Message ID | 1456911665-1424389-1-git-send-email-arnd@arndb.de |
---|---|
State | Accepted, archived |
Delegated to: | David Miller |
Headers | show |
Wed, Mar 02, 2016 at 10:40:54AM CET, arnd@arndb.de wrote: >The new NET_DEVLINK infrastructure can be a loadable module, but the drivers >using it might be built-in, which causes link errors like: > >drivers/net/built-in.o: In function `mlx4_load_one': >:(.text+0x2fbfda): undefined reference to `devlink_port_register' >:(.text+0x2fc084): undefined reference to `devlink_port_unregister' >drivers/net/built-in.o: In function `mlxsw_sx_port_remove': >:(.text+0x33a03a): undefined reference to `devlink_port_type_clear' >:(.text+0x33a04e): undefined reference to `devlink_port_unregister' > >There are multiple ways to avoid this: > >a) add 'depends on NET_DEVLINK || !NET_DEVLINK' dependencies > for each user >b) use 'select NET_DEVLINK' from each driver that uses it > and hide the symbol in Kconfig. >c) make NET_DEVLINK a 'bool' option so we don't have to > list it as a dependency, and rely on the APIs to be > stubbed out when it is disabled >d) use IS_REACHABLE() rather than IS_ENABLED() to check for > NET_DEVLINK in include/net/devlink.h > >This implements a variation of approach a) by adding an >intermediate symbol that drivers can depend on, and changes >the three drivers using it. Approach a) looks like the best. Thanks for taking care of this. > >Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Jiri Pirko <jiri@mellanox.com>
From: Arnd Bergmann <arnd@arndb.de> Date: Wed, 2 Mar 2016 10:40:54 +0100 > The new NET_DEVLINK infrastructure can be a loadable module, but the drivers > using it might be built-in, which causes link errors like: > > drivers/net/built-in.o: In function `mlx4_load_one': > :(.text+0x2fbfda): undefined reference to `devlink_port_register' > :(.text+0x2fc084): undefined reference to `devlink_port_unregister' > drivers/net/built-in.o: In function `mlxsw_sx_port_remove': > :(.text+0x33a03a): undefined reference to `devlink_port_type_clear' > :(.text+0x33a04e): undefined reference to `devlink_port_unregister' > > There are multiple ways to avoid this: > > a) add 'depends on NET_DEVLINK || !NET_DEVLINK' dependencies > for each user > b) use 'select NET_DEVLINK' from each driver that uses it > and hide the symbol in Kconfig. > c) make NET_DEVLINK a 'bool' option so we don't have to > list it as a dependency, and rely on the APIs to be > stubbed out when it is disabled > d) use IS_REACHABLE() rather than IS_ENABLED() to check for > NET_DEVLINK in include/net/devlink.h > > This implements a variation of approach a) by adding an > intermediate symbol that drivers can depend on, and changes > the three drivers using it. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > Fixes: 09d4d087cd48 ("mlx4: Implement devlink interface") > Fixes: c4745500e988 ("mlxsw: Implement devlink interface") Applied, thanks Arnd.
diff --git a/drivers/infiniband/hw/mlx4/Kconfig b/drivers/infiniband/hw/mlx4/Kconfig index fc01deac1d3c..db4aa13ebae0 100644 --- a/drivers/infiniband/hw/mlx4/Kconfig +++ b/drivers/infiniband/hw/mlx4/Kconfig @@ -1,6 +1,7 @@ config MLX4_INFINIBAND tristate "Mellanox ConnectX HCA support" depends on NETDEVICES && ETHERNET && PCI && INET + depends on MAY_USE_DEVLINK select NET_VENDOR_MELLANOX select MLX4_CORE ---help--- diff --git a/drivers/net/ethernet/mellanox/mlx4/Kconfig b/drivers/net/ethernet/mellanox/mlx4/Kconfig index 1486ce902a56..9ca3734ebb6b 100644 --- a/drivers/net/ethernet/mellanox/mlx4/Kconfig +++ b/drivers/net/ethernet/mellanox/mlx4/Kconfig @@ -4,6 +4,7 @@ config MLX4_EN tristate "Mellanox Technologies 1/10/40Gbit Ethernet support" + depends on MAY_USE_DEVLINK depends on PCI select MLX4_CORE select PTP_1588_CLOCK diff --git a/drivers/net/ethernet/mellanox/mlxsw/Kconfig b/drivers/net/ethernet/mellanox/mlxsw/Kconfig index ce26adcb4988..2ad7f67854d5 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/Kconfig +++ b/drivers/net/ethernet/mellanox/mlxsw/Kconfig @@ -4,6 +4,7 @@ config MLXSW_CORE tristate "Mellanox Technologies Switch ASICs support" + depends on MAY_USE_DEVLINK ---help--- This driver supports Mellanox Technologies Switch ASICs family. diff --git a/net/Kconfig b/net/Kconfig index 6c9cfb0d7639..2760825e53fa 100644 --- a/net/Kconfig +++ b/net/Kconfig @@ -403,6 +403,15 @@ config NET_DEVLINK infrastructure to support access to physical chip-wide config and monitoring. +config MAY_USE_DEVLINK + tristate + default m if NET_DEVLINK=m + default y if NET_DEVLINK=y || NET_DEVLINK=n + help + Drivers using the devlink infrastructure should have a dependency + on MAY_USE_DEVLINK to ensure they do not cause link errors when + devlink is a loadable module and the driver using it is built-in. + endif # if NET # Used by archs to tell that they support BPF_JIT
The new NET_DEVLINK infrastructure can be a loadable module, but the drivers using it might be built-in, which causes link errors like: drivers/net/built-in.o: In function `mlx4_load_one': :(.text+0x2fbfda): undefined reference to `devlink_port_register' :(.text+0x2fc084): undefined reference to `devlink_port_unregister' drivers/net/built-in.o: In function `mlxsw_sx_port_remove': :(.text+0x33a03a): undefined reference to `devlink_port_type_clear' :(.text+0x33a04e): undefined reference to `devlink_port_unregister' There are multiple ways to avoid this: a) add 'depends on NET_DEVLINK || !NET_DEVLINK' dependencies for each user b) use 'select NET_DEVLINK' from each driver that uses it and hide the symbol in Kconfig. c) make NET_DEVLINK a 'bool' option so we don't have to list it as a dependency, and rely on the APIs to be stubbed out when it is disabled d) use IS_REACHABLE() rather than IS_ENABLED() to check for NET_DEVLINK in include/net/devlink.h This implements a variation of approach a) by adding an intermediate symbol that drivers can depend on, and changes the three drivers using it. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 09d4d087cd48 ("mlx4: Implement devlink interface") Fixes: c4745500e988 ("mlxsw: Implement devlink interface") --- drivers/infiniband/hw/mlx4/Kconfig | 1 + drivers/net/ethernet/mellanox/mlx4/Kconfig | 1 + drivers/net/ethernet/mellanox/mlxsw/Kconfig | 1 + net/Kconfig | 9 +++++++++ 4 files changed, 12 insertions(+)