verify-status": "DISABLED",
        "statistics": {
            "MACMergeFrameAssErrorCount": 0,
            "MACMergeFrameSmdErrorCount": 0,
            "MACMergeFrameAssOkCount": 0,
            "MACMergeFragCountRx": 0,
            "MACMergeFragCountTx": 0,
            "MACMergeHoldCount": 0
        }
    } ]

verify-status always normal on other cases.

@Vladimir, maybe we shouldn't update mmsv->status in ethtool_mmsv_link_state_handle()?
Or, update mmsv->status like below:
mmsv->status = mmsv->pmac_enabled ?
		ETHTOOL_MM_VERIFY_STATUS_INITIAL :
		ETHTOOL_MM_VERIFY_STATUS_DISABLED;

Anyway, this is too minor, so:

Tested-by: Furong Xu <0x1207@gmail.com>


> +		mmsv->verify_retries = ETHTOOL_MM_MAX_VERIFY_RETRIES;
> +
> +		/* No link or pMAC not enabled */
> +		ethtool_mmsv_configure_pmac(mmsv, false);
> +		ethtool_mmsv_configure_tx(mmsv, false);
> +	}
> +
> +	spin_unlock_irqrestore(&mmsv->lock, flags);
> +}
> +EXPORT_SYMBOL_GPL(ethtool_mmsv_link_state_handle);

Re: [PATCH iwl-next v5 1/9] net: ethtool: mm: extract stmmac verification logic into common library

[Vladimir Oltean]

On Fri, Feb 21, 2025 at 05:42:49PM +0800, Furong Xu wrote:
> > +void ethtool_mmsv_link_state_handle(struct ethtool_mmsv *mmsv, bool up)
> > +{
> > +	unsigned long flags;
> > +
> > +	ethtool_mmsv_stop(mmsv);
> > +
> > +	spin_lock_irqsave(&mmsv->lock, flags);
> > +
> > +	if (up && mmsv->pmac_enabled) {
> > +		/* VERIFY process requires pMAC enabled when NIC comes up */
> > +		ethtool_mmsv_configure_pmac(mmsv, true);
> > +
> > +		/* New link => maybe new partner => new verification process */
> > +		ethtool_mmsv_apply(mmsv);
> > +	} else {
> > +		mmsv->status = ETHTOOL_MM_VERIFY_STATUS_INITIAL;
> 
> Tested this patch on my side, everything works well, but the verify-status
> is a little weird:
> 
> # kernel booted, check initial states:
> ethtool --include-statistics --json --show-mm eth1
> [ {
>         "ifname": "eth1",
>         "pmac-enabled": false,
>         "tx-enabled": false,
>         "tx-active": false,
>         "tx-min-frag-size": 60,
>         "rx-min-frag-size": 60,
>         "verify-enabled": false,
>         "verify-time": 128,
>         "max-verify-time": 128,
>         "verify-status": "INITIAL",
>         "statistics": {
>             "MACMergeFrameAssErrorCount": 0,
>             "MACMergeFrameSmdErrorCount": 0,
>             "MACMergeFrameAssOkCount": 0,
>             "MACMergeFragCountRx": 0,
>             "MACMergeFragCountTx": 0,
>             "MACMergeHoldCount": 0
>         }
>     } ]
> 
> # Enable pMAC by: ethtool --set-mm eth1 pmac-enabled on
> ethtool --include-statistics --json --show-mm eth1
> [ {
>         "ifname": "eth1",
>         "pmac-enabled": true,
>         "tx-enabled": false,
>         "tx-active": false,
>         "tx-min-frag-size": 60,
>         "rx-min-frag-size": 60,
>         "verify-enabled": false,
>         "verify-time": 128,
>         "max-verify-time": 128,
>         "verify-status": "DISABLED",
>         "statistics": {
>             "MACMergeFrameAssErrorCount": 0,
>             "MACMergeFrameSmdErrorCount": 0,
>             "MACMergeFrameAssOkCount": 0,
>             "MACMergeFragCountRx": 0,
>             "MACMergeFragCountTx": 0,
>             "MACMergeHoldCount": 0
>         }
>     } ]
> 
> # Disable pMAC by: ethtool --set-mm eth1 pmac-enabled off
> ethtool --include-statistics --json --show-mm eth1
> [ {
>         "ifname": "eth1",
>         "pmac-enabled": true,
>         "tx-enabled": false,
>         "tx-active": false,
>         "tx-min-frag-size": 60,
>         "rx-min-frag-size": 60,
>         "verify-enabled": false,
>         "verify-time": 128,
>         "max-verify-time": 128,
>         "verify-status": "DISABLED",
>         "statistics": {
>             "MACMergeFrameAssErrorCount": 0,
>             "MACMergeFrameSmdErrorCount": 0,
>             "MACMergeFrameAssOkCount": 0,
>             "MACMergeFragCountRx": 0,
>             "MACMergeFragCountTx": 0,
>             "MACMergeHoldCount": 0
>         }
>     } ]
> 
> verify-status always normal on other cases.

Thanks for testing and for reporting this inconsistency.

> @Vladimir, maybe we shouldn't update mmsv->status in ethtool_mmsv_link_state_handle()?
> Or, update mmsv->status like below:
> mmsv->status = mmsv->pmac_enabled ?
> 		ETHTOOL_MM_VERIFY_STATUS_INITIAL :
> 		ETHTOOL_MM_VERIFY_STATUS_DISABLED;

You mean mmsv->status = mmsv->verify_enabled ? ETHTOOL_MM_VERIFY_STATUS_INITIAL :
                        ~~~~~~~~~~~~~~~~~~~~   ETHTOOL_MM_VERIFY_STATUS_DISABLED?

> Anyway, this is too minor, so:
> 
> Tested-by: Furong Xu <0x1207@gmail.com>
> 
> 
> > +		mmsv->verify_retries = ETHTOOL_MM_MAX_VERIFY_RETRIES;
> > +
> > +		/* No link or pMAC not enabled */
> > +		ethtool_mmsv_configure_pmac(mmsv, false);
> > +		ethtool_mmsv_configure_tx(mmsv, false);
> > +	}
> > +
> > +	spin_unlock_irqrestore(&mmsv->lock, flags);
> > +}
> > +EXPORT_SYMBOL_GPL(ethtool_mmsv_link_state_handle);

Re: [PATCH iwl-next v5 1/9] net: ethtool: mm: extract stmmac verification logic into common library

[Furong Xu]

On Fri, 21 Feb 2025 11:56:51 +0200, Vladimir Oltean <vladimir.oltean@nxp.com> wrote:

> On Fri, Feb 21, 2025 at 05:42:49PM +0800, Furong Xu wrote:
> > > +void ethtool_mmsv_link_state_handle(struct ethtool_mmsv *mmsv, bool up)
> > > +{
> > > +	unsigned long flags;
> > > +
> > > +	ethtool_mmsv_stop(mmsv);
> > > +
> > > +	spin_lock_irqsave(&mmsv->lock, flags);
> > > +
> > > +	if (up && mmsv->pmac_enabled) {
> > > +		/* VERIFY process requires pMAC enabled when NIC comes up */
> > > +		ethtool_mmsv_configure_pmac(mmsv, true);
> > > +
> > > +		/* New link => maybe new partner => new verification process */
> > > +		ethtool_mmsv_apply(mmsv);
> > > +	} else {
> > > +		mmsv->status = ETHTOOL_MM_VERIFY_STATUS_INITIAL;  
> > 
> > Tested this patch on my side, everything works well, but the verify-status
> > is a little weird:
> > 
> > # kernel booted, check initial states:
> > ethtool --include-statistics --json --show-mm eth1
> > [ {
> >         "ifname": "eth1",
> >         "pmac-enabled": false,
> >         "tx-enabled": false,
> >         "tx-active": false,
> >         "tx-min-frag-size": 60,
> >         "rx-min-frag-size": 60,
> >         "verify-enabled": false,
> >         "verify-time": 128,
> >         "max-verify-time": 128,
> >         "verify-status": "INITIAL",
> >         "statistics": {
> >             "MACMergeFrameAssErrorCount": 0,
> >             "MACMergeFrameSmdErrorCount": 0,
> >             "MACMergeFrameAssOkCount": 0,
> >             "MACMergeFragCountRx": 0,
> >             "MACMergeFragCountTx": 0,
> >             "MACMergeHoldCount": 0
> >         }
> >     } ]
> > 
> > # Enable pMAC by: ethtool --set-mm eth1 pmac-enabled on
> > ethtool --include-statistics --json --show-mm eth1
> > [ {
> >         "ifname": "eth1",
> >         "pmac-enabled": true,
> >         "tx-enabled": false,
> >         "tx-active": false,
> >         "tx-min-frag-size": 60,
> >         "rx-min-frag-size": 60,
> >         "verify-enabled": false,
> >         "verify-time": 128,
> >         "max-verify-time": 128,
> >         "verify-status": "DISABLED",
> >         "statistics": {
> >             "MACMergeFrameAssErrorCount": 0,
> >             "MACMergeFrameSmdErrorCount": 0,
> >             "MACMergeFrameAssOkCount": 0,
> >             "MACMergeFragCountRx": 0,
> >             "MACMergeFragCountTx": 0,
> >             "MACMergeHoldCount": 0
> >         }
> >     } ]
> > 
> > # Disable pMAC by: ethtool --set-mm eth1 pmac-enabled off
> > ethtool --include-statistics --json --show-mm eth1
> > [ {
> >         "ifname": "eth1",
> >         "pmac-enabled": true,
> >         "tx-enabled": false,
> >         "tx-active": false,
> >         "tx-min-frag-size": 60,
> >         "rx-min-frag-size": 60,
> >         "verify-enabled": false,
> >         "verify-time": 128,
> >         "max-verify-time": 128,
> >         "verify-status": "DISABLED",
> >         "statistics": {
> >             "MACMergeFrameAssErrorCount": 0,
> >             "MACMergeFrameSmdErrorCount": 0,
> >             "MACMergeFrameAssOkCount": 0,
> >             "MACMergeFragCountRx": 0,
> >             "MACMergeFragCountTx": 0,
> >             "MACMergeHoldCount": 0
> >         }
> >     } ]
> > 
> > verify-status always normal on other cases.  
> 
> Thanks for testing and for reporting this inconsistency.
> 
> > @Vladimir, maybe we shouldn't update mmsv->status in ethtool_mmsv_link_state_handle()?
> > Or, update mmsv->status like below:
> > mmsv->status = mmsv->pmac_enabled ?
> > 		ETHTOOL_MM_VERIFY_STATUS_INITIAL :
> > 		ETHTOOL_MM_VERIFY_STATUS_DISABLED;  
> 
> You mean mmsv->status = mmsv->verify_enabled ? ETHTOOL_MM_VERIFY_STATUS_INITIAL :
>                         ~~~~~~~~~~~~~~~~~~~~   ETHTOOL_MM_VERIFY_STATUS_DISABLED?

Your fix is better when link is up/down, so I vote verify_enabled.

