mlxsw: spectrum_kvdl: Protect allocations with a lock

The KVDL is used to store objects allocated throughout various places
in the driver. For example, both nexthops (adjacency entries) and ACL
actions are stored in the KVDL.

Currently, all allocations are protected by RTNL, but this is going to
change with the removal of RTNL from the routing code.

Therefore, protect KVDL allocations with a lock. A mutex is used since
the free operation can block in Spectrum-2.

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

mlxsw: Replace zero-length array with flexible-array member

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
int stuff;
struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Tested-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: Replace license text with SPDX identifiers and adjust copyrights

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_kvdl: Pass entry_count to free function

For the Spectrum-2 KVD linear manager implementation, entry_count will be
needed even for the free function. So pass it down.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_kvdl: Pass entry type to alloc/free

Future Spectrum-2 KVD linear manager implementation needs to know type
of the entry to alloc and free. So define the types in an enum and
pass it down to alloc and free functions. Once the entry type
is passed down, KVDL common part knows sizes of each entry types,
so replace size function arg with entry count.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_kvdl: Push out KVD linear management into ops

In Spectrum-2 there is a different implementation of KVD linear
management. Unlike in Spectrum where there is a single index space,
in Spectrum-2 the indexes are per-resource. Also there is need to
explicitly tell HW that an entry is no longer used.
So push out the existing implementation into spectrum1_kvdl.c and
prepare ops infrastructure to allow new implementation in a follow-up.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

devlink: convert occ_get op to separate registration

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: d9f9b9a4d05f ("devlink: Add support for resource abstraction")
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum: Pass mlxsw_core as arg of mlxsw_sp_kvdl_resources_register()

Pass struct mlxsw_core instead of devlink since it is nicer within mlxsw
code and we need both structs in mlxsw_sp_kvdl_resources_register()
anyway.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum: Change KVD linear parts from list to array

The parts info is array. The parts copy this info array, yet they are a
list. So make the indexing according to the id and change the list of
parts into array of parts. This helps to eliminate lookups and
constructs like mlxsw_sp_kvdl_part_update() (took me some non-trivial
time to figure out what is going on there).
Alongside with that, introduce a helper macro to define the parts infos.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: Constify devlink_resource_ops

devlink_resource_ops should be const as the arg of register function is
also const.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_kvdl: Fix handling of resource_size_param

Current code uses global variables, adjusts them and passes pointer down
to devlink. With every other mlxsw_core instance, the previously passed
pointer values are rewritten. Fix this by de-globalize the variables.

Fixes: 7f47b19bd744 ("mlxsw: spectrum_kvdl: Add support for per part occupancy")
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

devlink: Remove top_hierarchy arg to devlink_resource_register

top_hierarchy arg can be determined by comparing parent_resource_id to
DEVLINK_RESOURCE_ID_PARENT_TOP so it does not need to be a separate
argument.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_kvdl: Make some functions static

Fixes the following sparse warnings:

drivers/net/ethernet/mellanox/mlxsw/spectrum_kvdl.c:371:5: warning:
symbol 'mlxsw_sp_kvdl_single_occ_get' was not declared. Should it be static?
drivers/net/ethernet/mellanox/mlxsw/spectrum_kvdl.c:384:5: warning:
symbol 'mlxsw_sp_kvdl_chunks_occ_get' was not declared. Should it be static?
drivers/net/ethernet/mellanox/mlxsw/spectrum_kvdl.c:397:5: warning:
symbol 'mlxsw_sp_kvdl_large_chunks_occ_get' was not declared. Should it be static?

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_kvdl: avoid uninitialized variable warning

gcc warns that 'resource_id' is not initialized if we don't come though
any of the three 'case' statements before:

drivers/net/ethernet/mellanox/mlxsw/spectrum_kvdl.c: In function 'mlxsw_sp_kvdl_part_init':
drivers/net/ethernet/mellanox/mlxsw/spectrum_kvdl.c:275:8: error: 'resource_id' may be used uninitialized in this function [-Werror=maybe-uninitialized]

In the current code, that won't happen, but it's more robust to explicitly
handle this by returning a failure from mlxsw_sp_kvdl_part_init.

Fixes: 887839e6960d ("mlxsw: spectrum_kvdl: Add support for dynamic partition set")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_kvdl: use div_u64() for 64-bit division

Calculating the number of entries now uses 64-bit arithmetic that
causes a link error on 32-bit architectures:

drivers/net/ethernet/mellanox/mlxsw/spectrum_kvdl.o: In function `mlxsw_sp_kvdl_init':
spectrum_kvdl.c:(.text+0x51c): undefined reference to `__aeabi_uldivmod'

We could probably use a 32-bit division here as before, but since this is
not in a performance critical path, div_u64() seems cleaner here.

Fixes: 887839e6960d ("mlxsw: spectrum_kvdl: Add support for dynamic partition set")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_kvdl: Add support for per part occupancy

Add support for calculating occupancy for separate kvdl parts.

Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_kvdl: Add support for dynamic partition set

Add support for dynamic partition set via the resource interface.

Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_kvdl: Add support for linear division resources

The linear part of the KVD memory is sub-divided into multiple parts. This
patch exposes this internal partitions via the resource interface.

Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum: Make function mlxsw_sp_kvdl_part_occ() static

Fixes the following sparse warning:

drivers/net/ethernet/mellanox/mlxsw/spectrum_kvdl.c:289:5: warning:
symbol 'mlxsw_sp_kvdl_part_occ' was not declared. Should it be static?

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum: Add support for getting kvdl occupancy

Add support for getting the kvdl occupancy through the resource interface.

Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum: Add another partition to KVD linear

The KVD linear is currently partitioned into two partitions. One for
single entries and another for groups of 32 entries.

Add another partition consisting of groups of 512 entries which will
allow us to more accurately represent the nexthop weights in non-equal
cost multi-path routing.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum: Add ability to query KVDL allocation size

The current KVDL allocation API allows the user to specify the requested
number of entries, but the user has no way of knowing how many entries
were actually allocated.

This works because existing users (e.g., router) request the exact
number they end up using. With the introduction of large adjacency
groups, this will change, as the router will have the ability to choose
from several allocation sizes, where larger allocations provide higher
accuracy with respect to requested weights and better resilience against
nexthop failures.

One option is to have the router try several allocations of descending
size until one succeeds, but a better way is to simply allow it to query
the actual allocation size and then size its request accordingly.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum: Better represent KVDL partitions

The KVD linear (KVDL) allocator currently consists of a very large
bitmap that reflects the KVDL's usage. The boundaries of each partition
as well as their allocation size are represented using defines.

This representation requires us to patch all the functions that act on a
partition whenever the partitioning scheme is changed. In addition, it
does not enable the dynamic configuration of the KVDL using the
up-coming resource manager.

Add objects to represent these partitions as well as the accompanying
code that acts on them to perform allocations and de-allocations.

In the following patches, this will allow us to easily add another
partition as well as new operations to act on these partitions.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_kvdl: Cosmetic kvdl allocator API change

Currently the return allocated index and err value are multiplexed.
This patch changes the API to decouple the ret value from the allocated
index.

Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: Introduce simplistic KVD linear area manager

This is a very simple manager for KVD linear area. Currently, the
allocator will either allocate a single entry from pre-defined sub-area,
or in case more than one entry is needed, it will allocate 32-entry chunk
in other pre-defined sub-area.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>