This patch implements the device counters create and destroy APIs and
introducing some internal management structures.

Downstream patches in this series will add the functionality to support
flow counters binding and reading.
Reviewed-by: NYishai Hadas <yishaih@mellanox.com>
Signed-off-by: NRaed Salem <raeds@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Adding mlx5_ib driver implementation for reg_dm_mr callback
which allows registering device memory (DM) as an MR for
local and remote access.
Signed-off-by: NAriel Levkovich <lariel@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

This patch adds the mlx5_ib driver implementation for the device
memory allocation API.
It implements the ib_device callbacks for allocation and deallocation
operations as well as a new mmap command support which allows mapping
an allocated device memory to a VMA.

The change also adds reporting of device memory maximum size and
alignment parameters reported in device capabilities.

The allocation/deallocation operations are using new firmware
commands to allocate MEMIC memory on the device.
Signed-off-by: NAriel Levkovich <lariel@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

This commit introduces support for the esp_aes_gcm flow
specification for the Innova device. To that end we add
support for egress steering and some validations that an
IPsec rule is indeed valid.
Signed-off-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NAviad Yehezkel <aviadye@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Adding implementation in mlx5 driver to create and destroy action_xfrm
object. This merely call the accel layer.

A user may pass MLX5_IB_XFRM_FLAGS_REQUIRE_METADATA flag which states
that [s]he expects a metadata header to be added to the payload. This
header represents information regarding the transformation's state.
Reviewed-by: NYishai Hadas <yishaih@mellanox.com>
Signed-off-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NAviad Yehezkel <aviadye@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

In order to have a custom parsing tree, a provider driver needs to
assign its parsing tree to ib_device specs_tree field. Otherwise, the
uverbs client assigns a common default parsing tree for it.
In downstream patches, the mlx5_ib driver gains a custom parsing tree,
which contains both the common objects and a new flags field for the
UVERBS_FLOW_ACTION_ESP_CREATE command.
This patch makes mlx5_ib assign its own tree to specs_root, which
later on will be extended.
Reviewed-by: NYishai Hadas <yishaih@mellanox.com>
Signed-off-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Enable RAW QP to be able to configure burst control by modify_qp. By
using burst control with rate limiting, user can achieve best
performance and accuracy. The burst control information is passed by
user through udata.

This patch also reports burst control capability for mlx5 related
hardwares, burst control is only marked as supported when both
packet_pacing_burst_bound and packet_pacing_typical_size are
supported.
Signed-off-by: NBodong Wang <bodong@mellanox.com>
Reviewed-by: NDaniel Jurgens <danielj@mellanox.com>
Reviewed-by: NYishai Hadas <yishaih@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

On load we create private CQ/QP/PD in order to be used by UMR, we create
those resources after we register ourself as an IB device, and we destroy
them after we unregister as an IB device. This was changed by commit
16c1975f ("IB/mlx5: Create profile infrastructure to add and remove
stages") which moved the destruction before we unregistration. This
allowed to trigger an invalid memory access when unloading mlx5_ib while
there are open resources:

BUG: unable to handle kernel paging request at 00000001002c012c
...
Call Trace:
 mlx5_ib_post_send_wait+0x75/0x110 [mlx5_ib]
 __slab_free+0x9a/0x2d0
 delay_time_func+0x10/0x10 [mlx5_ib]
 unreg_umr.isra.15+0x4b/0x50 [mlx5_ib]
 mlx5_mr_cache_free+0x46/0x150 [mlx5_ib]
 clean_mr+0xc9/0x190 [mlx5_ib]
 dereg_mr+0xba/0xf0 [mlx5_ib]
 ib_dereg_mr+0x13/0x20 [ib_core]
 remove_commit_idr_uobject+0x16/0x70 [ib_uverbs]
 uverbs_cleanup_ucontext+0xe8/0x1a0 [ib_uverbs]
 ib_uverbs_cleanup_ucontext.isra.9+0x19/0x40 [ib_uverbs]
 ib_uverbs_remove_one+0x162/0x2e0 [ib_uverbs]
 ib_unregister_device+0xd4/0x190 [ib_core]
 __mlx5_ib_remove+0x2e/0x40 [mlx5_ib]
 mlx5_remove_device+0xf5/0x120 [mlx5_core]
 mlx5_unregister_interface+0x37/0x90 [mlx5_core]
 mlx5_ib_cleanup+0xc/0x225 [mlx5_ib]
 SyS_delete_module+0x153/0x230
 do_syscall_64+0x62/0x110
 entry_SYSCALL_64_after_hwframe+0x21/0x86
...