Re: [PATCH iwl-next v5 1/9] net: ethtool: mm: extract stmmac verification logic into common library

[Vladimir Oltean]

On Fri, Feb 21, 2025 at 06:24:09PM +0800, Furong Xu wrote:
> Your fix is better when link is up/down, so I vote verify_enabled.

Hmmm... I thought this was a bug in stmmac that was carried over to
ethtool_mmsv, but it looks like it isn't.

In fact, looking at the original refactoring patch I had attached in
this email:
https://lore.kernel.org/netdev/20241217002254.lyakuia32jbnva46@skbuf/

these 2 lines in ethtool_mmsv_link_state_handle() didn't exist at all.

	} else {
>>>>		mmsv->status = ETHTOOL_MM_VERIFY_STATUS_INITIAL;
>>>>		mmsv->verify_retries = ETHTOOL_MM_MAX_VERIFY_RETRIES;

		/* No link or pMAC not enabled */
		ethtool_mmsv_configure_pmac(mmsv, false);
		ethtool_mmsv_configure_tx(mmsv, false);
	}

Faizal, could you remind me why they were added? I don't see this
explained in change logs.

Re: [PATCH iwl-next v5 1/9] net: ethtool: mm: extract stmmac verification logic into common library

[Abdul Rahim, Faizal]

On 21/2/2025 6:43 pm, Vladimir Oltean wrote:
> On Fri, Feb 21, 2025 at 06:24:09PM +0800, Furong Xu wrote:
>> Your fix is better when link is up/down, so I vote verify_enabled.
> 
> Hmmm... I thought this was a bug in stmmac that was carried over to
> ethtool_mmsv, but it looks like it isn't.
> 
> In fact, looking at the original refactoring patch I had attached in
> this email:
> https://lore.kernel.org/netdev/20241217002254.lyakuia32jbnva46@skbuf/
> 
> these 2 lines in ethtool_mmsv_link_state_handle() didn't exist at all.
> 
> 	} else {
>>>>> 		mmsv->status = ETHTOOL_MM_VERIFY_STATUS_INITIAL;
>>>>> 		mmsv->verify_retries = ETHTOOL_MM_MAX_VERIFY_RETRIES;
> 
> 		/* No link or pMAC not enabled */
> 		ethtool_mmsv_configure_pmac(mmsv, false);
> 		ethtool_mmsv_configure_tx(mmsv, false);
> 	}
> 
> Faizal, could you remind me why they were added? I don't see this
> explained in change logs.
> 

Hi Vladimir,

Yeah, it wasn’t there originally. I added that change because it failed the 
link down/link up test.
After a successful verification, if the link partner goes down, the status 
still shows ETHTOOL_MM_VERIFY_STATUS_SUCCEEDED, which isn’t correct—so 
that’s why I added it.

Sorry for not mentioning it earlier. I assumed you’d check the delta 
between the original patch and the upstream one, my bad, should have 
mentioned this logic change.

Should I update it to the latest suggestion?

Re: [PATCH iwl-next v5 1/9] net: ethtool: mm: extract stmmac verification logic into common library

[Vladimir Oltean]

On Fri, Feb 21, 2025 at 09:30:09PM +0800, Abdul Rahim, Faizal wrote:
> On 21/2/2025 6:43 pm, Vladimir Oltean wrote:
> > On Fri, Feb 21, 2025 at 06:24:09PM +0800, Furong Xu wrote:
> > > Your fix is better when link is up/down, so I vote verify_enabled.
> > 
> > Hmmm... I thought this was a bug in stmmac that was carried over to
> > ethtool_mmsv, but it looks like it isn't.
> > 
> > In fact, looking at the original refactoring patch I had attached in
> > this email:
> > https://lore.kernel.org/netdev/20241217002254.lyakuia32jbnva46@skbuf/
> > 
> > these 2 lines in ethtool_mmsv_link_state_handle() didn't exist at all.
> > 
> > 	} else {
> > > > > > 		mmsv->status = ETHTOOL_MM_VERIFY_STATUS_INITIAL;
> > > > > > 		mmsv->verify_retries = ETHTOOL_MM_MAX_VERIFY_RETRIES;
> > 
> > 		/* No link or pMAC not enabled */
> > 		ethtool_mmsv_configure_pmac(mmsv, false);
> > 		ethtool_mmsv_configure_tx(mmsv, false);
> > 	}
> > 
> > Faizal, could you remind me why they were added? I don't see this
> > explained in change logs.
> > 
> 
> Hi Vladimir,
> 
> Yeah, it wasn’t there originally. I added that change because it failed the
> link down/link up test.
> After a successful verification, if the link partner goes down, the status
> still shows ETHTOOL_MM_VERIFY_STATUS_SUCCEEDED, which isn’t correct—so
> that’s why I added it.
> 
> Sorry for not mentioning it earlier. I assumed you’d check the delta between
> the original patch and the upstream one, my bad, should have mentioned this
> logic change.
> 
> Should I update it to the latest suggestion?

Never, ever modify logic in the same commit as you are moving code.
I was wondering what's with the Co-developed-by: tags, but I had just
assumed fixups were made to code I had improperly moved because I
didn't have hardware to test. Always structure patches to be one single
logical change per patch, well justified and trivially correct.

I had assumed, in good faith, changes like this wouldn't sneak in, but I
guess thanks for letting me know I should check next time :)

I think it's a slightly open question which state should the verification
be in when the link fails, but in any case, your argument could be made
that the state of the previous verification should be lost.

If I look at figure 99-8 in the Verify state diagram, I see that
whenever the condition "begin || link_fail || disableVerify || !pEnable"
is true, we transition to the state INIT_VERIFICATION. From there, there
is a UCT (unconditional transition) to VERIFICATION_IDLE, and from there,
a transition to state SEND_VERIFY based on "pEnable && !disableVerify".
In principle what this is telling me is that as long as management
software doesn't set pEnable (tx_enable in Linux) to false, verification
would be attempted even with link down, and should eventually fail.

But the mmsv state machine does call ethtool_mmsv_configure_tx(mmsv, false),
and in that case, if I were to interpret the standard state machine very
strictly, it would remain blocked in state VERIFICATION_IDLE until a
link up (thus, we should report the state as "verifying").

But, to be honest, I think the existence of the VERIFICATION_IDLE state
doesn't make a lot of sense. The state machine should just transition on
"!link_fail && !disable_verify && pEnable" to SEND_VERIFY directly, and
from state WAIT_FOR_RESPONSE it should cycle back to SEND_VERIFY if the
verify timer expired but we still have retries, or to INIT_VERIFICATION
if link_fail, disableVerify or pEnable change. One more reason why I
believe the VERIFICATION_IDLE state is redundant and under-specified is
because it gives the user no chance to even _see_ the "initial" state
being reported ever, given the unconditional transition to VERIFICATION_IDLE.

So in that sense, I agree with your proposal, and in terms of code,
I would recommend just this:

 } else {
+	/* Reset the reported verification state while the link is down */
+	if (mmsv->verify_enabled)
+		mmsv->status = ETHTOOL_MM_VERIFY_STATUS_INITIAL;
 
 	/* No link or pMAC not enabled */
 	ethtool_mmsv_configure_pmac(mmsv, false);
 	ethtool_mmsv_configure_tx(mmsv, false);
 }

Because this is just for reporting to user space, resetting
"mmsv->verify_retries = ETHTOOL_MM_MAX_VERIFY_RETRIES;" doesn't matter,
we'll do it on link up anyway.

Also note that there's no ternary operator like in the discussion with
Furong. If mmsv->verify_enabled is false, the mmsv->status should
already be DISABLED, no need for us to re-assign it.

Re: [PATCH iwl-next v5 1/9] net: ethtool: mm: extract stmmac verification logic into common library

[Abdul Rahim, Faizal]

On 21/2/2025 10:44 pm, Vladimir Oltean wrote:
> On Fri, Feb 21, 2025 at 09:30:09PM +0800, Abdul Rahim, Faizal wrote:
>> On 21/2/2025 6:43 pm, Vladimir Oltean wrote:
>>> On Fri, Feb 21, 2025 at 06:24:09PM +0800, Furong Xu wrote:
>>>> Your fix is better when link is up/down, so I vote verify_enabled.
>>>
>>> Hmmm... I thought this was a bug in stmmac that was carried over to
>>> ethtool_mmsv, but it looks like it isn't.
>>>
>>> In fact, looking at the original refactoring patch I had attached in
>>> this email:
>>> https://lore.kernel.org/netdev/20241217002254.lyakuia32jbnva46@skbuf/
>>>
>>> these 2 lines in ethtool_mmsv_link_state_handle() didn't exist at all.
>>>
>>> 	} else {
>>>>>>> 		mmsv->status = ETHTOOL_MM_VERIFY_STATUS_INITIAL;
>>>>>>> 		mmsv->verify_retries = ETHTOOL_MM_MAX_VERIFY_RETRIES;
>>>
>>> 		/* No link or pMAC not enabled */
>>> 		ethtool_mmsv_configure_pmac(mmsv, false);
>>> 		ethtool_mmsv_configure_tx(mmsv, false);
>>> 	}
>>>
>>> Faizal, could you remind me why they were added? I don't see this
>>> explained in change logs.
>>>
>>
>> Hi Vladimir,
>>
>> Yeah, it wasn’t there originally. I added that change because it failed the
>> link down/link up test.
>> After a successful verification, if the link partner goes down, the status
>> still shows ETHTOOL_MM_VERIFY_STATUS_SUCCEEDED, which isn’t correct—so
>> that’s why I added it.
>>
>> Sorry for not mentioning it earlier. I assumed you’d check the delta between
>> the original patch and the upstream one, my bad, should have mentioned this
>> logic change.
>>
>> Should I update it to the latest suggestion?
> 
> Never, ever modify logic in the same commit as you are moving code.
> I was wondering what's with the Co-developed-by: tags, but I had just
> assumed fixups were made to code I had improperly moved because I
> didn't have hardware to test. Always structure patches to be one single
> logical change per patch, well justified and trivially correct.

Got it, sorry about that.

