Commit 14870b75 authored by Esben Haabendal's avatar Esben Haabendal Committed by David S. Miller
Browse files

net: gianfar: Implement rx_missed_errors counter 



Devices with RMON support has a 16-bit RDRP counter.  It provides: "Receive
dropped packets counter. Increments for frames received which are streamed
to system but are later dropped due to lack of system resources."

To handle more than 2^16 dropped packets, a carry bit in CAR1 register is
set on overflow, so we enable irq when this is set, extending the counter
to 2^64 for handling situations where lots of packets are missed (e.g.
during heavy network storms).

Signed-off-by: default avatarEsben Haabendal <esben@geanix.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8da32a10

drivers/net/ethernet/freescale/gianfar.c

+47 −3
Original line number Diff line number Diff line
@@ -289,6 +289,29 @@ static void gfar_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *s 
		stats->tx_bytes += priv->tx_queue[i]->stats.tx_bytes;

		stats->tx_packets += priv->tx_queue[i]->stats.tx_packets;

	}



	if (priv->device_flags & FSL_GIANFAR_DEV_HAS_RMON) {

		struct rmon_mib __iomem *rmon = &priv->gfargrp[0].regs->rmon;

		unsigned long flags;

		u32 rdrp, car, car_before;

		u64 rdrp_offset;



		spin_lock_irqsave(&priv->rmon_overflow.lock, flags);

		car = gfar_read(&rmon->car1) & CAR1_C1RDR;

		do {

			car_before = car;

			rdrp = gfar_read(&rmon->rdrp);

			car = gfar_read(&rmon->car1) & CAR1_C1RDR;

		} while (car != car_before);

		if (car) {

			priv->rmon_overflow.rdrp++;

			gfar_write(&rmon->car1, car);

		}

		rdrp_offset = priv->rmon_overflow.rdrp;

		spin_unlock_irqrestore(&priv->rmon_overflow.lock, flags);



		stats->rx_missed_errors = rdrp + (rdrp_offset << 16);

	}

}



/* Set the appropriate hash bit for the given addr */
@@ -379,7 +402,8 @@ static void gfar_ints_enable(struct gfar_private *priv) 
	for (i = 0; i < priv->num_grps; i++) {

		struct gfar __iomem *regs = priv->gfargrp[i].regs;

		/* Unmask the interrupts we look for */

		gfar_write(&regs->imask, IMASK_DEFAULT);

		gfar_write(&regs->imask,

			   IMASK_DEFAULT | priv->rmon_overflow.imask);

	}

}
@@ -2287,7 +2311,7 @@ static irqreturn_t gfar_receive(int irq, void *grp_id) 
	if (likely(napi_schedule_prep(&grp->napi_rx))) {

		spin_lock_irqsave(&grp->grplock, flags);

		imask = gfar_read(&grp->regs->imask);

		imask &= IMASK_RX_DISABLED;

		imask &= IMASK_RX_DISABLED | grp->priv->rmon_overflow.imask;

		gfar_write(&grp->regs->imask, imask);

		spin_unlock_irqrestore(&grp->grplock, flags);

		__napi_schedule(&grp->napi_rx);
@@ -2311,7 +2335,7 @@ static irqreturn_t gfar_transmit(int irq, void *grp_id) 
	if (likely(napi_schedule_prep(&grp->napi_tx))) {

		spin_lock_irqsave(&grp->grplock, flags);

		imask = gfar_read(&grp->regs->imask);

		imask &= IMASK_TX_DISABLED;

		imask &= IMASK_TX_DISABLED | grp->priv->rmon_overflow.imask;

		gfar_write(&grp->regs->imask, imask);

		spin_unlock_irqrestore(&grp->grplock, flags);

		__napi_schedule(&grp->napi_tx);
@@ -2682,6 +2706,18 @@ static irqreturn_t gfar_error(int irq, void *grp_id) 
		}

		netif_dbg(priv, tx_err, dev, "Transmit Error\n");

	}

	if (events & IEVENT_MSRO) {

		struct rmon_mib __iomem *rmon = &regs->rmon;

		u32 car;



		spin_lock(&priv->rmon_overflow.lock);

		car = gfar_read(&rmon->car1) & CAR1_C1RDR;

		if (car) {

			priv->rmon_overflow.rdrp++;

			gfar_write(&rmon->car1, car);

		}

		spin_unlock(&priv->rmon_overflow.lock);

	}

	if (events & IEVENT_BSY) {

		dev->stats.rx_over_errors++;

		atomic64_inc(&priv->extra_stats.rx_bsy);
@@ -3259,6 +3295,14 @@ static int gfar_probe(struct platform_device *ofdev) 


	gfar_hw_init(priv);



	if (priv->device_flags & FSL_GIANFAR_DEV_HAS_RMON) {

		struct rmon_mib __iomem *rmon = &priv->gfargrp[0].regs->rmon;



		spin_lock_init(&priv->rmon_overflow.lock);

		priv->rmon_overflow.imask = IMASK_MSRO;

		gfar_write(&rmon->cam1, gfar_read(&rmon->cam1) & ~CAM1_M1RDR);

	}



	/* Carrier starts down, phylib will bring it up */

	netif_carrier_off(dev);

drivers/net/ethernet/freescale/gianfar.h

+10 −0
Original line number Diff line number Diff line
@@ -663,6 +663,15 @@ struct rmon_mib 
	u32	cam2;	/* 0x.73c - Carry Mask Register Two */

};



struct rmon_overflow {

	/* lock for synchronization of the rdrp field of this struct, and

	 * CAR1/CAR2 registers

	 */

	spinlock_t lock;

	u32	imask;

	u64	rdrp;

};



struct gfar_extra_stats {

	atomic64_t rx_alloc_err;

	atomic64_t rx_large;
@@ -1150,6 +1159,7 @@ struct gfar_private { 


	/* Network Statistics */

	struct gfar_extra_stats extra_stats;

	struct rmon_overflow rmon_overflow;



	/* PHY stuff */

	phy_interface_t interface;