The max depth of a fastreg mr depends on whether the device supports
DSGL or not.  So compute it dynamically based on the device support
and the module use_dsgl option.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

If kmalloc() fails in c4iw_alloc_ucontext(), the function
leaves but does not set an error code in ret variable:
it will return 0 to the caller.

This patch set ret to -ENOMEM in such case.

Cc: Steve Wise <swise@opengridcomputing.com>
Cc: Steve Wise <swise@chelsio.com>
Signed-off-by: NYann Droneaud <ydroneaud@opteya.com>
Acked-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The current logic suffers from a slow response time to disable user DB
usage, and also fails to avoid DB FIFO drops under heavy load. This commit
fixes these deficiencies and makes the avoidance logic more optimal.
This is done by more efficiently notifying the ULDs of potential DB
problems, and implements a smoother flow control algorithm in iw_cxgb4,
which is the ULD that puts the most load on the DB fifo.

Design:

cxgb4:

Direct ULD callback from the DB FULL/DROP interrupt handler.  This allows
the ULD to stop doing user DB writes as quickly as possible.

While user DB usage is disabled, the LLD will accumulate DB write events
for its queues.  Then once DB usage is reenabled, a single DB write is
done for each queue with its accumulated write count.  This reduces the
load put on the DB fifo when reenabling.

iw_cxgb4:

Instead of marking each qp to indicate DB writes are disabled, we create
a device-global status page that each user process maps.  This allows
iw_cxgb4 to only set this single bit to disable all DB writes for all
user QPs vs traversing the idr of all the active QPs.  If the libcxgb4
doesn't support this, then we fall back to the old approach of marking
each QP.  Thus we allow the new driver to work with an older libcxgb4.

When the LLD upcalls iw_cxgb4 indicating DB FULL, we disable all DB writes
via the status page and transition the DB state to STOPPED.  As user
processes see that DB writes are disabled, they call into iw_cxgb4
to submit their DB write events.  Since the DB state is in STOPPED,
the QP trying to write gets enqueued on a new DB "flow control" list.
As subsequent DB writes are submitted for this flow controlled QP, the
amount of writes are accumulated for each QP on the flow control list.
So all the user QPs that are actively ringing the DB get put on this
list and the number of writes they request are accumulated.

When the LLD upcalls iw_cxgb4 indicating DB EMPTY, which is in a workq
context, we change the DB state to FLOW_CONTROL, and begin resuming all
the QPs that are on the flow control list.  This logic runs on until
the flow control list is empty or we exit FLOW_CONTROL mode (due to
a DB DROP upcall, for example).  QPs are removed from this list, and
their accumulated DB write counts written to the DB FIFO.  Sets of QPs,
called chunks in the code, are removed at one time. The chunk size is 64.
So 64 QPs are resumed at a time, and before the next chunk is resumed, the
logic waits (blocks) for the DB FIFO to drain.  This prevents resuming to
quickly and overflowing the FIFO.  Once the flow control list is empty,
the db state transitions back to NORMAL and user QPs are again allowed
to write directly to the user DB register.

The algorithm is designed such that if the DB write load is high enough,
then all the DB writes get submitted by the kernel using this flow
controlled approach to avoid DB drops.  As the load lightens though, we
resume to normal DB writes directly by user applications.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Adds support for Chelsio T5 adapter.
Enables T5's Write Combining feature.
Signed-off-by: NVipul Pandya <vipul@chelsio.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This allows querying the QP state before flushing.
Signed-off-by: NVipul Pandya <vipul@chelsio.com>
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Using kfifos for ID management was limiting the number of QPs and
preventing NP384 MPI jobs.  So replace it with a simple bitmap
allocator.

Remove IDs from the IDR tables before deallocating them.  This bug was
causing the BUG_ON() in insert_handle() to fire because the ID was
getting reused before being removed from the IDR table.
Signed-off-by: NVipul Pandya <vipul@chelsio.com>
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Signed-off-by: NVipul Pandya <vipul@chelsio.com>
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

The kernel IB stack uses one enumeration for IB speed, which wasn't
explicitly specified in the verbs header file.  Add that enum, and use
it all over the code.

The IB speed/width notation is also used by iWARP and IBoE HW drivers,
which use the convention of rate = speed * width to advertise their
port link rate.
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

These methods don't make sense for iWARP devices, so rather than
forcing them to implement stubs, just return -ENOSYS in the core if
the hardware driver doesn't set .modify_device and/or .modify_port.
Signed-off-by: NRoland Dreier <roland@purestorage.com>

A few more EEH fixes:

c4iw_wait_for_reply(): detect fatal EEH condition on timeout and
return an error.

The iw_cxgb4 driver was only calling ib_deregister_device() on an EEH
event followed by a ib_register_device() when the device was
reinitialized.  However, the RDMA core doesn't allow multiple
iterations of register/deregister by the provider. See
drivers/infiniband/core/sysfs.c: ib_device_unregister_sysfs() where
the kobject ref is held until the device is deallocated in
ib_deallocate_device().  Calling deregister adds this kobj reference,
and then a subsequent register call will generate a WARN_ON() from the
kobject subsystem because the kobject is being initialized but is
already initialized with the ref held.

So the provider must deregister and dealloc when resetting for an EEH
event, then alloc/register to re-initialize.  To do this, we cannot
use the device ptr as our ULD handle since it will change with each
reallocation.  This commit adds a ULD context struct which is used as
the ULD handle, and then contains the device pointer and other state
needed.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

- Remove dsgl support - doesn't work in T4.
- Wrap the immediate PBL as needed when building it in the wr.
- Adjust max pbl depth allowed based on ulptx alignment requirements.
- Bump the slots per SQ to 5 to allow up to 128MB fast registers.
- Advertise fastreg support by default.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

T4 support on-chip SQs to reduce latency.  This patch adds support for
this in iw_cxgb4:

 - Manage ocqp memory like other adapter mem resources.
 - Allocate user mode SQs from ocqp mem if available.
 - Map ocqp mem to user process using write combining.
 - Map PCIE_MA_SYNC reg to user process.

Bump uverbs ABI.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

The LLD now supports proper UP state change events, so move the RDMA
provider registration to UP path.

This fixes a crash when loading iw_cxgb4 _after_ the NFS/RDMA
transport is up and running.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Add a new parameter to ib_register_device() so that low-level device
drivers can pass in a pointer to a callback function that will be
called for each port that is registered in sysfs.  This allows
low-level device drivers to create files in

    /sys/class/infiniband/<hca>/ports/<N>/

without having to poke through the internals of the RDMA sysfs handling.

There is no need for an unregister function since the kobject
reference will go to zero when ib_unregister_device() is called.
Signed-off-by: NRalph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Add an RDMA/iWARP driver for Chelsio T4 Ethernet adapters.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>