> I had assumed, in good faith, changes like this wouldn't sneak in, but I
> guess thanks for letting me know I should check next time :)
> 
> I think it's a slightly open question which state should the verification
> be in when the link fails, but in any case, your argument could be made
> that the state of the previous verification should be lost.
> 
> If I look at figure 99-8 in the Verify state diagram, I see that
> whenever the condition "begin || link_fail || disableVerify || !pEnable"
> is true, we transition to the state INIT_VERIFICATION. From there, there
> is a UCT (unconditional transition) to VERIFICATION_IDLE, and from there,
> a transition to state SEND_VERIFY based on "pEnable && !disableVerify".
> In principle what this is telling me is that as long as management
> software doesn't set pEnable (tx_enable in Linux) to false, verification
> would be attempted even with link down, and should eventually fail.
> 
> But the mmsv state machine does call ethtool_mmsv_configure_tx(mmsv, false),
> and in that case, if I were to interpret the standard state machine very
> strictly, it would remain blocked in state VERIFICATION_IDLE until a
> link up (thus, we should report the state as "verifying").
> 
> But, to be honest, I think the existence of the VERIFICATION_IDLE state
> doesn't make a lot of sense. The state machine should just transition on
> "!link_fail && !disable_verify && pEnable" to SEND_VERIFY directly, and
> from state WAIT_FOR_RESPONSE it should cycle back to SEND_VERIFY if the
> verify timer expired but we still have retries, or to INIT_VERIFICATION
> if link_fail, disableVerify or pEnable change. One more reason why I
> believe the VERIFICATION_IDLE state is redundant and under-specified is
> because it gives the user no chance to even _see_ the "initial" state
> being reported ever, given the unconditional transition to VERIFICATION_IDLE.
> 
> So in that sense, I agree with your proposal, and in terms of code,
> I would recommend just this:
> 
>   } else {
> +	/* Reset the reported verification state while the link is down */
> +	if (mmsv->verify_enabled)
> +		mmsv->status = ETHTOOL_MM_VERIFY_STATUS_INITIAL;
>   
>   	/* No link or pMAC not enabled */
>   	ethtool_mmsv_configure_pmac(mmsv, false);
>   	ethtool_mmsv_configure_tx(mmsv, false);
>   }
> 
> Because this is just for reporting to user space, resetting
> "mmsv->verify_retries = ETHTOOL_MM_MAX_VERIFY_RETRIES;" doesn't matter,
> we'll do it on link up anyway.
> 
> Also note that there's no ternary operator like in the discussion with
> Furong. If mmsv->verify_enabled is false, the mmsv->status should
> already be DISABLED, no need for us to re-assign it.
> 

Will update, thanks.

Re: [PATCH iwl-next v5 1/9] net: ethtool: mm: extract stmmac verification logic into common library

[Furong Xu]

On Wed, 19 Feb 2025 21:53:41 -0500, Faizal Rahim <faizal.abdul.rahim@linux.intel.com> wrote:

> @@ -1258,23 +1236,8 @@ static int stmmac_set_mm(struct net_device *ndev, struct ethtool_mm_cfg *cfg,
>  	if (err)
>  		return err;
>  
> -	/* Wait for the verification that's currently in progress to finish */
> -	timer_shutdown_sync(&fpe_cfg->verify_timer);
> -
> -	spin_lock_irqsave(&fpe_cfg->lock, flags);
> -
> -	fpe_cfg->verify_enabled = cfg->verify_enabled;
> -	fpe_cfg->pmac_enabled = cfg->pmac_enabled;
> -	fpe_cfg->verify_time = cfg->verify_time;
> -	fpe_cfg->tx_enabled = cfg->tx_enabled;
> -
> -	if (!cfg->verify_enabled)
> -		fpe_cfg->status = ETHTOOL_MM_VERIFY_STATUS_DISABLED;
> -
> +	ethtool_mmsv_set_mm(&priv->fpe_cfg.mmsv, cfg);
>  	stmmac_fpe_set_add_frag_size(priv, frag_size);
> -	stmmac_fpe_apply(priv);

Well, I would prefer keeping stmmac_fpe_set_add_frag_size() before
ethtool_mmsv_set_mm(), but not after, the VERIFY process should be
triggered after all the parameters are set.

> -
> -	spin_unlock_irqrestore(&fpe_cfg->lock, flags);
>  
>  	return 0;
>  }

[PATCH iwl-next v5 2/9] igc: Rename xdp_get_tx_ring() for non-xdp usage

[Faizal Rahim]

Renamed xdp_get_tx_ring() function to a more generic name for use in
upcoming frame preemption patches.

Signed-off-by: Faizal Rahim <faizal.abdul.rahim@linux.intel.com>
---
 drivers/net/ethernet/intel/igc/igc.h      |  2 +-
 drivers/net/ethernet/intel/igc/igc_main.c | 10 +++++-----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
index b8111ad9a9a8..22ecdac26cf4 100644
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -736,7 +736,7 @@ struct igc_nfc_rule *igc_get_nfc_rule(struct igc_adapter *adapter,
 				      u32 location);
 int igc_add_nfc_rule(struct igc_adapter *adapter, struct igc_nfc_rule *rule);
 void igc_del_nfc_rule(struct igc_adapter *adapter, struct igc_nfc_rule *rule);
-
+struct igc_ring *igc_get_tx_ring(struct igc_adapter *adapter, int cpu);
 void igc_ptp_init(struct igc_adapter *adapter);
 void igc_ptp_reset(struct igc_adapter *adapter);
 void igc_ptp_suspend(struct igc_adapter *adapter);
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 56a35d58e7a6..44e4f925491f 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -2444,8 +2444,8 @@ static int igc_xdp_init_tx_descriptor(struct igc_ring *ring,
 	return -ENOMEM;
 }
 
-static struct igc_ring *igc_xdp_get_tx_ring(struct igc_adapter *adapter,
-					    int cpu)
+struct igc_ring *igc_get_tx_ring(struct igc_adapter *adapter,
+				 int cpu)
 {
 	int index = cpu;
 
@@ -2469,7 +2469,7 @@ static int igc_xdp_xmit_back(struct igc_adapter *adapter, struct xdp_buff *xdp)
 	if (unlikely(!xdpf))
 		return -EFAULT;
 
-	ring = igc_xdp_get_tx_ring(adapter, cpu);
+	ring = igc_get_tx_ring(adapter, cpu);
 	nq = txring_txq(ring);
 
 	__netif_tx_lock(nq, cpu);
@@ -2546,7 +2546,7 @@ static void igc_finalize_xdp(struct igc_adapter *adapter, int status)
 	struct igc_ring *ring;
 
 	if (status & IGC_XDP_TX) {
-		ring = igc_xdp_get_tx_ring(adapter, cpu);
+		ring = igc_get_tx_ring(adapter, cpu);
 		nq = txring_txq(ring);
 
 		__netif_tx_lock(nq, cpu);
@@ -6699,7 +6699,7 @@ static int igc_xdp_xmit(struct net_device *dev, int num_frames,
 	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
 		return -EINVAL;
 
-	ring = igc_xdp_get_tx_ring(adapter, cpu);
+	ring = igc_get_tx_ring(adapter, cpu);
 	nq = txring_txq(ring);
 
 	__netif_tx_lock(nq, cpu);
-- 
2.34.1

[PATCH iwl-next v5 3/9] igc: Optimize the TX packet buffer utilization

[Faizal Rahim]

Packet buffers (RX + TX) total 64KB. Neither RX or TX buffers can be
larger than 34KB. So divide the buffer equally, 32KB for each.

Co-developed-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Faizal Rahim <faizal.abdul.rahim@linux.intel.com>
---
 drivers/net/ethernet/intel/igc/igc_defines.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_defines.h b/drivers/net/ethernet/intel/igc/igc_defines.h
index 8e449904aa7d..516ef70c98e9 100644
--- a/drivers/net/ethernet/intel/igc/igc_defines.h
+++ b/drivers/net/ethernet/intel/igc/igc_defines.h
@@ -400,7 +400,8 @@
 #define I225_TXPBSIZE_DEFAULT	0x04000014 /* TXPBSIZE default */
 #define IGC_RXPBS_CFG_TS_EN	0x80000000 /* Timestamp in Rx buffer */
 
-#define IGC_TXPBSIZE_TSN	0x04145145 /* 5k bytes buffer for each queue */
+ /* 7KB bytes buffer for each tx queue (total 4 queues) + 4KB for BMC*/
+#define IGC_TXPBSIZE_TSN	0x041c71c7
 
 #define IGC_DTXMXPKTSZ_TSN	0x19 /* 1600 bytes of max TX DMA packet size */
 #define IGC_DTXMXPKTSZ_DEFAULT	0x98 /* 9728-byte Jumbo frames */
-- 
2.34.1

[PATCH iwl-next v5 4/9] igc: Set the RX packet buffer size for TSN mode

[Faizal Rahim]

In preparation for supporting frame preemption, when entering TSN mode
set the receive packet buffer to 16KB for the Express MAC, 16KB for
the Preemptible MAC and 2KB for the BMC, according to the datasheet
section 7.1.3.2.

Co-developed-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Faizal Rahim <faizal.abdul.rahim@linux.intel.com>
---
 drivers/net/ethernet/intel/igc/igc_defines.h |  3 +++
 drivers/net/ethernet/intel/igc/igc_tsn.c     | 13 +++++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_defines.h b/drivers/net/ethernet/intel/igc/igc_defines.h
index 516ef70c98e9..b19ac6f30dac 100644
--- a/drivers/net/ethernet/intel/igc/igc_defines.h
+++ b/drivers/net/ethernet/intel/igc/igc_defines.h
@@ -402,6 +402,9 @@
 
  /* 7KB bytes buffer for each tx queue (total 4 queues) + 4KB for BMC*/
 #define IGC_TXPBSIZE_TSN	0x041c71c7
+/* 15KB for EXP + 15KB for BE + 2KB for BMC */
+#define IGC_RXPBSIZE_TSN	0x0000f08f
+#define IGC_RXPBSIZE_SIZE_MASK	0x0001FFFF
 
 #define IGC_DTXMXPKTSZ_TSN	0x19 /* 1600 bytes of max TX DMA packet size */
 #define IGC_DTXMXPKTSZ_DEFAULT	0x98 /* 9728-byte Jumbo frames */
diff --git a/drivers/net/ethernet/intel/igc/igc_tsn.c b/drivers/net/ethernet/intel/igc/igc_tsn.c
index 1e44374ca1ff..f0213cfce07d 100644
--- a/drivers/net/ethernet/intel/igc/igc_tsn.c
+++ b/drivers/net/ethernet/intel/igc/igc_tsn.c
@@ -132,13 +132,17 @@ static int igc_tsn_disable_offload(struct igc_adapter *adapter)
 {
 	u16 queue_per_tc[4] = { 3, 2, 1, 0 };
 	struct igc_hw *hw = &adapter->hw;
-	u32 tqavctrl;
+	u32 tqavctrl, rxpbs;
 	int i;
 
 	wr32(IGC_GTXOFFSET, 0);
 	wr32(IGC_TXPBS, I225_TXPBSIZE_DEFAULT);
 	wr32(IGC_DTXMXPKTSZ, IGC_DTXMXPKTSZ_DEFAULT);
 
+	rxpbs = rd32(IGC_RXPBS) & ~IGC_RXPBSIZE_SIZE_MASK;
+	rxpbs |= I225_RXPBSIZE_DEFAULT;
+	wr32(IGC_RXPBS, rxpbs);
+
 	if (igc_is_device_id_i226(hw))
 		igc_tsn_restore_retx_default(adapter);
 
@@ -194,7 +198,7 @@ static int igc_tsn_enable_offload(struct igc_adapter *adapter)
 {
 	struct igc_hw *hw = &adapter->hw;
 	u32 tqavctrl, baset_l, baset_h;
-	u32 sec, nsec, cycle;
+	u32 sec, nsec, cycle, rxpbs;
 	ktime_t base_time, systim;
 	int i;
 
@@ -202,6 +206,11 @@ static int igc_tsn_enable_offload(struct igc_adapter *adapter)
 	wr32(IGC_DTXMXPKTSZ, IGC_DTXMXPKTSZ_TSN);
 	wr32(IGC_TXPBS, IGC_TXPBSIZE_TSN);
 
+	rxpbs = rd32(IGC_RXPBS) & ~IGC_RXPBSIZE_SIZE_MASK;
+	rxpbs |= IGC_RXPBSIZE_TSN;
+
+	wr32(IGC_RXPBS, rxpbs);
+
 	if (igc_is_device_id_i226(hw))
 		igc_tsn_set_retx_qbvfullthreshold(adapter);
 
-- 
2.34.1

[PATCH iwl-next v5 5/9] igc: Add support for frame preemption verification

[Faizal Rahim]

This patch implements the "ethtool --set-mm" callback to trigger the
frame preemption verification handshake.

