net: mellanox: add DEVLINK dependencies

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")
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/infiniband/hw/mlx4/Kconfig b/drivers/infiniband/hw/mlx4/Kconfig
index fc01deac1d3c77497189fc5580ed6a61e9d5ced9..db4aa13ebae0c693138bdb51832961e2a1d492ba 100644 (file)
--- 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 1486ce902a561e498a10bcccf208d869559a7ed1..9ca3734ebb6b84fdb5e58c0def6c461ed924ba5b 100644 (file)
--- 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 ce26adcb4988171fc5e1c81712fb5c6055fe689c..2ad7f67854d5ceda3e4234244d809314f8b71932 100644 (file)
--- 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 6c9cfb0d763926af284df24c4916bbbd72a5265a..2760825e53fa4e2404571d34c98c965e2b46b9cb 100644 (file)
--- 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