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Commit f0cdf76c authored by Florian Westphal's avatar Florian Westphal Committed by David S. Miller
Browse files

net: remove NETDEV_TX_LOCKED support 



No more users in the tree, remove NETDEV_TX_LOCKED support.
Adds another hole in softnet_stats struct, but better than keeping
the unused collision counter around.

Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a6086a89

Documentation/networking/netdev-features.txt

+4 −6
Original line number Diff line number Diff line
@@ -131,13 +131,11 @@ stack. Driver should not change behaviour based on them. 


 * LLTX driver (deprecated for hardware drivers)



NETIF_F_LLTX should be set in drivers that implement their own locking in

transmit path or don't need locking at all (e.g. software tunnels).

In ndo_start_xmit, it is recommended to use a try_lock and return

NETDEV_TX_LOCKED when the spin lock fails.  The locking should also properly

protect against other callbacks (the rules you need to find out).

NETIF_F_LLTX is meant to be used by drivers that don't need locking at all,

e.g. software tunnels.



Don't use it for new drivers.

This is also used in a few legacy drivers that implement their

own locking, don't use it for new (hardware) drivers.



 * netns-local device

Documentation/networking/netdevices.txt

+3 −6
Original line number Diff line number Diff line
@@ -69,10 +69,9 @@ ndo_start_xmit: 


	When the driver sets NETIF_F_LLTX in dev->features this will be

	called without holding netif_tx_lock. In this case the driver

	has to lock by itself when needed. It is recommended to use a try lock

	for this and return NETDEV_TX_LOCKED when the spin lock fails.

	has to lock by itself when needed.

	The locking there should also properly protect against

	set_rx_mode. Note that the use of NETIF_F_LLTX is deprecated.

	set_rx_mode. WARNING: use of NETIF_F_LLTX is deprecated.

	Don't use it for new drivers.



	Context: Process with BHs disabled or BH (timer),
@@ -83,8 +82,6 @@ ndo_start_xmit: 
	o NETDEV_TX_BUSY Cannot transmit packet, try later 

	  Usually a bug, means queue start/stop flow control is broken in

	  the driver. Note: the driver must NOT put the skb in its DMA ring.

	o NETDEV_TX_LOCKED Locking failed, please retry quickly.

	  Only valid when NETIF_F_LLTX is set.



ndo_tx_timeout:

	Synchronization: netif_tx_lock spinlock; all TX queues frozen.

include/linux/netdevice.h

+0 −3
Original line number Diff line number Diff line
@@ -106,7 +106,6 @@ enum netdev_tx { 
	__NETDEV_TX_MIN	 = INT_MIN,	/* make sure enum is signed */

	NETDEV_TX_OK	 = 0x00,	/* driver took care of packet */

	NETDEV_TX_BUSY	 = 0x10,	/* driver tx path was busy*/

	NETDEV_TX_LOCKED = 0x20,	/* driver tx lock was already taken */

};

typedef enum netdev_tx netdev_tx_t;
@@ -831,7 +830,6 @@ struct tc_to_netdev { 
 *	the queue before that can happen; it's for obsolete devices and weird

 *	corner cases, but the stack really does a non-trivial amount

 *	of useless work if you return NETDEV_TX_BUSY.

 *        (can also return NETDEV_TX_LOCKED iff NETIF_F_LLTX)

 *	Required; cannot be NULL.

 *

 * netdev_features_t (*ndo_fix_features)(struct net_device *dev,
@@ -2737,7 +2735,6 @@ struct softnet_data { 
	/* stats */

	unsigned int		processed;

	unsigned int		time_squeeze;

	unsigned int		cpu_collision;

	unsigned int		received_rps;

#ifdef CONFIG_RPS

	struct softnet_data	*rps_ipi_list;

net/core/net-procfs.c

+2 −1
Original line number Diff line number Diff line
@@ -162,7 +162,8 @@ static int softnet_seq_show(struct seq_file *seq, void *v) 
		   "%08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x\n",

		   sd->processed, sd->dropped, sd->time_squeeze, 0,

		   0, 0, 0, 0, /* was fastroute */

		   sd->cpu_collision, sd->received_rps, flow_limit_count);

		   0,	/* was cpu_collision */

		   sd->received_rps, flow_limit_count);

	return 0;

}

net/core/pktgen.c

+0 −1
Original line number Diff line number Diff line
@@ -3472,7 +3472,6 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev) 
				     pkt_dev->odevname, ret);

		pkt_dev->errors++;

		/* fallthru */

	case NETDEV_TX_LOCKED:

	case NETDEV_TX_BUSY:

		/* Retry it next time */

		atomic_dec(&(pkt_dev->skb->users));