accel/habanalabs: Remove unnecessary braces from if statement

The coding style in the Linux kernel prefers not to use
braces for single-statement if conditions.
This patch removes the unnecessary braces from an if statement
in the file drivers/accel/habanalabs/common/command_submission.c,
which also resolves a coding style warning.

Signed-off-by: Malkoot Khan <engr.mkhan1990@gmail.com>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

accel/habanalabs: fix bug in decoder wait for cs completion

The decoder interrupts are handled in the interrupt context
same as all user interrupts.
In such case, the wait list should be protected by
spin_lock_irqsave in order to avoid deadlock that might happen
with the user submission flow.

Signed-off-by: farah kassabri <fkassabri@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

accel/habanalabs: remove leftover code

This code was added as part of a bigger feature which was never
upstreamed, so remove this code.

Signed-off-by: Oded Gabbay <ogabbay@kernel.org>
Reviewed-by: Ofir Bitton <obitton@habana.ai>

accel/habanalabs: remove unused field

flags in struct wait_interrupt_data is not used anywhere so remove it.

Signed-off-by: Oded Gabbay <ogabbay@kernel.org>
Reviewed-by: Ofir Bitton <obitton@habana.ai>

accel/habanalabs: split user interrupts pending list

Currently driver maintain one list for both pending user interrupts
which seeks to wait till CQ reaches it's target value and also the ones
that seeks to get timestamp records when the CQ reaches it's target
value.
This causes delay in handling the waiters which gets higher priority
than the timestamp records.
In order to solve this, let's split the list into two,
one for each case and each one is protected by it's own spinlock.
Waiters will be handled within the interrupt context first,
then the timestamp records will be set.
Freeing the timestamp related memory will be handled in a workqueue.

Signed-off-by: farah kassabri <fkassabri@habana.ai>
Reviewed-by: Tomer Tayar <ttayar@habana.ai>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

accel/habanalabs: optimize timestamp registration handler

Currently we use dynamic allocation inside the irq handler
in order to allocate free node to be used for the free jobs.

This operation is expensive, especially when we deal with large
burst of events records that get released at the same time.

The alternative is to have pre allocated pool of free nodes
and just fetch nodes from this pool at irq handling time instead
of allocating them.

In case the pool becomes full, then the driver will fallback to
dynamic allocations.

As part of the optimization also update the unregister flow
upon re-using a timestamp record, by making the operation much
simpler and quicker. We already have the record in the registration
flow and now we just seek to re-use with different interrupt.
Therefore, no need to look for buffer according to the user handle.

Signed-off-by: farah kassabri <fkassabri@habana.ai>
Reviewed-by: Tomer Tayar <ttayar@habana.ai>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

accel/habanalabs: Move ioctls to the device specific ioctls range

To use drm_ioctl(), move the ioctls to the device specific ioctls
range at [DRM_COMMAND_BASE, DRM_COMMAND_END).

Signed-off-by: Tomer Tayar <ttayar@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

accel/habanalabs: fix wait_for_interrupt abortion flow

When the driver needs to abort waiters for interrupts, for cases
such as critical events that occur and driver need to do hard reset,
in such scenario the driver will complete the fence to wake up the
waiting thread, and will set the fence error indication.
The return value of the completion API will be greater than 0
since it will return the timeout, but as this indicates successful
completion, the driver should mark it as aborted.

Signed-off-by: farah kassabri <fkassabri@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

accel/habanalabs: Allow single timestamp registration request at a time

Protect against concurrency of user requesting to register a timestamp
offset (where the driver fills the timestamp when the command submission
has finished executing) to a specific user interrupt ID. The
protection is basically to allow only one timestamp registration
request to be handled at a time.

This is needed because the user can decide to re-use a timestamp
offset (register an already registered offset, to a different
interrupt ID). This means the request will cause the timestamp node to
move from one interrupt list to another interrupt list. In such
scenario, without proper protection, we could end up adding the same
node twice to the interrupts wait lists.

Signed-off-by: farah kassabri <fkassabri@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

accel/habanalabs: remove support for mmu disable

As mmu disable mode is only used for bring-up stages, let's remove this
option and all code related to it.

Signed-off-by: Ofir Bitton <obitton@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

accel/habanalabs: print max timeout value on CS stuck

If a workload got stuck, we print an error to the kernel log about it.
Add to that print the configured max timeout value, as that value is
not fixed between ASICs and in addition it can be configured using
a kernel module parameter.