Uses the MAC Merge Software Verification (mmsv) mechanism in ethtool
to perform the verification handshake for igc.
The structure fpe.mmsv is set by mmsv in ethtool and should remain
read-only for the driver.

Other mmsv callbacks:
a) configure_tx() -> not used yet at this point
   - igc lacks registers to configure FPE in the transmit direction, so
     this API is not utilized for now. A future patch will use it to
     control preemptible queue config.

b) configure_pmac() -> not used
   - this callback dynamically controls pmac_enabled at runtime. For
     example, mmsv calls configure_pmac() and disables pmac_enabled when
     the link partner goes down, even if the user previously enabled it.
     The intention is to save power but it is not feasible in igc
     because it causes an endless adapter reset loop:

   1) Board A and Board B complete the verification handshake. Tx mode
      register for both boards are in TSN mode.
   2) Board B link goes down.

   On Board A:
   3) mmsv calls configure_pmac() with pmac_enabled = false.
   4) configure_pmac() in igc updates a new field based on pmac_enabled.
      Driver uses this field in igc_tsn_new_flags() to indicate that the
      user enabled/disabled FPE.
   5) configure_pmac() in igc calls igc_tsn_offload_apply() to check
      whether an adapter reset is needed. Calls existing logic in
      igc_tsn_will_tx_mode_change() and igc_tsn_new_flags().
   6) Since pmac_enabled is now disabled and no other TSN feature is
      active, igc_tsn_will_tx_mode_change() evaluates to true because Tx
      mode will switch from TSN to Legacy.
   7) Driver resets the adapter.
   8) Registers are set, and Tx mode switches to Legacy.
   9) When link partner is up, steps 3–8 repeat, but this time with
      pmac_enabled = true, reactivating TSN.
      igc_tsn_will_tx_mode_change() evaluates to true again, since Tx
      mode will switch from Legacy to TSN.
  10) Driver resets the adapter.
  11) Rest adapter completes, registers are set, and Tx mode switches to
      TSN.

  On Board B:
  12) Adapter reset on Board A at step 10 causes it to detect its link
      partner as down.
  13) Repeats steps 3–8.
  14) Once reset adapter on Board A is completed at step 11, it detects
      its link partner as up.
  15) Repeats steps 9–11.

   - this cycle repeats indefinitely. To avoid this issue, igc only uses
     mmsv.pmac_enabled to track whether FPE is enabled or disabled.

Co-developed-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Co-developed-by: Choong Yong Liang <yong.liang.choong@linux.intel.com>
Signed-off-by: Choong Yong Liang <yong.liang.choong@linux.intel.com>
Signed-off-by: Faizal Rahim <faizal.abdul.rahim@linux.intel.com>
---
 drivers/net/ethernet/intel/igc/igc.h         |  12 +-
 drivers/net/ethernet/intel/igc/igc_base.h    |   1 +
 drivers/net/ethernet/intel/igc/igc_defines.h |   8 +-
 drivers/net/ethernet/intel/igc/igc_ethtool.c |  21 +++
 drivers/net/ethernet/intel/igc/igc_main.c    |  53 ++++++-
 drivers/net/ethernet/intel/igc/igc_tsn.c     | 144 ++++++++++++++++++-
 drivers/net/ethernet/intel/igc/igc_tsn.h     |  51 +++++++
 7 files changed, 285 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
index 22ecdac26cf4..705bd4739e3b 100644
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -40,6 +40,10 @@ void igc_ethtool_set_ops(struct net_device *);
 
 #define IGC_MAX_TX_TSTAMP_REGS		4
 
+struct fpe_t {
+	struct ethtool_mmsv mmsv;
+};
+
 enum igc_mac_filter_type {
 	IGC_MAC_FILTER_TYPE_DST = 0,
 	IGC_MAC_FILTER_TYPE_SRC
@@ -332,6 +336,8 @@ struct igc_adapter {
 		struct timespec64 period;
 	} perout[IGC_N_PEROUT];
 
+	struct fpe_t fpe;
+
 	/* LEDs */
 	struct mutex led_mutex;
 	struct igc_led_classdev *leds;
@@ -389,10 +395,11 @@ extern char igc_driver_name[];
 #define IGC_FLAG_TSN_QBV_ENABLED	BIT(17)
 #define IGC_FLAG_TSN_QAV_ENABLED	BIT(18)
 #define IGC_FLAG_TSN_LEGACY_ENABLED	BIT(19)
+#define IGC_FLAG_TSN_PREEMPT_ENABLED	BIT(20)
 
 #define IGC_FLAG_TSN_ANY_ENABLED				\
 	(IGC_FLAG_TSN_QBV_ENABLED | IGC_FLAG_TSN_QAV_ENABLED |	\
-	 IGC_FLAG_TSN_LEGACY_ENABLED)
+	 IGC_FLAG_TSN_LEGACY_ENABLED | IGC_FLAG_TSN_PREEMPT_ENABLED)
 
 #define IGC_FLAG_RSS_FIELD_IPV4_UDP	BIT(6)
 #define IGC_FLAG_RSS_FIELD_IPV6_UDP	BIT(7)
@@ -736,7 +743,10 @@ struct igc_nfc_rule *igc_get_nfc_rule(struct igc_adapter *adapter,
 				      u32 location);
 int igc_add_nfc_rule(struct igc_adapter *adapter, struct igc_nfc_rule *rule);
 void igc_del_nfc_rule(struct igc_adapter *adapter, struct igc_nfc_rule *rule);
+void igc_disable_empty_addr_recv(struct igc_adapter *adapter);
+int igc_enable_empty_addr_recv(struct igc_adapter *adapter);
 struct igc_ring *igc_get_tx_ring(struct igc_adapter *adapter, int cpu);
+void igc_flush_tx_descriptors(struct igc_ring *ring);
 void igc_ptp_init(struct igc_adapter *adapter);
 void igc_ptp_reset(struct igc_adapter *adapter);
 void igc_ptp_suspend(struct igc_adapter *adapter);
diff --git a/drivers/net/ethernet/intel/igc/igc_base.h b/drivers/net/ethernet/intel/igc/igc_base.h
index bf8cdfbba9ff..6320eabb72fe 100644
--- a/drivers/net/ethernet/intel/igc/igc_base.h
+++ b/drivers/net/ethernet/intel/igc/igc_base.h
@@ -49,6 +49,7 @@ struct igc_adv_tx_context_desc {
 #define IGC_ADVTXD_DCMD_DEXT	0x20000000 /* Descriptor extension (1=Adv) */
 #define IGC_ADVTXD_DCMD_VLE	0x40000000 /* VLAN pkt enable */
 #define IGC_ADVTXD_DCMD_TSE	0x80000000 /* TCP Seg enable */
+#define IGC_ADVTXD_PAYLEN_MASK	0XFFFFC000 /* Adv desc PAYLEN mask */
 #define IGC_ADVTXD_PAYLEN_SHIFT	14 /* Adv desc PAYLEN shift */
 
 #define IGC_RAR_ENTRIES		16
diff --git a/drivers/net/ethernet/intel/igc/igc_defines.h b/drivers/net/ethernet/intel/igc/igc_defines.h
index b19ac6f30dac..22db1de02964 100644
--- a/drivers/net/ethernet/intel/igc/igc_defines.h
+++ b/drivers/net/ethernet/intel/igc/igc_defines.h
@@ -308,6 +308,8 @@
 #define IGC_TXD_DTYP_C		0x00000000 /* Context Descriptor */
 #define IGC_TXD_POPTS_IXSM	0x01       /* Insert IP checksum */
 #define IGC_TXD_POPTS_TXSM	0x02       /* Insert TCP/UDP checksum */
+#define IGC_TXD_POPTS_SMD_MASK	0x3000     /* Indicates whether it's SMD-V or SMD-R */
+
 #define IGC_TXD_CMD_EOP		0x01000000 /* End of Packet */
 #define IGC_TXD_CMD_IC		0x04000000 /* Insert Checksum */
 #define IGC_TXD_CMD_DEXT	0x20000000 /* Desc extension (0 = legacy) */
@@ -363,6 +365,8 @@
 #define IGC_SRRCTL_TIMER0SEL(timer)	(((timer) & 0x3) << 17)
 
 /* Receive Descriptor bit definitions */
+#define IGC_RXD_STAT_SMD_TYPE_V	0x01	/* SMD-V Packet */
+#define IGC_RXD_STAT_SMD_TYPE_R	0x02	/* SMD-R Packet */
 #define IGC_RXD_STAT_EOP	0x02	/* End of Packet */
 #define IGC_RXD_STAT_IXSM	0x04	/* Ignore checksum */
 #define IGC_RXD_STAT_UDPCS	0x10	/* UDP xsum calculated */
@@ -372,7 +376,8 @@
 #define IGC_RXDEXT_STATERR_LB	0x00040000
 
 /* Advanced Receive Descriptor bit definitions */
-#define IGC_RXDADV_STAT_TSIP	0x08000 /* timestamp in packet */
+#define IGC_RXDADV_STAT_SMD_TYPE_MASK	0x06000
+#define IGC_RXDADV_STAT_TSIP		0x08000 /* timestamp in packet */
 
 #define IGC_RXDEXT_STATERR_L4E		0x20000000
 #define IGC_RXDEXT_STATERR_IPE		0x40000000
@@ -543,6 +548,7 @@
 
 /* Transmit Scheduling */
 #define IGC_TQAVCTRL_TRANSMIT_MODE_TSN	0x00000001
+#define IGC_TQAVCTRL_PREEMPT_ENA	0x00000002
 #define IGC_TQAVCTRL_ENHANCED_QAV	0x00000008
 #define IGC_TQAVCTRL_FUTSCDDIS		0x00000080
 
diff --git a/drivers/net/ethernet/intel/igc/igc_ethtool.c b/drivers/net/ethernet/intel/igc/igc_ethtool.c
index 817838677817..e2a14edf7552 100644
--- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
+++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
@@ -8,6 +8,7 @@
 
 #include "igc.h"
 #include "igc_diag.h"
+#include "igc_tsn.h"
 
 /* forward declaration */
 struct igc_stats {
@@ -1781,6 +1782,25 @@ static int igc_ethtool_set_eee(struct net_device *netdev,
 	return 0;
 }
 