We restore the original behavior by breaking the UMR stage into two parts,
pre and post IB registration stages, this way we can restore the original
functionality and maintain clean separation of logic between stages.

Fixes: 16c1975f ("IB/mlx5: Create profile infrastructure to add and remove stages")
Signed-off-by: NMark Bloch <markb@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

The mlx5 driver needs to be able to issue invalidation to ODP MRs
even if it cannot allocate memory. To this end it preallocates
emergency pages to use when the situation arises.

This flow should be extremely rare enough, that we don't need
to worry about contention and therefore a single emergency page
is good enough.
Signed-off-by: NIlya Lesokhin <ilyal@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

This commit adds full support for IB representor:

1) Representors profile, We add two new profiles:
   nic_rep_profile - This profile will be used to create an IB device that
   represents the PF/UPLINK.
   rep_profile - This profile will be used to create an IB device that
   represents VFs. Each VF will be its own representor.
2) Proper load/unload callbacks, Those are called by the E-Switch when
   moving to/from switchdev mode.
3) Different flow DB handling for when we in switchdev mode.
Signed-off-by: NMark Bloch <markb@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

In order to forward traffic from representor's SQ to the right virtual
function, every time an SQ is created also add the corresponding flow rule
to the FDB.
Signed-off-by: NMark Bloch <markb@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

Currently in switchdev mode we allow only for raw packet QPs.
Expose the right capabilities and set the gid table length to 0, also
make sure we don't try to enable RoCE, so split the function
to enable RoCE so representors can enable only the notifier needed for
net device events.
Signed-off-by: NMark Bloch <markb@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

A flow DB is a shared resource between PF and representors,
need to allocate it only when creating the PF IB device.
Once we add IB representors, they will use the flow db which was
created by the PF.
Signed-off-by: NMark Bloch <markb@mellanox.com>
Reviewed-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

Create the basic infrastructure of registering and unregistering
IB representors. The load/unload callbacks are left empty and
proper implementation will be introduced in following patches.
Signed-off-by: NMark Bloch <markb@mellanox.com>
Reviewed-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

The current implementation of create CQ requires contiguous
memory, such requirement is problematic once the memory is
fragmented or the system is low in memory, it causes for
failures in dma_zalloc_coherent().

This patch implements new scheme of fragmented CQ to overcome
this issue by introducing new type: 'struct mlx5_frag_buf_ctrl'
to allocate fragmented buffers, rather than contiguous ones.

Base the Completion Queues (CQs) on this new fragmented buffer.

It fixes following crashes:
kworker/29:0: page allocation failure: order:6, mode:0x80d0
CPU: 29 PID: 8374 Comm: kworker/29:0 Tainted: G OE 3.10.0
Workqueue: ib_cm cm_work_handler [ib_cm]
Call Trace:
[<>] dump_stack+0x19/0x1b
[<>] warn_alloc_failed+0x110/0x180
[<>] __alloc_pages_slowpath+0x6b7/0x725
[<>] __alloc_pages_nodemask+0x405/0x420
[<>] dma_generic_alloc_coherent+0x8f/0x140
[<>] x86_swiotlb_alloc_coherent+0x21/0x50
[<>] mlx5_dma_zalloc_coherent_node+0xad/0x110 [mlx5_core]
[<>] ? mlx5_db_alloc_node+0x69/0x1b0 [mlx5_core]
[<>] mlx5_buf_alloc_node+0x3e/0xa0 [mlx5_core]
[<>] mlx5_buf_alloc+0x14/0x20 [mlx5_core]
[<>] create_cq_kernel+0x90/0x1f0 [mlx5_ib]
[<>] mlx5_ib_create_cq+0x3b0/0x4e0 [mlx5_ib]
Signed-off-by: NYonatan Cohen <yonatanc@mellanox.com>
Reviewed-by: NTariq Toukan <tariqt@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