Signed-off-by: Oded Gabbay <ogabbay@kernel.org>
Reviewed-by: Ofir Bitton <obitton@habana.ai>

accel/habanalabs: refactor abort of completions and waits

Aborting CS completions should be in command_submission.c but aborting
waiting for user interrupts should be in device.c.

This separation is also for adding more abort operations in the future.

Signed-off-by: Koby Elbaz <kelbaz@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

accel/habanalabs: minimize encapsulation signal mutex lock time

Sync Stream Encapsulated Signal Handlers can be managed from different
contexts, and as such they are protected via a spin_lock.
However, spin_lock was unnecessarily protecting a larger code section
than really needed, covering a sleepable code section as well.
Since spin_lock disables preemption, it could lead to sleeping in
atomic context.

Signed-off-by: Koby Elbaz <kelbaz@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

accel/habanalabs: add uapi to stall/resume engine

The user might want to stall/resume engines to perform power testing
for various scenarios. Because our current
HL_CS_FLAGS_ENGINE_CORE_COMMAND command only handles the engines' cores,
we need to add another opcode for handling entire engine and not just
its core.

The user supplies an array, where each entry holds the engine's ID and
the command to send to the engine. The size of the array is limited
by the number of engines in the ASIC (only Gaudi2 is currently
supported).

Signed-off-by: Koby Elbaz <kelbaz@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

accel/habanalabs: fix few misspelled words in the code

Run spell checker on the code and fix accordingly.

Signed-off-by: farah kassabri <fkassabri@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

accel/habanalabs: change user interrupt to threaded IRQ

We prefer not to handle the user interrupt job inside the interrupt
context. Instead, use threaded IRQ to handle the user interrupts.
This will allow to avoid disabling interrupts when the user process
registers for a new event and to avoid long handling inside an
interrupt.

Signed-off-by: Tal Cohen <talcohen@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>

accel/habanalabs: add info when FD released while device still in use

When user closes the device file descriptor, it is checked whether the
device is still in use, and a message is printed if it is.
To make this message more informative, add to this print also the reason
due to which the device is considered as in use.
The possible reasons which are checked for now are active CS and
exported dma-buf.

Signed-off-by: Tomer Tayar <ttayar@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>

accel/habanalabs: increase user interrupt grace time

Currently we support scenarios where a timestamp registration request
of a certain offset is received during the interrupt handling of the
same offset. In this case we give a grace period of up to 100us for
the interrupt handler to finish.
It seems that sometimes the interrupt handling takes more than expected,
and therefore this path should be optimized. Until that happens, let's
increase the grace period in order not to reach timeout which will
cause user call to be rejected.

Signed-off-by: Ofir Bitton <obitton@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>

habanalabs: optimize command submission completion timestamp

Completion timestamp is taken during the actual command submission
release. As the release happens in a work queue, the timestamp taken
is not accurate. Hence, we will take the timestamp in the interrupt
handler itself while propagating it to the release function.

Signed-off-by: Ofir Bitton <obitton@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

habanalabs: fix bug in timestamps registration code

Protect re-using the same timestamp buffer record before actually
adding it to the to interrupt wait list.
Mark ts buff offset as in use in the spinlock protection area of the
interrupt wait list to avoid getting in the re-use section in
ts_buff_get_kernel_ts_record before adding the node to the list.
this scenario might happen when multiple threads are racing on
same offset and one thread could set data in the ts buff in
ts_buff_get_kernel_ts_record then the other thread takes over
and get to ts_buff_get_kernel_ts_record and we will try
to re-use the same ts buff offset then we will try to
delete a non existing node from the list.

Signed-off-by: farah kassabri <fkassabri@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

habanalabs: check pad and reserved fields in ioctls

Make sure all reserved/pad fields in uapi input structures
are set to 0.

Signed-off-by: farah kassabri <fkassabri@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

habanalabs: add uapi to flush inbound HBM transactions

When doing p2p with a NIC device, the NIC needs to make sure all the
writes to the HBM (through the PCI bar of the Gaudi device) were
flushed.

It can be done by either the NIC or the host reading through the PCI
bar.

To support the host side, we supply a simple uapi to perform this flush
through the driver, because the user can't create such a transaction
by itself (the PCI bar isn't exposed to normal users).

Signed-off-by: Ohad Sharabi <osharabi@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

habanalabs: move driver to accel subsystem

Now that we have a subsystem for compute accelerators, move the
habanalabs driver to it.

This patch only moves the files and fixes the Makefiles. Future
patches will change the existing code to register to the accel
subsystem and expose the accel device char files instead of the
habanalabs device char files.

Update the MAINTAINERS file to reflect this change.

Signed-off-by: Oded Gabbay <ogabbay@kernel.org>