+static int igc_ethtool_set_mm(struct net_device *netdev,
+			      struct ethtool_mm_cfg *cmd,
+			      struct netlink_ext_ack *extack)
+{
+	struct igc_adapter *adapter = netdev_priv(netdev);
+	struct fpe_t *fpe = &adapter->fpe;
+
+	if (fpe->mmsv.pmac_enabled != cmd->pmac_enabled) {
+		if (cmd->pmac_enabled)
+			static_branch_inc(&igc_fpe_enabled);
+		else
+			static_branch_dec(&igc_fpe_enabled);
+	}
+
+	ethtool_mmsv_set_mm(&fpe->mmsv, cmd);
+
+	return igc_tsn_offload_apply(adapter);
+}
+
 static int igc_ethtool_get_link_ksettings(struct net_device *netdev,
 					  struct ethtool_link_ksettings *cmd)
 {
@@ -2068,6 +2088,7 @@ static const struct ethtool_ops igc_ethtool_ops = {
 	.set_rxfh		= igc_ethtool_set_rxfh,
 	.get_ts_info		= igc_ethtool_get_ts_info,
 	.get_channels		= igc_ethtool_get_channels,
+	.set_mm			= igc_ethtool_set_mm,
 	.set_channels		= igc_ethtool_set_channels,
 	.get_priv_flags		= igc_ethtool_get_priv_flags,
 	.set_priv_flags		= igc_ethtool_set_priv_flags,
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 44e4f925491f..5a6648a12a53 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -2529,7 +2529,7 @@ static int igc_xdp_run_prog(struct igc_adapter *adapter, struct xdp_buff *xdp)
 }
 
 /* This function assumes __netif_tx_lock is held by the caller. */
-static void igc_flush_tx_descriptors(struct igc_ring *ring)
+void igc_flush_tx_descriptors(struct igc_ring *ring)
 {
 	/* Once tail pointer is updated, hardware can fetch the descriptors
 	 * any time so we issue a write membar here to ensure all memory
@@ -2618,6 +2618,15 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
 			size -= IGC_TS_HDR_LEN;
 		}
 
+		if (igc_fpe_is_pmac_enabled(adapter) &&
+		    igc_fpe_is_verify_or_response(rx_desc, size)) {
+			igc_fpe_lp_event_status(rx_desc, &adapter->fpe.mmsv);
+			/* Advance the ring next-to-clean */
+			igc_is_non_eop(rx_ring, rx_desc);
+			cleaned_count++;
+			continue;
+		}
+
 		if (!skb) {
 			xdp_init_buff(&ctx.xdp, truesize, &rx_ring->xdp_rxq);
 			xdp_prepare_buff(&ctx.xdp, pktbuf - igc_rx_offset(rx_ring),
@@ -3065,6 +3074,11 @@ static bool igc_clean_tx_irq(struct igc_q_vector *q_vector, int napi_budget)
 		if (!(eop_desc->wb.status & cpu_to_le32(IGC_TXD_STAT_DD)))
 			break;
 
+		if (igc_fpe_is_pmac_enabled(adapter) &&
+		    igc_fpe_transmitted_smd_v(tx_desc))
+			ethtool_mmsv_event_handle(&adapter->fpe.mmsv,
+						  ETHTOOL_MMSV_LD_SENT_VERIFY_MPACKET);
+
 		/* Hold the completions while there's a pending tx hardware
 		 * timestamp request from XDP Tx metadata.
 		 */
@@ -3956,6 +3970,30 @@ static int igc_uc_unsync(struct net_device *netdev, const unsigned char *addr)
 	return 0;
 }
 
+/**
+ * igc_enable_empty_addr_recv - Enable rx of packets with all-zeroes MAC address
+ * @adapter: Pointer to the igc_adapter structure.
+ *
+ * Frame preemption verification requires that packets with the all-zeroes
+ * MAC address are allowed to be received by IGC. This function adds the
+ * all-zeroes destination address to the list of acceptable addresses.
+ *
+ * Return: 0 on success, negative value otherwise.
+ */
+int igc_enable_empty_addr_recv(struct igc_adapter *adapter)
+{
+	u8 empty[ETH_ALEN] = { };
+
+	return igc_add_mac_filter(adapter, IGC_MAC_FILTER_TYPE_DST, empty, -1);
+}
+
+void igc_disable_empty_addr_recv(struct igc_adapter *adapter)
+{
+	u8 empty[ETH_ALEN] = { };
+
+	igc_del_mac_filter(adapter, IGC_MAC_FILTER_TYPE_DST, empty);
+}
+
 /**
  * igc_set_rx_mode - Secondary Unicast, Multicast and Promiscuous mode set
  * @netdev: network interface device structure
@@ -5231,6 +5269,9 @@ void igc_down(struct igc_adapter *adapter)
 	igc_disable_all_tx_rings_hw(adapter);
 	igc_clean_all_tx_rings(adapter);
 	igc_clean_all_rx_rings(adapter);
+
+	if (adapter->fpe.mmsv.pmac_enabled)
+		ethtool_mmsv_stop(&adapter->fpe.mmsv);
 }
 
 void igc_reinit_locked(struct igc_adapter *adapter)
@@ -5755,6 +5796,10 @@ static void igc_watchdog_task(struct work_struct *work)
 			 */
 			igc_tsn_adjust_txtime_offset(adapter);
 
+			if (adapter->fpe.mmsv.pmac_enabled)
+				ethtool_mmsv_link_state_handle(&adapter->fpe.mmsv,
+							       true);
+
 			if (adapter->link_speed != SPEED_1000)
 				goto no_wait;
 
@@ -5790,6 +5835,10 @@ static void igc_watchdog_task(struct work_struct *work)
 			netdev_info(netdev, "NIC Link is Down\n");
 			netif_carrier_off(netdev);
 
+			if (adapter->fpe.mmsv.pmac_enabled)
+				ethtool_mmsv_link_state_handle(&adapter->fpe.mmsv,
+							       false);
+
 			/* link state has changed, schedule phy info update */
 			if (!test_bit(__IGC_DOWN, &adapter->state))
 				mod_timer(&adapter->phy_info_timer,
@@ -7110,6 +7159,8 @@ static int igc_probe(struct pci_dev *pdev,
 
 	igc_tsn_clear_schedule(adapter);
 
+	igc_fpe_init(adapter);
+
 	/* reset the hardware with the new settings */
 	igc_reset(adapter);
 
diff --git a/drivers/net/ethernet/intel/igc/igc_tsn.c b/drivers/net/ethernet/intel/igc/igc_tsn.c
index f0213cfce07d..fbe3e70d8ea9 100644
--- a/drivers/net/ethernet/intel/igc/igc_tsn.c
+++ b/drivers/net/ethernet/intel/igc/igc_tsn.c
@@ -1,10 +1,137 @@
 // SPDX-License-Identifier: GPL-2.0
 /* Copyright (c)  2019 Intel Corporation */
 
+#include <linux/kernel.h>
 #include "igc.h"
+#include "igc_base.h"
 #include "igc_hw.h"
 #include "igc_tsn.h"
 
+DEFINE_STATIC_KEY_FALSE(igc_fpe_enabled);
+
+static int igc_fpe_init_smd_frame(struct igc_ring *ring,
+				  struct igc_tx_buffer *buffer,
+				  struct sk_buff *skb)
+{
+	dma_addr_t dma = dma_map_single(ring->dev, skb->data, skb->len,
+					DMA_TO_DEVICE);
+
+	if (dma_mapping_error(ring->dev, dma)) {
+		netdev_err_once(ring->netdev, "Failed to map DMA for TX\n");
+		return -ENOMEM;
+	}
+
+	buffer->skb = skb;
+	buffer->protocol = 0;
+	buffer->bytecount = skb->len;
+	buffer->gso_segs = 1;
+	buffer->time_stamp = jiffies;
+	dma_unmap_len_set(buffer, len, skb->len);
+	dma_unmap_addr_set(buffer, dma, dma);
+
+	return 0;
+}
+
+static int igc_fpe_init_tx_descriptor(struct igc_ring *ring,
+				      struct sk_buff *skb,
+				      enum igc_txd_popts_type type)
+{
+	u32 cmd_type, olinfo_status = 0;
+	struct igc_tx_buffer *buffer;
+	union igc_adv_tx_desc *desc;
+	int err;
+
+	if (!igc_desc_unused(ring))
+		return -EBUSY;
+
+	buffer = &ring->tx_buffer_info[ring->next_to_use];
+	err = igc_fpe_init_smd_frame(ring, buffer, skb);
+	if (err)
+		return err;
+
+	cmd_type = IGC_ADVTXD_DTYP_DATA | IGC_ADVTXD_DCMD_DEXT |
+		   IGC_ADVTXD_DCMD_IFCS | IGC_TXD_DCMD |
+		   buffer->bytecount;
+
+	olinfo_status |= FIELD_PREP(IGC_ADVTXD_PAYLEN_MASK, buffer->bytecount);
+
+	switch (type) {
+	case SMD_V:
+	case SMD_R:
+		olinfo_status |= FIELD_PREP(IGC_TXD_POPTS_SMD_MASK, type);
+		break;
+	}
+
+	desc = IGC_TX_DESC(ring, ring->next_to_use);
+	desc->read.cmd_type_len = cpu_to_le32(cmd_type);
+	desc->read.olinfo_status = cpu_to_le32(olinfo_status);
+	desc->read.buffer_addr = cpu_to_le64(dma_unmap_addr(buffer, dma));
+
+	netdev_tx_sent_queue(txring_txq(ring), skb->len);
+
+	buffer->next_to_watch = desc;
+	ring->next_to_use = (ring->next_to_use + 1) % ring->count;
+
+	return 0;
+}
+
+static int igc_fpe_xmit_smd_frame(struct igc_adapter *adapter,
+				  enum igc_txd_popts_type type)
+{
+	int cpu = smp_processor_id();
+	struct netdev_queue *nq;
+	struct igc_ring *ring;
+	struct sk_buff *skb;
+	int err;
+
+	ring = igc_get_tx_ring(adapter, cpu);
+	nq = txring_txq(ring);
+
+	skb = alloc_skb(SMD_FRAME_SIZE, GFP_KERNEL);
+	if (!skb)
+		return -ENOMEM;
+
+	skb_put_zero(skb, SMD_FRAME_SIZE);
+
+	__netif_tx_lock(nq, cpu);
+
+	err = igc_fpe_init_tx_descriptor(ring, skb, type);
+	igc_flush_tx_descriptors(ring);
+
+	__netif_tx_unlock(nq);
+
+	return err;
+}
+
+static void igc_fpe_send_mpacket(struct ethtool_mmsv *mmsv,
+				 enum ethtool_mpacket type)
+{
+	struct fpe_t *fpe = container_of(mmsv, struct fpe_t, mmsv);
+	struct igc_adapter *adapter;
+	int err;
+
+	adapter = container_of(fpe, struct igc_adapter, fpe);
+
+	if (type == ETHTOOL_MPACKET_VERIFY) {
+		err = igc_fpe_xmit_smd_frame(adapter, SMD_V);
+		if (err && net_ratelimit())
+			netdev_err(adapter->netdev, "Error sending SMD-V\n");
+	} else if (type == ETHTOOL_MPACKET_RESPONSE) {
+		err = igc_fpe_xmit_smd_frame(adapter, SMD_R);
+		if (err && net_ratelimit())
+			netdev_err(adapter->netdev, "Error sending SMD-R frame\n");
+	}
+}
+
+static const struct ethtool_mmsv_ops igc_mmsv_ops = {
+	.send_mpacket = igc_fpe_send_mpacket,
+};
+
+void igc_fpe_init(struct igc_adapter *adapter)
+{
+	ethtool_mmsv_init(&adapter->fpe.mmsv, adapter->netdev, &igc_mmsv_ops);
+}
+
 static bool is_any_launchtime(struct igc_adapter *adapter)
 {
 	int i;
@@ -49,6 +176,9 @@ static unsigned int igc_tsn_new_flags(struct igc_adapter *adapter)
 	if (adapter->strict_priority_enable)
 		new_flags |= IGC_FLAG_TSN_LEGACY_ENABLED;
 
