When an EMAD is transmitted, a timeout work item is scheduled with a
delay of 200ms, so that another EMAD will be retried until a maximum of
five retries.

In certain situations, it's possible for the function waiting on the
EMAD to be associated with a work item that is queued on the same
workqueue (`mlxsw_core`) as the timeout work item. This results in
flushing a work item on the same workqueue.

According to commit e159489b ("workqueue: relax lockdep annotation
on flush_work()") the above may lead to a deadlock in case the workqueue
has only one worker active or if the system in under memory pressure and
the rescue worker is in use. The latter explains the very rare and
random nature of the lockdep splats we have been seeing:

[   52.730240] ============================================
[   52.736179] WARNING: possible recursive locking detected
[   52.742119] 4.14.0-rc3jiri+ #4 Not tainted
[   52.746697] --------------------------------------------
[   52.752635] kworker/1:3/599 is trying to acquire lock:
[   52.758378]  (mlxsw_core_driver_name){+.+.}, at: [<ffffffff811c4fa4>] flush_work+0x3a4/0x5e0
[   52.767837]
               but task is already holding lock:
[   52.774360]  (mlxsw_core_driver_name){+.+.}, at: [<ffffffff811c65c4>] process_one_work+0x7d4/0x12f0
[   52.784495]
               other info that might help us debug this:
[   52.791794]  Possible unsafe locking scenario:
[   52.798413]        CPU0
[   52.801144]        ----
[   52.803875]   lock(mlxsw_core_driver_name);
[   52.808556]   lock(mlxsw_core_driver_name);
[   52.813236]
                *** DEADLOCK ***
[   52.819857]  May be due to missing lock nesting notation
[   52.827450] 3 locks held by kworker/1:3/599:
[   52.832221]  #0:  (mlxsw_core_driver_name){+.+.}, at: [<ffffffff811c65c4>] process_one_work+0x7d4/0x12f0
[   52.842846]  #1:  ((&(&bridge->fdb_notify.dw)->work)){+.+.}, at: [<ffffffff811c65c4>] process_one_work+0x7d4/0x12f0
[   52.854537]  #2:  (rtnl_mutex){+.+.}, at: [<ffffffff822ad8e7>] rtnl_lock+0x17/0x20
[   52.863021]
               stack backtrace:
[   52.867890] CPU: 1 PID: 599 Comm: kworker/1:3 Not tainted 4.14.0-rc3jiri+ #4
[   52.875773] Hardware name: Mellanox Technologies Ltd. "MSN2100-CB2F"/"SA001017", BIOS 5.6.5 06/07/2016
[   52.886267] Workqueue: mlxsw_core mlxsw_sp_fdb_notify_work [mlxsw_spectrum]
[   52.894060] Call Trace:
[   52.909122]  __lock_acquire+0xf6f/0x2a10
[   53.025412]  lock_acquire+0x158/0x440
[   53.047557]  flush_work+0x3c4/0x5e0
[   53.087571]  __cancel_work_timer+0x3ca/0x5e0
[   53.177051]  cancel_delayed_work_sync+0x13/0x20
[   53.182142]  mlxsw_reg_trans_bulk_wait+0x12d/0x7a0 [mlxsw_core]
[   53.194571]  mlxsw_core_reg_access+0x586/0x990 [mlxsw_core]
[   53.225365]  mlxsw_reg_query+0x10/0x20 [mlxsw_core]
[   53.230882]  mlxsw_sp_fdb_notify_work+0x2a3/0x9d0 [mlxsw_spectrum]
[   53.237801]  process_one_work+0x8f1/0x12f0
[   53.321804]  worker_thread+0x1fd/0x10c0
[   53.435158]  kthread+0x28e/0x370
[   53.448703]  ret_from_fork+0x2a/0x40
[   53.453017] mlxsw_spectrum 0000:01:00.0: EMAD retries (2/5) (tid=bf4549b100000774)
[   53.453119] mlxsw_spectrum 0000:01:00.0: EMAD retries (5/5) (tid=bf4549b100000770)
[   53.453132] mlxsw_spectrum 0000:01:00.0: EMAD reg access failed (tid=bf4549b100000770,reg_id=200b(sfn),type=query,status=0(operation performed))
[   53.453143] mlxsw_spectrum 0000:01:00.0: Failed to get FDB notifications

Fix this by creating another workqueue for EMAD timeouts, thereby
preventing the situation of a work item trying to flush a work item
queued on the same workqueue.

Fixes: caf7297e ("mlxsw: core: Introduce support for asynchronous EMAD register access")
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Reported-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

'trans->tid' is only assigned later in the function, resulting in a zero
transaction ID. Use 'tid' instead.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We currently hard code the maximum number of ports in the driver, but
this may change in future devices, so query it from the firmware
instead.