The flags field the enum is used with comes directly from the uapi
so it belongs in the uapi headers for clarity and so userspace can
use it.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

This patch maps the new page to user space applications to
allow converting a user space completion timestamp to system wall
time at the lowest possible latency cost.
By using a versioning scheme we allow compatibility between current
and future userspace libraries.
The change moves mlx5_ib_mmap_cmd enum from mlx5_ib.h to the
abi header file mlx5-abi.h.
Reviewed-by: NAlex Vesker <valex@mellanox.com>
Reviewed-by: NYishai Hadas <yishaih@mellanox.com>
Signed-off-by: NFeras Daoud <ferasda@mellanox.com>
Signed-off-by: NEitan Rabin <rabin@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Update the counter interface for multiple ports. Some counter sets
always comes from the primary device.

Port specific counters should be accessed per mlx5_core_dev not always
through the IB master mdev.
Signed-off-by: NDaniel Jurgens <danielj@mellanox.com>
Signed-off-by: NParav Pandit <parav@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

When there are multiple ports for single IB(RoCE) device, support
debugfs entries to be available for each port.
Signed-off-by: NParav Pandit <parav@mellanox.com>
Signed-off-by: NDaniel Jurgens <danielj@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

When mlx5_ib_add is called determine if the mlx5 core device being
added is capable of dual port RoCE operation. If it is, determine
whether it is a master device or a slave device using the
num_vhca_ports and affiliate_nic_vport_criteria capabilities.

If the device is a slave, attempt to find a master device to affiliate it
with. Devices that can be affiliated will share a system image guid. If
none are found place it on a list of unaffiliated ports. If a master is
found bind the port to it by configuring the port affiliation in the NIC
vport context.

Similarly when mlx5_ib_remove is called determine the port type. If it's
a slave port, unaffiliate it from the master device, otherwise just
remove it from the unaffiliated port list.

The IB device is registered as a multiport device, even if a 2nd port is
not available for affiliation. When the 2nd port is affiliated later the
GID cache must be refreshed in order to get the default GIDs for the 2nd
port in the cache. Export roce_rescan_device to provide a mechanism to
refresh the cache after a new port is bound.

In a multiport configuration all IB object (QP, MR, PD, etc) related
commands should flow through the master mlx5_core_dev, other commands
must be sent to the slave port mlx5_core_mdev, an interface is provide
to get the correct mdev for non IB object commands.
Signed-off-by: NDaniel Jurgens <danielj@mellanox.com>
Reviewed-by: NParav Pandit <parav@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

When multiple RoCE ports are supported registration for events on
multiple netdevs is required. Refactor the event registration and
handling to support multiple ports.
Signed-off-by: NDaniel Jurgens <danielj@mellanox.com>
Reviewed-by: NParav Pandit <parav@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

A DC Target (DCT) QP is represented in the hardware as a unique object.
This object is created by CREATE_DCT command and destroyed by DESTROY_DCT
command. However, in the driver we describe it as a QP.

The hardware command that creates a DCT needs parameters that the verb
create_qp() does not provide. Those remaining parameters are provided
with the call to the verb modify_qp(). Therefore we delay the actual
creation of a DCT in the hardware until the stage of modify_qp() to RTR.