+	if (adapter->fpe.mmsv.pmac_enabled)
+		new_flags |= IGC_FLAG_TSN_PREEMPT_ENABLED;
+
 	return new_flags;
 }
 
@@ -148,7 +278,8 @@ static int igc_tsn_disable_offload(struct igc_adapter *adapter)
 
 	tqavctrl = rd32(IGC_TQAVCTRL);
 	tqavctrl &= ~(IGC_TQAVCTRL_TRANSMIT_MODE_TSN |
-		      IGC_TQAVCTRL_ENHANCED_QAV | IGC_TQAVCTRL_FUTSCDDIS);
+		      IGC_TQAVCTRL_ENHANCED_QAV | IGC_TQAVCTRL_FUTSCDDIS |
+		      IGC_TQAVCTRL_PREEMPT_ENA);
 
 	wr32(IGC_TQAVCTRL, tqavctrl);
 
@@ -370,10 +501,14 @@ static int igc_tsn_enable_offload(struct igc_adapter *adapter)
 		wr32(IGC_TXQCTL(i), txqctl);
 	}
 
-	tqavctrl = rd32(IGC_TQAVCTRL) & ~IGC_TQAVCTRL_FUTSCDDIS;
+	tqavctrl = rd32(IGC_TQAVCTRL) & ~(IGC_TQAVCTRL_FUTSCDDIS |
+		   IGC_TQAVCTRL_PREEMPT_ENA);
 
 	tqavctrl |= IGC_TQAVCTRL_TRANSMIT_MODE_TSN | IGC_TQAVCTRL_ENHANCED_QAV;
 
+	if (adapter->fpe.mmsv.pmac_enabled)
+		tqavctrl |= IGC_TQAVCTRL_PREEMPT_ENA;
+
 	adapter->qbv_count++;
 
 	cycle = adapter->cycle_time;
@@ -434,6 +569,11 @@ int igc_tsn_reset(struct igc_adapter *adapter)
 	unsigned int new_flags;
 	int err = 0;
 
+	if (adapter->fpe.mmsv.pmac_enabled)
+		igc_enable_empty_addr_recv(adapter);
+	else
+		igc_disable_empty_addr_recv(adapter);
+
 	new_flags = igc_tsn_new_flags(adapter);
 
 	if (!(new_flags & IGC_FLAG_TSN_ANY_ENABLED))
diff --git a/drivers/net/ethernet/intel/igc/igc_tsn.h b/drivers/net/ethernet/intel/igc/igc_tsn.h
index 98ec845a86bf..7ba232ef37c9 100644
--- a/drivers/net/ethernet/intel/igc/igc_tsn.h
+++ b/drivers/net/ethernet/intel/igc/igc_tsn.h
@@ -4,9 +4,60 @@
 #ifndef _IGC_TSN_H_
 #define _IGC_TSN_H_
 
+#define SMD_FRAME_SIZE			60
+
+enum igc_txd_popts_type {
+	SMD_V = 0x01,
+	SMD_R = 0x02
+};
+
+DECLARE_STATIC_KEY_FALSE(igc_fpe_enabled);
+
+void igc_fpe_init(struct igc_adapter *adapter);
+u32 igc_fpe_get_supported_frag_size(u32 user_frag_size);
 int igc_tsn_offload_apply(struct igc_adapter *adapter);
 int igc_tsn_reset(struct igc_adapter *adapter);
 void igc_tsn_adjust_txtime_offset(struct igc_adapter *adapter);
 bool igc_tsn_is_taprio_activated_by_user(struct igc_adapter *adapter);
 
+static inline bool igc_fpe_is_pmac_enabled(struct igc_adapter *adapter)
+{
+	return static_branch_unlikely(&igc_fpe_enabled) &&
+	       adapter->fpe.mmsv.pmac_enabled;
+}
+
+static inline bool igc_fpe_is_verify_or_response(union igc_adv_rx_desc *rx_desc,
+						 unsigned int size)
+{
+	u32 status_error = le32_to_cpu(rx_desc->wb.upper.status_error);
+	int smd;
+
+	smd = FIELD_GET(IGC_RXDADV_STAT_SMD_TYPE_MASK, status_error);
+
+	return ((smd == IGC_RXD_STAT_SMD_TYPE_V || smd == IGC_RXD_STAT_SMD_TYPE_R) &&
+		size == SMD_FRAME_SIZE);
+}
+
+static inline void igc_fpe_lp_event_status(union igc_adv_rx_desc *rx_desc,
+					   struct ethtool_mmsv *mmsv)
+{
+	u32 status_error = le32_to_cpu(rx_desc->wb.upper.status_error);
+	int smd;
+
+	smd = FIELD_GET(IGC_RXDADV_STAT_SMD_TYPE_MASK, status_error);
+
+	if (smd == IGC_RXD_STAT_SMD_TYPE_V)
+		ethtool_mmsv_event_handle(mmsv, ETHTOOL_MMSV_LP_SENT_VERIFY_MPACKET);
+	else if (smd == IGC_RXD_STAT_SMD_TYPE_R)
+		ethtool_mmsv_event_handle(mmsv, ETHTOOL_MMSV_LP_SENT_RESPONSE_MPACKET);
+}
+
+static inline bool igc_fpe_transmitted_smd_v(union igc_adv_tx_desc *tx_desc)
+{
+	u32 olinfo_status = le32_to_cpu(tx_desc->read.olinfo_status);
+	u8 smd = FIELD_GET(IGC_TXD_POPTS_SMD_MASK, olinfo_status);
+
+	return smd == SMD_V;
+}
+
 #endif /* _IGC_BASE_H */
-- 
2.34.1

Re: [PATCH iwl-next v5 5/9] igc: Add support for frame preemption verification

[Vladimir Oltean]

On Wed, Feb 19, 2025 at 09:53:45PM -0500, Faizal Rahim wrote:
> @@ -3956,6 +3970,30 @@ static int igc_uc_unsync(struct net_device *netdev, const unsigned char *addr)
>  	return 0;
>  }
>  
> +/**
> + * igc_enable_empty_addr_recv - Enable rx of packets with all-zeroes MAC address
> + * @adapter: Pointer to the igc_adapter structure.
> + *
> + * Frame preemption verification requires that packets with the all-zeroes
> + * MAC address are allowed to be received by IGC. This function adds the
> + * all-zeroes destination address to the list of acceptable addresses.
> + *
> + * Return: 0 on success, negative value otherwise.
> + */
> +int igc_enable_empty_addr_recv(struct igc_adapter *adapter)
> +{
> +	u8 empty[ETH_ALEN] = { };
> +
> +	return igc_add_mac_filter(adapter, IGC_MAC_FILTER_TYPE_DST, empty, -1);
> +}
> +
> +void igc_disable_empty_addr_recv(struct igc_adapter *adapter)
> +{
> +	u8 empty[ETH_ALEN] = { };
> +
> +	igc_del_mac_filter(adapter, IGC_MAC_FILTER_TYPE_DST, empty);
> +}
> +
>  /**
>   * igc_set_rx_mode - Secondary Unicast, Multicast and Promiscuous mode set
>   * @netdev: network interface device structure
> @@ -434,6 +569,11 @@ int igc_tsn_reset(struct igc_adapter *adapter)
>  	unsigned int new_flags;
>  	int err = 0;
>  
> +	if (adapter->fpe.mmsv.pmac_enabled)
> +		igc_enable_empty_addr_recv(adapter);
> +	else
> +		igc_disable_empty_addr_recv(adapter);
> +
>  	new_flags = igc_tsn_new_flags(adapter);
>  
>  	if (!(new_flags & IGC_FLAG_TSN_ANY_ENABLED))

Please monitor failures to add this MAC address filter somehow, don't
let errors be silent. If it returns -ENOSPC, you won't be able to
receive verification frames, but you'll never know it from the logs
(assuming the netdev_dbg() on the igc_add_mac_filter() success path
doesn't get printed anyway).

[PATCH iwl-next v5 6/9] igc: Add support to set tx-min-frag-size

[Faizal Rahim]

Add support to set tx-min-frag-size via set_mm callback in igc.
Increase the max limit of tx-ming-frag-size in ethtool from 252 to 256
since i225/6 value range is 64, 128, 192 and 256.

Co-developed-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Faizal Rahim <faizal.abdul.rahim@linux.intel.com>
---
 drivers/net/ethernet/intel/igc/igc.h         |  1 +
 drivers/net/ethernet/intel/igc/igc_defines.h |  1 +
 drivers/net/ethernet/intel/igc/igc_ethtool.c |  5 +++
 drivers/net/ethernet/intel/igc/igc_tsn.c     | 37 ++++++++++++++++++--
 drivers/net/ethernet/intel/igc/igc_tsn.h     |  2 +-
 net/ethtool/mm.c                             |  2 +-
 6 files changed, 43 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
index 705bd4739e3b..2f3662143589 100644
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -42,6 +42,7 @@ void igc_ethtool_set_ops(struct net_device *);
 
 struct fpe_t {
 	struct ethtool_mmsv mmsv;
+	u32 tx_min_frag_size;
 };
 
 enum igc_mac_filter_type {
diff --git a/drivers/net/ethernet/intel/igc/igc_defines.h b/drivers/net/ethernet/intel/igc/igc_defines.h
index 22db1de02964..038ee89f1e08 100644
--- a/drivers/net/ethernet/intel/igc/igc_defines.h
+++ b/drivers/net/ethernet/intel/igc/igc_defines.h
@@ -551,6 +551,7 @@
 #define IGC_TQAVCTRL_PREEMPT_ENA	0x00000002
 #define IGC_TQAVCTRL_ENHANCED_QAV	0x00000008
 #define IGC_TQAVCTRL_FUTSCDDIS		0x00000080
+#define IGC_TQAVCTRL_MIN_FRAG_MASK	0x0000C000
 