Fallback to a maximum of 64 ports in case this number can't be queried.
This should only happen in SwitchX-2 for which this number is correct.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We don't use it during development and we can't extend it either, so
remove it.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We always use zero delay before queueing a work on the ordered workqueue
('mlxsw_owq'), so use work_struct directly instead of delayable work.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We're going to start processing FIB entries addition / deletion events
in deferred work. These work items must be processed in the order they
were submitted or otherwise we can have differences between the kernel's
FIB table and the device's.

Solve this by creating an ordered workqueue to which these work items
will be submitted to. Note that we can't simply convert the current
workqueue to be ordered, as EMADs re-transmissions are also processed in
deferred work.

Later on, we can migrate other work items to this workqueue, such as FDB
notification processing and nexthop resolution, since they all take the
same lock anyway.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We call bus->init() before allocating 'lag.mapping'. Change the order of
operations in removal path to reflect that.

This makes the error path of mlxsw_core_bus_device_register() symmetric
with mlxsw_core_bus_device_unregister().
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Without this rollback, the thermal zone is still registered during the
error path, whereas its private data is freed upon the destruction of
the underlying bus device due to the use of devm_kzalloc(). This results
in use after free.

Fix this by calling mlxsw_thermal_fini() from the appropriate place in
the error path.

Fixes: a50c1e35 ("mlxsw: core: Implement thermal zone")
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, the emad trap init was done in the core. In the future we will
want to add some changes to the traps groups, according to device type.
This commit create a driver function to create the trap group for the
emad, so later it can be changed by devices. It also changes the emad
registration to use the new generic functions.
Signed-off-by: NNogah Frankel <nogahf@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Change trap setting function so instead of determining the trap group by
trap id, it gets it as a parameter (so later we can have different trap
groups for Spectrum and Switchx2).
Add "is_ctrl" parameter to the trap setting function. It control whether
the trapped packets wait in a designated control buffer or in their
default one. This parameter is ignored by Switchx2 and Switchib.
Add these parameters to the traps array in Spectrum, Switchx2 and
Switchib.
Signed-off-by: NNogah Frankel <nogahf@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We have 2 types of HW traps to handle, rx traps and events.
The registration workflow for both is very similar. So it only make
sense to create one function to handle both.

This patch creates a struct to hold the data for both cases. It also
creates a registration and an un-registration functions that get this
generic struct as input.
Signed-off-by: NNogah Frankel <nogahf@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement thermal zone for mlxsw based HW. It uses temperature sensor
provided by ASIC (the same as mlxsw hwmon interface) to report current
temp to thermal core. The ASIC's PWM is then used to control speed
of system fans registered as cooling devices.
Signed-off-by: NIvan Vecera <cera@cera.cz>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We are going to add a minimal driver on top of the mlxsw core
infrastructure, which will be mainly used for hardware monitoring in
Baseboard management controller (BMC) installations.

Unlike the switch drivers (e.g., spectrum, switchx2), this driver does not
initialize the ASIC and therefore doesn't need to implement the init() and
fini() methods in its 'mlxsw_driver' struct.
Signed-off-by: NVadim Pasternak <vadimp@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The mlxsw core infrastructure currently assumes that communication with
the ASIC is always possible using Ethernet management datagrams (EMADs),
but this is only possible when the PCI bus is used.

The bus capability flag is added to indicate EMAD support and make core
initialize EMAD communication only when it's set. Otherwise, register
access is done using command interface.
Signed-off-by: NVadim Pasternak <vadimp@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add "port_type_set" API to mlxsw core. The core layer send the change type
callback to the port along with it's private information.
Signed-off-by: NElad Raz <eladr@mellanox.com>
Reviewed-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since we are about to introduce IB port APIs, we will add prefixes to
existing APIs.
Signed-off-by: NElad Raz <eladr@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, devlink register/unregister is done directly from
spectrum/switchx2 port create/remove functions. With a need to
introduce a port type change, the devlink port instances have to be
persistent across type changes, therefore across port create/remove
function calls. So do a bit of reshuffling to achieve that.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NElad Raz <eladr@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

So far, mlxsw_pci.ko is the module that registers PCI table for all
drivers (spectrum and switchx2). That is problematic for example with
dracut. Since mlxsw_spectrum.ko and mlxsw_switchx2.ko are loaded
dynamically from within mlxsw_core.ko, dracut does not have track of
them and avoids them from being included in initramfs.

