This resolves race during initialization where the resources with
ops are registered before driver and the structures used by occ_get
op is initialized. So keep occ_get callbacks registered only when
all structs are initialized.
The example flows, as it is in mlxsw:
1) driver load/asic probe:
mlxsw_core
-> mlxsw_sp_resources_register
-> mlxsw_sp_kvdl_resources_register
-> devlink_resource_register IDX
mlxsw_spectrum
-> mlxsw_sp_kvdl_init
-> mlxsw_sp_kvdl_parts_init
-> mlxsw_sp_kvdl_part_init
-> devlink_resource_size_get IDX (to get the current setup
size from devlink)
-> devlink_resource_occ_get_register IDX (register current
occupancy getter)
2) reload triggered by devlink command:
-> mlxsw_devlink_core_bus_device_reload
-> mlxsw_sp_fini
-> mlxsw_sp_kvdl_fini
-> devlink_resource_occ_get_unregister IDX
(struct mlxsw_sp *mlxsw_sp is freed at this point, call to occ get
which is using mlxsw_sp would cause use-after free)
-> mlxsw_sp_init
-> mlxsw_sp_kvdl_init
-> mlxsw_sp_kvdl_parts_init
-> mlxsw_sp_kvdl_part_init
-> devlink_resource_size_get IDX (to get the current setup
size from devlink)
-> devlink_resource_occ_get_register IDX (register current
occupancy getter)
Fixes: d9f9b9a4d0 ("devlink: Add support for resource abstraction")
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The __net_initdata section cannot currently be used for structures that
get cleaned up in an exitcall using unregister_pernet_operations:
WARNING: vmlinux.o(.text+0x868c34): Section mismatch in reference from the function nsim_devlink_exit() to the (unknown reference) .init.data:(unknown)
The function nsim_devlink_exit() references
the (unknown reference) __initdata (unknown).
This is often because nsim_devlink_exit lacks a __initdata
annotation or the annotation of (unknown) is wrong.
WARNING: vmlinux.o(.text+0x868c64): Section mismatch in reference from the function nsim_devlink_init() to the (unknown reference) .init.data:(unknown)
WARNING: vmlinux.o(.text+0x8692bc): Section mismatch in reference from the function nsim_fib_exit() to the (unknown reference) .init.data:(unknown)
WARNING: vmlinux.o(.text+0x869300): Section mismatch in reference from the function nsim_fib_init() to the (unknown reference) .init.data:(unknown)
As that warning tells us, discarding the structure after a module is
loaded would lead to a undefined behavior when that module is removed.
It might be possible to change that annotation so it has no effect for
loadable modules, but I have not figured out exactly how to do that, and
we want this to be fixed in -rc1.
This just removes the annotations, just like we do for all other such
modules.
Fixes: 37923ed6b8 ("netdevsim: Add simple FIB resource controller via devlink")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Change nsim_devlink_setup to return any error back to the caller and
update nsim_init to handle it.
Requested-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add devlink support to netdevsim and use it to implement a simple,
profile based resource controller. Only one controller is needed
per namespace, so the first netdevsim netdevice in a namespace
registers with devlink. If that device is deleted, the resource
settings are deleted.
The resource controller allows a user to limit the number of IPv4 and
IPv6 FIB entries and FIB rules. The resource paths are:
/IPv4
/IPv4/fib
/IPv4/fib-rules
/IPv6
/IPv6/fib
/IPv6/fib-rules
The IPv4 and IPv6 top level resources are unlimited in size and can not
be changed. From there, the number of FIB entries and FIB rule entries
are unlimited by default. A user can specify a limit for the fib and
fib-rules resources:
$ devlink resource set netdevsim/netdevsim0 path /IPv4/fib size 96
$ devlink resource set netdevsim/netdevsim0 path /IPv4/fib-rules size 16
$ devlink resource set netdevsim/netdevsim0 path /IPv6/fib size 64
$ devlink resource set netdevsim/netdevsim0 path /IPv6/fib-rules size 16
$ devlink dev reload netdevsim/netdevsim0
such that the number of rules or routes is limited (96 ipv4 routes in the
example above):
$ for n in $(seq 1 32); do ip ro add 10.99.$n.0/24 dev eth1; done
Error: netdevsim: Exceeded number of supported fib entries.
$ devlink resource show netdevsim/netdevsim0
netdevsim/netdevsim0:
name IPv4 size unlimited unit entry size_min 0 size_max unlimited size_gran 1 dpipe_tables non
resources:
name fib size 96 occ 96 unit entry size_min 0 size_max unlimited size_gran 1 dpipe_tables
...
With this template in place for resource management, it is fairly trivial
to extend and shows one way to implement a simple counter based resource
controller typical of network profiles.
Currently, devlink only supports initial namespace. Code is in place to
adapt netdevsim to a per namespace controller once the network namespace
issues are resolved.
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Jiri Pirko