A support for query_qp() was added as well. It uses QUERY_DCT command to
retrieve the applicable fields.
Signed-off-by: NMoni Shoua <monis@mellanox.com>
Reviewed-by: NYishai Hadas <yishaih@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The QP type IB_QPT_DRIVER doesn't describe the transport or the service
that the QP provides but those are known only to the hardware driver.
The actual type of the QP is stored in the hardware driver context (i.e.
mlx5_qp) under the field qp_sub_type.

Take the real QP type and any extra data that is required to create the QP
from the driver channel and modify the QP initial attributes before continuing
with create_qp().

Downstream patches from this series will add support for both DCI and
DCT driver QPs.
Signed-off-by: NMoni Shoua <monis@mellanox.com>
Reviewed-by: NYishai Hadas <yishaih@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Unconditional locks/list and ODP srcu initialization should be done in
the INIT stage. Remove those from the CAPS stage and move them to the
proper stage.
Signed-off-by: NMark Bloch <markb@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The loopback stage only initializes a lock, move it to be in
the CAPS initialization phase and get rid loopback step completely.
Signed-off-by: NMark Bloch <markb@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Today we have single function which is used when we add an IB interface,
break this function into multiple functions.

Create stages and a generic mechanism to execute each stage.
This is in preparation for RDMA/IB representors which might not need
all stages or will do things differently in some of the stages.

This patch doesn't change any functionality.
Signed-off-by: NMark Bloch <markb@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

This patch enables QP creation with a given BF index, this allows the
user space driver to share same BF between few QPs or alternatively have
a dedicated BF per QP.
Signed-off-by: NYishai Hadas <yishaih@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

This patch exposes the option to dynamic allocates a UAR, this
functionality will be used in downstream patch in this series as
part of QP creation.

Specifically, the user space driver asks for a UAR allocation in a given
page index, upon success this UAR and its bfregs can be used as part of
QP creation by the user space driver.

To enable allocating more than 256 UARs the page index is encoded in an
extra one byte just after the command byte.
Signed-off-by: NYishai Hadas <yishaih@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

This patch extends the alloc context flow to be prepared for working
with dynamic UAR allocations.

Currently upon alloc context there is some fix size of UARs that are
allocated (named 'static allocation') and there is no option to user
application to ask for more or control which UAR will be used by which
QP.

In this patch the driver prepares its data structures to manage both the
static and the dynamic allocations and let the user driver knows about
the max value of dynamic blue-flame registers that are allowed.

Downstream patches from this series will enable the dynamic allocation
and the association as part of QP creation.
Signed-off-by: NYishai Hadas <yishaih@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

User-space applications can do mmap and munmap directly at
any time.

Since the VMA list is not protected with a mutex, concurrent
accesses to the VMA list from the mmap and munmap can cause
data corruption. Add a mutex around the list.

Cc: <stable@vger.kernel.org> # v4.7
Fixes: 7c2344c3 ("IB/mlx5: Implements disassociate_ucontext API")
Reviewed-by: NYishai Hadas <yishaih@mellanox.com>
Signed-off-by: NMajd Dibbiny <majd@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Add the PCI write end padding flag to device_cap_flags enum and set it
during mlx5_ib_query_device so it will be reported to user-space.

During WQ/QP creation, set that capability for WQ/QP if user requested
it and HW supports it.

PCI write end padding modification is not supported for now. There's no
such flag for a QP but for a WQ, create and modify use the same flag.
Return an error if PCI write end padding flag is set during modify_wq.
Signed-off-by: NNoa Osherovich <noaos@mellanox.com>
Reviewed-by: NMajd Dibbiny <majd@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

The device can support receive Stateless Offloads for the inner
packet's fields only when the packet is processed by TIR which is
enabled to support tunneling. Otherwise, the device treats the
packet as an ordinary non-tunneling packet and receive offloads
can be done only for the outer packet's field.
In order to enable receive Stateless Offloading support for incoming
tunneling traffic the TIR should be created with tunneled_offload_en.
Tunneling offloads is supported only be raw ethernet QP.

