gpu: host1x: Don't rely on dma_fence_wait_timeout return value

dma_fence_wait_timeout (along with a host of other jiffies-based
timeouting functions) returns zero both in case of timeout and when
the wait completes during the last jiffy before timeout. As such,
we can't rely on it to distinguish between success and timeout.

To prevent confusing callers by returning -EAGAIN before the timeout
period has elapsed, check if the fence got signaled again after
the wait.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: External timeout/cancellation for fences

Currently all fences have a 30 second timeout to ensure they are
cleaned up if the fence never completes otherwise. However, this
one size fits all solution doesn't actually fit in every case,
such as syncpoint waiting where we want to be able to have timeouts
longer than 30 seconds. As such, we want to be able to give control
over fence cancellation to the caller (and maybe eventually get rid
of the internal timeout altogether).

Here we add this cancellation mechanism by essentially adding a
function for entering the timeout path by function call, and changing
the syncpoint wait function to use it.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Implement syncpoint wait using DMA fences

In anticipation of removal of the intr API, move host1x_syncpt_wait
to use DMA fences instead. As of this patch, this means that waits
have a 30 second maximum timeout because of the implicit timeout
we have with fences, but that will be lifted in a follow-up patch.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Always return syncpoint value when waiting

The new TegraDRM UAPI uses syncpoint waiting with timeout set to
zero to indicate reading the syncpoint value. To support that we
need to return the syncpoint value always when waiting.

Fixes: 44e961381354 ("drm/tegra: Implement syncpoint wait UAPI")
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Fix hang on Tegra186+

Tegra186+ hangs if host1x hardware is disabled at a kernel boot time
because we touch hardware before runtime PM is resumed. Move sync point
assignment initialization to the RPM-resume callback. Older SoCs were
unaffected because they skip that sync point initialization.

Tested-by: Jon Hunter <jonathanh@nvidia.com> # T186
Reported-by: Jon Hunter <jonathanh@nvidia.com> # T186
Fixes: 6b6776e2ab8a ("gpu: host1x: Add initial runtime PM and OPP support")
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Add initial runtime PM and OPP support

Add runtime PM and OPP support to the Host1x driver. For the starter we
will keep host1x always-on because dynamic power management require a major
refactoring of the driver code since lot's of code paths are missing the
RPM handling and we're going to remove some of these paths in the future.

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Peter Geis <pgwipeout@gmail.com> # Ouya T30
Tested-by: Paul Fertser <fercerpav@gmail.com> # PAZ00 T20
Tested-by: Nicolas Chauvet <kwizart@gmail.com> # PAZ00 T20 and TK1 T124
Tested-by: Matt Merhar <mattmerhar@protonmail.com> # Ouya T30
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Add no-recovery mode

Add a new property for jobs to enable or disable recovery i.e.
CPU increments of syncpoints to max value on job timeout. This
allows for a more solid model for hanged jobs, where userspace
doesn't need to guess if a syncpoint increment happened because
the job completed, or because job timeout was triggered.

On job timeout, we stop the channel, NOP all future jobs on the
channel using the same syncpoint, mark the syncpoint as locked
and resume the channel from the next job, if any.

The future jobs are NOPed, since because we don't do the CPU
increments, the value of the syncpoint is no longer synchronized,
and any waiters would become confused if a future job incremented
the syncpoint. The syncpoint is marked locked to ensure that any
future jobs cannot increment the syncpoint either, until the
application has recognized the situation and reallocated the
syncpoint.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Reserve VBLANK syncpoints at initialization

On T20-T148 chips, the bootloader can set up a boot splash
screen with DC configured to increment syncpoint 26/27
at VBLANK. Because of this we shouldn't allow these syncpoints
to be allocated until DC has been reset and will no longer
increment them in the background.

As such, on these chips, reserve those two syncpoints at
initialization, and only mark them free once the DC
driver has indicated it's safe to do so.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Reset max value when freeing a syncpoint

With job recovery becoming optional, syncpoints may have a mismatch
between their value and max value when freed. As such, when freeing,
set the max value to the current value of the syncpoint so that it
is in a sane state for the next user.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Cleanup and refcounting for syncpoints

Add reference counting for allocated syncpoints to allow keeping
them allocated while jobs are referencing them. Additionally,
clean up various places using syncpoint IDs to use host1x_syncpt
pointers instead.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Use HW-equivalent syncpoint expiration check

Make syncpoint expiration checks always use the same logic used by
the hardware. This ensures that there are no race conditions that
could occur because of the hardware triggering a syncpoint interrupt
and then the driver disagreeing.

