[patch 3/4] Configure out ethtool support

From: Thomas Petazzoni
Date: Thu Jul 31 2008 - 05:34:12 EST

This patchs add the CONFIG_ETHTOOL option which allows to remove
support for ethtool, not necessarly used on embedded systems. As this
is a size-reduction option, it depends on CONFIG_EMBEDDED. It allows
to save ~6 kilobytes of kernel code:

text data bss dec hex filename
1258447 123592 212992 1595031 185697 vmlinux
1252147 123592 212992 1588731 183dfb vmlinux.new
-6300 0 0 -6300 -189C +/-

Bonding and bridging both depends on Ethtool functionnality, so
ETHTOOL is selected automatically when either bonding and bridging are
selected.

Question: should we also remove ethtool-related functions from all
network drivers ?

This patch has been originally written by Matt Mackall
<mpm@xxxxxxxxxxx>, and is part of the Linux Tiny project.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Matt Mackall <mpm@xxxxxxxxxxx>
Cc: jgarzik@xxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
Cc: davem@xxxxxxxxxxxxx
Cc: mpm@xxxxxxxxxxx
Cc: akpm@xxxxxxxxxxxxxxxxxxxx

---
drivers/net/Kconfig | 1 +
include/linux/ethtool.h | 16 ++++++++++++++++
init/Kconfig | 8 ++++++++
net/bridge/Kconfig | 1 +
net/core/Makefile | 3 ++-
net/core/dev.c | 4 ++++
6 files changed, 32 insertions(+), 1 deletion(-)

Index: linuxdev/drivers/net/Kconfig
===================================================================
--- linuxdev.orig/drivers/net/Kconfig
+++ linuxdev/drivers/net/Kconfig
@@ -61,6 +61,7 @@
config BONDING
tristate "Bonding driver support"
depends on INET
+ select ETHTOOL
---help---
Say 'Y' or 'M' if you wish to be able to 'bond' multiple Ethernet
Channels together. This is called 'Etherchannel' by Cisco,
Index: linuxdev/include/linux/ethtool.h
===================================================================
--- linuxdev.orig/include/linux/ethtool.h
+++ linuxdev/include/linux/ethtool.h
@@ -283,6 +283,7 @@
struct net_device;

/* Some generic methods drivers may use in their ethtool_ops */
+#ifdef CONFIG_ETHTOOL
u32 ethtool_op_get_link(struct net_device *dev);
u32 ethtool_op_get_tx_csum(struct net_device *dev);
int ethtool_op_set_tx_csum(struct net_device *dev, u32 data);
@@ -296,6 +297,21 @@
int ethtool_op_set_ufo(struct net_device *dev, u32 data);
u32 ethtool_op_get_flags(struct net_device *dev);
int ethtool_op_set_flags(struct net_device *dev, u32 data);
+#else
+static inline u32 ethtool_op_get_link(struct net_device *dev) { return 0; }
+static inline u32 ethtool_op_get_tx_csum(struct net_device *dev) { return 0; }
+static inline int ethtool_op_set_tx_csum(struct net_device *dev, u32 data) { return 0; }
+static inline int ethtool_op_set_tx_hw_csum(struct net_device *dev, u32 data) { return 0; }
+static inline int ethtool_op_set_tx_ipv6_csum(struct net_device *dev, u32 data) { return 0; }
+static inline u32 ethtool_op_get_sg(struct net_device *dev) { return 0; }
+static inline int ethtool_op_set_sg(struct net_device *dev, u32 data) { return 0; }
+static inline u32 ethtool_op_get_tso(struct net_device *dev) { return 0; }
+static inline int ethtool_op_set_tso(struct net_device *dev, u32 data) { return 0; }
+static inline u32 ethtool_op_get_ufo(struct net_device *dev) { return 0; }
+static inline int ethtool_op_set_ufo(struct net_device *dev, u32 data) { return 0; }
+static inline u32 ethtool_op_get_flags(struct net_device *dev) { return 0; }
+static inline int ethtool_op_set_flags(struct net_device *dev, u32 data) { return 0; }
+#endif

/**
* &ethtool_ops - Alter and report network device settings
Index: linuxdev/init/Kconfig
===================================================================
--- linuxdev.orig/init/Kconfig
+++ linuxdev/init/Kconfig
@@ -740,6 +740,14 @@
for filesystems like NFS and for the flock() system
call. Disabling this option saves about 11k.

+config ETHTOOL
+ bool "Enable ethtool support" if EMBEDDED
+ depends on NET
+ default y
+ help
+ Disabling this option removes support for configuring
+ ethernet device features via ethtool. Saves about 6k.
+
config VM_EVENT_COUNTERS
default y
bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
Index: linuxdev/net/bridge/Kconfig
===================================================================
--- linuxdev.orig/net/bridge/Kconfig
+++ linuxdev/net/bridge/Kconfig
@@ -6,6 +6,7 @@
tristate "802.1d Ethernet Bridging"
select LLC
select STP
+ select ETHTOOL
---help---
If you say Y here, then your Linux box will be able to act as an
Ethernet bridge, which means that the different Ethernet segments it
Index: linuxdev/net/core/Makefile
===================================================================
--- linuxdev.orig/net/core/Makefile
+++ linuxdev/net/core/Makefile
@@ -7,10 +7,11 @@

obj-$(CONFIG_SYSCTL) += sysctl_net_core.o

-obj-y += dev.o ethtool.o dev_mcast.o dst.o netevent.o \
+obj-y += dev.o dev_mcast.o dst.o netevent.o \
neighbour.o rtnetlink.o utils.o link_watch.o filter.o

obj-$(CONFIG_XFRM) += flow.o
+obj-$(CONFIG_ETHTOOL) += ethtool.o
obj-y += net-sysfs.o
obj-$(CONFIG_NET_PKTGEN) += pktgen.o
obj-$(CONFIG_NETPOLL) += netpoll.o
Index: linuxdev/net/core/dev.c
===================================================================
--- linuxdev.orig/net/core/dev.c
+++ linuxdev/net/core/dev.c
@@ -3669,6 +3669,7 @@
return ret;

case SIOCETHTOOL:
+#ifdef CONFIG_ETHTOOL
dev_load(net, ifr.ifr_name);
rtnl_lock();
ret = dev_ethtool(net, &ifr);
@@ -3681,6 +3682,9 @@
ret = -EFAULT;
}
return ret;
+#else
+ return -EINVAL;
+#endif

/*
* These ioctl calls:

--
Thomas Petazzoni, Free Electrons
Kernel, drivers and embedded Linux development,
consulting, training and support.
http://free-electrons.com
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