This patch includes:
* New QP creation flag for tunneling offloads.
* Reports device capabilities.
Signed-off-by: NMaor Gottlieb <maorg@mellanox.com>
Reviewed-by: NMark Bloch <markb@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

In some benchmarks and some CPU architectures, writing the CQE on a full
cache line size improves performance by saving memory access operations
(read-modify-write) relative to partial cache line change. This patch
lets the user to configure the device to pad the CQE up to 128B in case
its content is less than 128B. Currently the driver supports only padding
for a CQE size of 128B.
Signed-off-by: NGuy Levi <guyle@mellanox.com>
Reviewed-by: NMark Bloch <markb@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Allow creation of a multi-packet receive queue.

In order to create a multi-packet RQ, the following fields in
the mlx5_ib_rwq should be set:
- log_num_strides: Log of number of strides per WQE
- single_stride_log_num_of_bytes: Log of a single stride size
- two_byte_shift_en: When enabled, hardware pads 2 bytes of zeros
  before writing the message to memory (e.g. for the IP alignment).
Signed-off-by: NNoa Osherovich <noaos@mellanox.com>
Reviewed-by: NMajd Dibbiny <majd@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

This patch reports the device's striding RQ capabilities to
the user-space:
- min/max_single_stride_log_num_of_bytes: Log of min/max number of
  bytes in a single stride.
- min/max_single_wqe_log_num_of_strides: Log of min/max number of
  strides in a single WQE.
- supported_qpts: A bit mask to know which QP types support multi-
  packet RQ, for now only Raw Packet QPs.
Signed-off-by: NNoa Osherovich <noaos@mellanox.com>
Reviewed-by: NMajd Dibbiny <majd@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Provide driver specific values for XRQ capabilities.
Signed-off-by: NArtemy Kovalyov <artemyko@mellanox.com>
Reviewed-by: NYossi Itigin <yosefe@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

This patch is the first step in decoupling UMR usage and
allocation from the MR cache. The only functional change
in this patch is to enables UMR for MRs created with
reg_create.

This change fixes a bug where ODP memory regions that
were not allocated from the MR cache did not have UMR
enabled.
Signed-off-by: NIlya Lesokhin <ilyal@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Allow user space applications to accelerate send and receive
traffic which is typically handled by IPoIB ULP by creating
a UD QP with a given source QPN of the IPoIB UD QP.

UD QP with a given source QPN should basically be similar to
RAW QP from point of view of its created resources.

However,
- Its TIS should point to the source QPN.
- Modify can be done only on its state as the transport attributes
  are managed by its source QP.

This patch manages below:
- Creating/destroying/modifying UD QP with a given source QPN.
Signed-off-by: NYishai Hadas <yishaih@mellanox.com>
Reviewed-by: NMaor Gottlieb <maorg@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Add debugfs interface for monitor the number of delay drop timeout
events and the number of existing dropless RQs in the system.

In addition add debugfs interface for configuring the global timeout value
which is used in the SET_DELAY_DROP command.
Signed-off-by: NMaor Gottlieb <maorg@mellanox.com>
Reviewed-by: NYishai Hadas <yishaih@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

RQs that were configured for "delay drop" will prevent packet drops
when their WQEs are depleted.
Marking an RQ to be drop-less is done by setting delay_drop_en in RQ
context using CREATE_RQ command.

Since this feature is globally activated/deactivated by using the
SET_DELAY_DROP command on all the marked RQs, we activated/deactivated
it according to the number of RQs with 'delay_drop' enabled.

When timeout is expired, then the feature is deactivated. Therefore
the driver handles the delay drop timeout event and reactivate it.
Signed-off-by: NMaor Gottlieb <maorg@mellanox.com>
Reviewed-by: NYishai Hadas <yishaih@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NDoug Ledford <dledford@redhat.com>