 #define IGC_TXQCTL_QUEUE_MODE_LAUNCHT	0x00000001
 #define IGC_TXQCTL_STRICT_CYCLE		0x00000002
diff --git a/drivers/net/ethernet/intel/igc/igc_ethtool.c b/drivers/net/ethernet/intel/igc/igc_ethtool.c
index e2a14edf7552..081e24f228b2 100644
--- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
+++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
@@ -1789,6 +1789,11 @@ static int igc_ethtool_set_mm(struct net_device *netdev,
 	struct igc_adapter *adapter = netdev_priv(netdev);
 	struct fpe_t *fpe = &adapter->fpe;
 
+	fpe->tx_min_frag_size = igc_fpe_get_supported_frag_size(cmd->tx_min_frag_size);
+	if (fpe->tx_min_frag_size != cmd->tx_min_frag_size)
+		NL_SET_ERR_MSG_MOD(extack,
+				   "tx-min-frag-size value set is unsupported. Rounded up to supported value (64, 128, 192, 256)");
+
 	if (fpe->mmsv.pmac_enabled != cmd->pmac_enabled) {
 		if (cmd->pmac_enabled)
 			static_branch_inc(&igc_fpe_enabled);
diff --git a/drivers/net/ethernet/intel/igc/igc_tsn.c b/drivers/net/ethernet/intel/igc/igc_tsn.c
index fbe3e70d8ea9..afb9aeec2885 100644
--- a/drivers/net/ethernet/intel/igc/igc_tsn.c
+++ b/drivers/net/ethernet/intel/igc/igc_tsn.c
@@ -7,6 +7,12 @@
 #include "igc_hw.h"
 #include "igc_tsn.h"
 
+#define MIN_MULTPLIER_TX_MIN_FRAG	0
+#define MAX_MULTPLIER_TX_MIN_FRAG	3
+/* Frag size is based on the Section 8.12.2 of the SW User Manual */
+#define TX_MIN_FRAG_SIZE		64
+#define TX_MAX_FRAG_SIZE	(TX_MIN_FRAG_SIZE * (MAX_MULTPLIER_TX_MIN_FRAG + 1))
+
 DEFINE_STATIC_KEY_FALSE(igc_fpe_enabled);
 
 static int igc_fpe_init_smd_frame(struct igc_ring *ring,
@@ -129,6 +135,7 @@ static const struct ethtool_mmsv_ops igc_mmsv_ops = {
 
 void igc_fpe_init(struct igc_adapter *adapter)
 {
+	adapter->fpe.tx_min_frag_size = TX_MIN_FRAG_SIZE;
 	ethtool_mmsv_init(&adapter->fpe.mmsv, adapter->netdev, &igc_mmsv_ops);
 }
 
@@ -279,7 +286,7 @@ static int igc_tsn_disable_offload(struct igc_adapter *adapter)
 	tqavctrl = rd32(IGC_TQAVCTRL);
 	tqavctrl &= ~(IGC_TQAVCTRL_TRANSMIT_MODE_TSN |
 		      IGC_TQAVCTRL_ENHANCED_QAV | IGC_TQAVCTRL_FUTSCDDIS |
-		      IGC_TQAVCTRL_PREEMPT_ENA);
+		      IGC_TQAVCTRL_PREEMPT_ENA | IGC_TQAVCTRL_MIN_FRAG_MASK);
 
 	wr32(IGC_TQAVCTRL, tqavctrl);
 
@@ -325,12 +332,34 @@ static void igc_tsn_set_retx_qbvfullthreshold(struct igc_adapter *adapter)
 	wr32(IGC_RETX_CTL, retxctl);
 }
 
+static u8 igc_fpe_get_frag_size_mult(const struct fpe_t *fpe)
+{
+	u8 mult = (fpe->tx_min_frag_size / TX_MIN_FRAG_SIZE) - 1;
+
+	return clamp_t(u8, mult, MIN_MULTPLIER_TX_MIN_FRAG,
+		       MAX_MULTPLIER_TX_MIN_FRAG);
+}
+
+u32 igc_fpe_get_supported_frag_size(u32 frag_size)
+{
+	const u32 supported_sizes[] = {64, 128, 192, 256};
+
+	/* Find the smallest supported size that is >= frag_size */
+	for (int i = 0; i < ARRAY_SIZE(supported_sizes); i++) {
+		if (frag_size <= supported_sizes[i])
+			return supported_sizes[i];
+	}
+
+	return TX_MAX_FRAG_SIZE; /* Should not happen, value > 256 is blocked by ethtool */
+}
+
 static int igc_tsn_enable_offload(struct igc_adapter *adapter)
 {
 	struct igc_hw *hw = &adapter->hw;
 	u32 tqavctrl, baset_l, baset_h;
 	u32 sec, nsec, cycle, rxpbs;
 	ktime_t base_time, systim;
+	u32 frag_size_mult;
 	int i;
 
 	wr32(IGC_TSAUXC, 0);
@@ -502,13 +531,15 @@ static int igc_tsn_enable_offload(struct igc_adapter *adapter)
 	}
 
 	tqavctrl = rd32(IGC_TQAVCTRL) & ~(IGC_TQAVCTRL_FUTSCDDIS |
-		   IGC_TQAVCTRL_PREEMPT_ENA);
-
+		   IGC_TQAVCTRL_PREEMPT_ENA | IGC_TQAVCTRL_MIN_FRAG_MASK);
 	tqavctrl |= IGC_TQAVCTRL_TRANSMIT_MODE_TSN | IGC_TQAVCTRL_ENHANCED_QAV;
 
 	if (adapter->fpe.mmsv.pmac_enabled)
 		tqavctrl |= IGC_TQAVCTRL_PREEMPT_ENA;
 
+	frag_size_mult = igc_fpe_get_frag_size_mult(&adapter->fpe);
+	tqavctrl |= FIELD_PREP(IGC_TQAVCTRL_MIN_FRAG_MASK, frag_size_mult);
+
 	adapter->qbv_count++;
 
 	cycle = adapter->cycle_time;
diff --git a/drivers/net/ethernet/intel/igc/igc_tsn.h b/drivers/net/ethernet/intel/igc/igc_tsn.h
index 7ba232ef37c9..7491fd65b846 100644
--- a/drivers/net/ethernet/intel/igc/igc_tsn.h
+++ b/drivers/net/ethernet/intel/igc/igc_tsn.h
@@ -14,7 +14,7 @@ enum igc_txd_popts_type {
 DECLARE_STATIC_KEY_FALSE(igc_fpe_enabled);
 
 void igc_fpe_init(struct igc_adapter *adapter);
-u32 igc_fpe_get_supported_frag_size(u32 user_frag_size);
+u32 igc_fpe_get_supported_frag_size(u32 frag_size);
 int igc_tsn_offload_apply(struct igc_adapter *adapter);
 int igc_tsn_reset(struct igc_adapter *adapter);
 void igc_tsn_adjust_txtime_offset(struct igc_adapter *adapter);
diff --git a/net/ethtool/mm.c b/net/ethtool/mm.c
index 7b2a75f94800..1e619894376f 100644
--- a/net/ethtool/mm.c
+++ b/net/ethtool/mm.c
@@ -153,7 +153,7 @@ const struct nla_policy ethnl_mm_set_policy[ETHTOOL_A_MM_MAX + 1] = {
 	[ETHTOOL_A_MM_VERIFY_TIME]	= NLA_POLICY_RANGE(NLA_U32, 1, 128),
 	[ETHTOOL_A_MM_TX_ENABLED]	= NLA_POLICY_MAX(NLA_U8, 1),
 	[ETHTOOL_A_MM_PMAC_ENABLED]	= NLA_POLICY_MAX(NLA_U8, 1),
-	[ETHTOOL_A_MM_TX_MIN_FRAG_SIZE]	= NLA_POLICY_RANGE(NLA_U32, 60, 252),
+	[ETHTOOL_A_MM_TX_MIN_FRAG_SIZE]	= NLA_POLICY_RANGE(NLA_U32, 60, 256),
 };
 
 static void mm_state_to_cfg(const struct ethtool_mm_state *state,
-- 
2.34.1

[PATCH iwl-next v5 7/9] igc: Add support to get MAC Merge data via ethtool

[Faizal Rahim]

Implement "ethtool --show-mm" callback for IGC.

Tested with command:
$ ethtool --show-mm enp1s0.
  MAC Merge layer state for enp1s0:
  pMAC enabled: on
  TX enabled: on
  TX active: on
  TX minimum fragment size: 64
  RX minimum fragment size: 60
  Verify enabled: on
  Verify time: 128
  Max verify time: 128
  Verification status: SUCCEEDED

Verified that the fields value are retrieved correctly.

Signed-off-by: Faizal Rahim <faizal.abdul.rahim@linux.intel.com>
---
 drivers/net/ethernet/intel/igc/igc_ethtool.c | 14 ++++++++++++++
 drivers/net/ethernet/intel/igc/igc_tsn.h     |  1 +
 2 files changed, 15 insertions(+)

diff --git a/drivers/net/ethernet/intel/igc/igc_ethtool.c b/drivers/net/ethernet/intel/igc/igc_ethtool.c
index 081e24f228b2..7f0052e0d50c 100644
--- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
+++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
@@ -1782,6 +1782,19 @@ static int igc_ethtool_set_eee(struct net_device *netdev,
 	return 0;
 }
 
+static int igc_ethtool_get_mm(struct net_device *netdev,
+			      struct ethtool_mm_state *cmd)
+{
+	struct igc_adapter *adapter = netdev_priv(netdev);
+	struct fpe_t *fpe = &adapter->fpe;
+
+	ethtool_mmsv_get_mm(&fpe->mmsv, cmd);
+	cmd->tx_min_frag_size = fpe->tx_min_frag_size;
+	cmd->rx_min_frag_size = IGC_RX_MIN_FRAG_SIZE;
+
+	return 0;
+}
+
 static int igc_ethtool_set_mm(struct net_device *netdev,
 			      struct ethtool_mm_cfg *cmd,
 			      struct netlink_ext_ack *extack)
@@ -2093,6 +2106,7 @@ static const struct ethtool_ops igc_ethtool_ops = {
 	.set_rxfh		= igc_ethtool_set_rxfh,
 	.get_ts_info		= igc_ethtool_get_ts_info,
 	.get_channels		= igc_ethtool_get_channels,
+	.get_mm			= igc_ethtool_get_mm,
 	.set_mm			= igc_ethtool_set_mm,
 	.set_channels		= igc_ethtool_set_channels,
 	.get_priv_flags		= igc_ethtool_get_priv_flags,
diff --git a/drivers/net/ethernet/intel/igc/igc_tsn.h b/drivers/net/ethernet/intel/igc/igc_tsn.h
index 7491fd65b846..14495a22f77d 100644
--- a/drivers/net/ethernet/intel/igc/igc_tsn.h
+++ b/drivers/net/ethernet/intel/igc/igc_tsn.h
@@ -4,6 +4,7 @@
 #ifndef _IGC_TSN_H_
 #define _IGC_TSN_H_
 
+#define IGC_RX_MIN_FRAG_SIZE		60
 #define SMD_FRAME_SIZE			60
 
 enum igc_txd_popts_type {
-- 
2.34.1

[PATCH iwl-next v5 8/9] igc: Add support to get frame preemption statistics via ethtool

[Faizal Rahim]

Implemented "ethtool --include-statistics --show-mm" callback for IGC.