So make this in an ordinary way and define the PCI tables in individual
driver modules, so it can be properly loaded and included in dracut
initramfs image. As a side effect, this patch could remove no longer
necessary driver "kind" strings which were used to link PCI ids with
individual mlxsw drivers.
Suggested-by: NIvan Vecera <ivecera@redhat.com>
Tested-by: NIvan Vecera <ivecera@redhat.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NIvan Vecera <ivecera@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since the number of resources is going to get much bigger, ease up the
addition by simly defining IDs. Convert the existing structure members
to a set array, one for validity, one for values. Introduce a set of
getters and setters for easy access.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use max lag and max ports in lag resources as the result of resource query
instead of using const to save them.
Signed-off-by: NNogah Frankel <nogahf@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add resources query implementation. If exists, query the HW for its
builtin resources instead of having them as consts in the code.
Signed-off-by: NNogah Frankel <nogahf@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Trace EMAD messages going down to HW and up from HW. Devlink needs to be
registered before EMAD init so the trace function can be called
with valid devlink handle.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
v1->v2:
- Use trace_devlink_hwmsg directly
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

alloc_workqueue replaces deprecated create_workqueue().

A dedicated workqueue has been used since the workqueue
mlxsw_wq is used for FDB notif. processing with workitems that are
involved in normal device operation && because it's a network device
which can be depended upon during memory reclaim.

Workitems &trans->timeout_dw and &mlxsw_sp->fdb_notify.dw,
map to mlxsw_sp_fdb_notify_work (processes FDB notifications from the
underlying device and resolves the netdev to which the entry points to
and notifies the bridge using the switchdev notifier) and
mlxsw_emad_trans_timeout_work (provides async EMAD register access)
respectively. They require forward progress under memory pressure and
hence, WQ_MEM_RECLAIM has been set.

Since there are only a fixed number of work items, explicit concurrency
limit is unnecessary here.
Signed-off-by: NBhaktipriya Shridhar <bhaktipriya96@gmail.com>
Tested-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

So far it was possible to have one EMAD register access at a time,
locked by mutex. This patch extends this interface to allow multiple
EMAD register accesses to be in fly at once. That allows faster
processing on firmware side avoiding unused time in between EMADs.
Measured speedup is ~30% for shared occupancy snapshot operation.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Follow-up patch is going to need to use delayed work as well and
frequently. The FDB notification processing is already using that and
also quite frequently. It makes sense to create separate workqueue just
for mlxsw driver in this case and do not pollute system_wq.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add middle layer in mlxsw core code to forward shared buffer occupancy
calls into specific ASIC drivers.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add middle layer in mlxsw core code to forward shared buffer calls
into specific ASIC drivers.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of that, pass mlxsw_core and use a helper to get driver priv
from driver code. Looks much cleaner that way.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of passing around driver priv, pass struct mlxsw_core *
directly.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove devlink port reg/unreg from spectrum and switchx2 code and rather
do the common work in core. That also ensures code separation where
devlink is only used in core.c.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add middle layer in mlxsw core code to forward port split/unsplit calls
into specific ASIC drivers.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement newly introduced devlink interface. Add devlink port instances
for every port and set the port types accordingly.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

KASan reported use-after-free for the hwmon structure. So fix this by
using devm_kzalloc and let the core take care about freeing the memory
during device dettach.
Reported-by: NIdo Schimmel <idosch@mellanox.com>
Fixes: 89309da3 ("mlxsw: core: Implement temperature hwmon interface")
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Lower layer (pci) has information if the packet is received via LAG port.
If that is the case, it fills up rx_info accordingly. However upper
layer does not care about lag_id/port_index for received packets so
convert it to local_port before passing it up. For that conversion, lag
mapping array is introduced. Upper layer is responsible for setting up
the mapping according to what is set in HW.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ASIC provides access to temperature sensors. Implement their exposure to
userspace using hwmon.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fixes those places where checkpatch complains that comparisons
should place the constant on the right side of the test.
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The Host Trap Group Table (HTGT) register configures trap groups, which
are populated with trap IDs using the Host PacKet Trap (HPKT) register.
However, a trap ID can only be present inside one trap group (the last
configured).

Instead of passing both the trap group and ID for the function that
packs HPKT, pass only the trap ID and derive from it the trap group.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Be symmetric with mlxsw_emad_init and don't use EMADs in mlxsw_emad_fini
cleanup function. Use command interface instead.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Under certain conditions EMAD responses can be returned from the device
even before setting trans_active. This will cause the EMAD Rx listener
to drop the EMAD response - as there are no active transactions - and
timeouts will be generated.

Fix this by setting trans_active before transmitting the EMAD skb.

Fixes: 4ec14b76 ("mlxsw: Add interface to access registers and process events")
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When transmit fails, it is an error, not a warning.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NElad Raz <eladr@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>