Tested preemption scenario to check preemption statistics:
1) Trigger verification handshake on both boards:
    $ sudo ethtool --set-mm enp1s0 pmac-enabled on
    $ sudo ethtool --set-mm enp1s0 tx-enabled on
    $ sudo ethtool --set-mm enp1s0 verify-enabled on
2) Set preemptible or express queue in taprio for tx board:
    $ sudo tc qdisc replace dev enp1s0 parent root handle 100 taprio \
      num_tc 4 map 3 2 1 0 3 3 3 3 3 3 3 3 3 3 3 3 \
      queues 1@0 1@1 1@2 1@3 base-time 0 sched-entry S F 100000 \
      fp E E P P
3) Send large size packets on preemptible queue
4) Send small size packets on express queue to preempt packets in
   preemptible queue
5) Show preemption statistics on the receiving board:
   $ ethtool --include-statistics --show-mm enp1s0
     MAC Merge layer state for enp1s0:
     pMAC enabled: on
     TX enabled: on
     TX active: on
     TX minimum fragment size: 64
     RX minimum fragment size: 60
     Verify enabled: on
     Verify time: 128
     Max verify time: 128
     Verification status: SUCCEEDED
     Statistics:
      MACMergeFrameAssErrorCount: 0
      MACMergeFrameSmdErrorCount: 0
      MACMergeFrameAssOkCount: 511
      MACMergeFragCountRx: 764
      MACMergeFragCountTx: 0
      MACMergeHoldCount: 0

Co-developed-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Faizal Rahim <faizal.abdul.rahim@linux.intel.com>
---
 drivers/net/ethernet/intel/igc/igc_ethtool.c | 36 ++++++++++++++++++++
 drivers/net/ethernet/intel/igc/igc_regs.h    | 16 +++++++++
 2 files changed, 52 insertions(+)

diff --git a/drivers/net/ethernet/intel/igc/igc_ethtool.c b/drivers/net/ethernet/intel/igc/igc_ethtool.c
index 7f0052e0d50c..97a1194399b1 100644
--- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
+++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
@@ -1819,6 +1819,41 @@ static int igc_ethtool_set_mm(struct net_device *netdev,
 	return igc_tsn_offload_apply(adapter);
 }
 
+/**
+ * igc_ethtool_get_frame_ass_error - Get the frame assembly error count.
+ * @dev: Pointer to the net_device structure.
+ * Return: The count of frame assembly errors.
+ */
+static u64 igc_ethtool_get_frame_ass_error(struct net_device *dev)
+{
+	struct igc_adapter *adapter = netdev_priv(dev);
+	u32 ooo_smdc, ooo_frame_cnt, ooo_frag_cnt; /* Out of order statistics */
+	struct igc_hw *hw = &adapter->hw;
+	u32 miss_frame_frag_cnt;
+	u32 reg_value;
+
+	reg_value = rd32(IGC_PRMEXPRCNT);
+	ooo_smdc = FIELD_GET(IGC_PRMEXPRCNT_OOO_SMDC, reg_value);
+	ooo_frame_cnt = FIELD_GET(IGC_PRMEXPRCNT_OOO_FRAME_CNT, reg_value);
+	ooo_frag_cnt = FIELD_GET(IGC_PRMEXPRCNT_OOO_FRAG_CNT, reg_value);
+	miss_frame_frag_cnt = FIELD_GET(IGC_PRMEXPRCNT_MISS_FRAME_FRAG_CNT,
+					reg_value);
+
+	return ooo_smdc + ooo_frame_cnt + ooo_frag_cnt + miss_frame_frag_cnt;
+}
+
+static void igc_ethtool_get_mm_stats(struct net_device *dev,
+				     struct ethtool_mm_stats *stats)
+{
+	struct igc_adapter *adapter = netdev_priv(dev);
+	struct igc_hw *hw = &adapter->hw;
+
+	stats->MACMergeFrameAssErrorCount = igc_ethtool_get_frame_ass_error(dev);
+	stats->MACMergeFrameAssOkCount = rd32(IGC_PRMPTDRCNT);
+	stats->MACMergeFragCountRx =  rd32(IGC_PRMEVNTRCNT);
+	stats->MACMergeFragCountTx = rd32(IGC_PRMEVNTTCNT);
+}
+
 static int igc_ethtool_get_link_ksettings(struct net_device *netdev,
 					  struct ethtool_link_ksettings *cmd)
 {
@@ -2108,6 +2143,7 @@ static const struct ethtool_ops igc_ethtool_ops = {
 	.get_channels		= igc_ethtool_get_channels,
 	.get_mm			= igc_ethtool_get_mm,
 	.set_mm			= igc_ethtool_set_mm,
+	.get_mm_stats		= igc_ethtool_get_mm_stats,
 	.set_channels		= igc_ethtool_set_channels,
 	.get_priv_flags		= igc_ethtool_get_priv_flags,
 	.set_priv_flags		= igc_ethtool_set_priv_flags,
diff --git a/drivers/net/ethernet/intel/igc/igc_regs.h b/drivers/net/ethernet/intel/igc/igc_regs.h
index 12ddc5793651..41dbfb07eb2f 100644
--- a/drivers/net/ethernet/intel/igc/igc_regs.h
+++ b/drivers/net/ethernet/intel/igc/igc_regs.h
@@ -222,6 +222,22 @@
 
 #define IGC_FTQF(_n)	(0x059E0 + (4 * (_n)))  /* 5-tuple Queue Fltr */
 
+/* Time sync registers - preemption statistics */
+#define IGC_PRMPTDRCNT		0x04284	/* Good RX Preempted Packets */
+#define IGC_PRMEVNTTCNT		0x04298	/* TX Preemption event counter */
+#define IGC_PRMEVNTRCNT		0x0429C	/* RX Preemption event counter */
+
+ /* Preemption Exception Counter */
+#define IGC_PRMEXPRCNT					0x42A0
+/* Received out of order packets with SMD-C */
+#define IGC_PRMEXPRCNT_OOO_SMDC				0x000000FF
+/* Received out of order packets with SMD-C and wrong Frame CNT */
+#define IGC_PRMEXPRCNT_OOO_FRAME_CNT			0x0000FF00
+/* Received out of order packets with SMD-C and wrong Frag CNT */
+#define IGC_PRMEXPRCNT_OOO_FRAG_CNT			0x00FF0000
+/* Received packets with SMD-S and wrong Frag CNT and Frame CNT */
+#define IGC_PRMEXPRCNT_MISS_FRAME_FRAG_CNT		0xFF000000
+
 /* Transmit Scheduling Registers */
 #define IGC_TQAVCTRL		0x3570
 #define IGC_TXQCTL(_n)		(0x3344 + 0x4 * (_n))
-- 
2.34.1

[PATCH iwl-next v5 9/9] igc: Block setting preemptible traffic class in taprio

[Faizal Rahim]

Since preemptible tc implementation is not ready yet, block it from being
set in taprio. The existing code already blocks it in mqprio.

Signed-off-by: Faizal Rahim <faizal.abdul.rahim@linux.intel.com>
---
 drivers/net/ethernet/intel/igc/igc_main.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 5a6648a12a53..e6a398dbf09b 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -6408,6 +6408,10 @@ static int igc_save_qbv_schedule(struct igc_adapter *adapter,
 	if (!validate_schedule(adapter, qopt))
 		return -EINVAL;
 
+	/* preemptible isn't supported yet */
+	if (qopt->mqprio.preemptible_tcs)
+		return -EOPNOTSUPP;
+
 	igc_ptp_read(adapter, &now);
 
 	if (igc_tsn_is_taprio_activated_by_user(adapter) &&
-- 
2.34.1

Re: [PATCH iwl-next v5 9/9] igc: Block setting preemptible traffic class in taprio

[Vladimir Oltean]

On Wed, Feb 19, 2025 at 09:53:49PM -0500, Faizal Rahim wrote:
> Since preemptible tc implementation is not ready yet, block it from being
> set in taprio. The existing code already blocks it in mqprio.
> 
> Signed-off-by: Faizal Rahim <faizal.abdul.rahim@linux.intel.com>
> ---
>  drivers/net/ethernet/intel/igc/igc_main.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
> index 5a6648a12a53..e6a398dbf09b 100644
> --- a/drivers/net/ethernet/intel/igc/igc_main.c
> +++ b/drivers/net/ethernet/intel/igc/igc_main.c
> @@ -6408,6 +6408,10 @@ static int igc_save_qbv_schedule(struct igc_adapter *adapter,
>  	if (!validate_schedule(adapter, qopt))
>  		return -EINVAL;
>  
> +	/* preemptible isn't supported yet */
> +	if (qopt->mqprio.preemptible_tcs)
> +		return -EOPNOTSUPP;
> +
>  	igc_ptp_read(adapter, &now);
>  
>  	if (igc_tsn_is_taprio_activated_by_user(adapter) &&
> -- 
> 2.34.1
>

This patch should be before the patch that makes ethtool_dev_mm_supported()
return true for igc, i.e. 7/9 "igc: Add support to get MAC Merge data via ethtool".
You don't want the kernel to be in a state at all where it accepts a
configuration it doesn't support, even if it's temporary and you're
fixing it up within the same patch set, because it may be visible during
e.g. a git bisect.

Re: [PATCH iwl-next v5 0/9] igc: Add support for Frame Preemption feature in IGC

[Vladimir Oltean]

On Wed, Feb 19, 2025 at 09:53:40PM -0500, Faizal Rahim wrote:
> Introduces support for the FPE feature in the IGC driver.
> 
> The patches aligns with the upstream FPE API:
> https://patchwork.kernel.org/project/netdevbpf/cover/20230220122343.1156614-1-vladimir.oltean@nxp.com/
> https://patchwork.kernel.org/project/netdevbpf/cover/20230119122705.73054-1-vladimir.oltean@nxp.com/
> 
> It builds upon earlier work:
> https://patchwork.kernel.org/project/netdevbpf/cover/20220520011538.1098888-1-vinicius.gomes@intel.com/
> 
> The patch series adds the following functionalities to the IGC driver:
> a) Configure FPE using `ethtool --set-mm`.
> b) Display FPE settings via `ethtool --show-mm`.
> c) View FPE statistics using `ethtool --include-statistics --show-mm'.
> e) Block setting preemptible tc in taprio since it is not supported yet.
>    Existing code already blocks it in mqprio.

Thanks for the work, the patch set looks ok to me apart from the minor things I highlighted.
It would be good to know that you've tested:
- a netdev down/up cycle
- a suspend/resume cycle
- with CONFIG_PROVE_LOCKING, CONFIG_DEBUG_ATOMIC_SLEEP, CONFIG_DMA_API_DEBUG,
  CONFIG_KASAN all enabled
- the kselftest again
just so we have more confidence we are not missing some non-obvious issues.

@Furong, the set looks close to final state to me, would you mind
leaving a Tested-by: tag on patch 1/9?