One situation where this could occur is if a job incremented a
syncpoint too many times -- then the hardware would trigger an
interrupt, but the driver would assume that a syncpoint value
greater than the syncpoint's max value is in the future, and not
clean up the job.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Remove cancelled waiters immediately

Before this patch, cancelled waiters would only be cleaned up
once their threshold value was reached. Make host1x_intr_put_ref
process the cancellation immediately to fix this.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Allow syncpoints without associated client

Syncpoints don't need to be associated with any client,
so remove the property, and expose host1x_syncpt_alloc.
This will allow allocating syncpoints without prior knowledge
of the engine that it will be used with.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Rename "parent" to "host"

Rename the host1x clients' parent to "host" because that more closely
describes what it is. The parent can be confused with the parent device
in terms of the device hierarchy. Subsequent patches will add a new
member that refers to the parent in that hierarchy.

Signed-off-by: Thierry Reding <treding@nvidia.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms and conditions of the gnu general public license
version 2 as published by the free software foundation this program
is distributed in the hope it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not see http www gnu org
licenses

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 228 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528171438.107155473@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

gpu: host1x: Drop unnecessary host1x argument

Functions taking a pointer to a host1x syncpoint as an argument don't
need to specify a pointer to a host1x instance because it can be
obtained from the syncpoint.

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Cleanup loop variable usage

Use unsigned int where possible and don't unnecessarily initialize the
loop variable.

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Remove wait check support

The job submission userspace ABI doesn't support this and there are no
plans to implement it, so all of this code is dead and can be removed.

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Enable Tegra186 syncpoint protection

Since Tegra186 the Host1x hardware allows syncpoints to be assigned to
specific channels, preventing any other channels from incrementing
them.

Enable this feature where available and assign syncpoints to channels
when submitting a job. Syncpoints are currently never unassigned from
channels since that would require extra work and is unnecessary with
the current channel allocation model.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: syncpt: Request syncpoints per client

Rather than request syncpoints for a struct device *, request them for a
struct host1x_client *. This is important because subsequent patches are
going to break the assumption that host1x will always be the parent for
devices requesting a syncpoint. It's also a more natural choice because
host1x clients are really the only ones that will know how to deal with
syncpoints.

Note that host1x clients are always guaranteed to be children of host1x,
regardless of their location in the device tree.

Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Flesh out kerneldoc

Improve kerneldoc for the public parts of the host1x infrastructure in
preparation for adding driver-specific part to the GPU documentation.

Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Fix potential out-of-bounds access

The check for valid syncpoint IDs is off by one. While at it, rewrite
the check to make it more easily understandable.

Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Add locking to syncpt

Currently syncpoints are not locked by mutex and this causes races
if we are aggressively freeing and allocating syncpoints.

This patch adds missing mutex protection to syncpoint structures.

Signed-off-by: Arto Merilainen <amerilainen@nvidia.com>
Reviewed-by: Shridhar Rasal <srasal@nvidia.com>
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
[treding@nvidia.com: use better label names, don't reset local variable]
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Remove useless local variable

The local 'val' variable is used to store a value and immediately return
it to its caller, and hence serves no purpose. Just drop it and directly
return the value.

Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Whitespace cleanup for readability

Insert a number of blank lines in places where they increase readability
of the code. Also collapse various variable declarations to shorten some
functions and finally rewrite some code for readability.

Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Fix a couple of checkpatch warnings

Fix a couple of occurrences where no blank line was used to separate
variable declarations from code or where block comments were wrongly
formatted.

Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: syncpt: Use kcalloc() instead of kzalloc()

Use kcalloc() to allocate arrays rather than passing the product of the
size per element by the number of elements to kzalloc().

Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Use unsigned int consistently for IDs

IDs can never be negative so use unsigned int. In some instances an
explicitly sized type (such as u32) was used for no particular reason,
so turn those into unsigned int as well for consistency.

Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Consistently use unsigned int for counts

The number of channels, syncpoints, bases and mlocks can never be
negative, so use unsigned int instead of int. Also make loop variables
the same type for consistency.

Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Export host1x_syncpt_read()

This function is used to read the current value of the syncpt and is
useful in situations where drivers don't schedule work and wait for the
syncpoint to increment. One particular use-case is using the syncpoint
as a VBLANK counter.

Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: export host1x_syncpt_incr_max() function

Tegra V4L2 camera driver needs this function to do frame capture.

Signed-off-by: Bryan Wu <pengw@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Export public API

Make the public API symbols visible so that depending drivers can be
built as a module.

Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Add syncpoint base support

This patch adds support for hardware syncpoint bases. This creates
a simple mechanism to stall the command FIFO until an operation is
completed.

Signed-off-by: Arto Merilainen <amerilainen@nvidia.com>
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Add 'flags' field to syncpt request

Functions host1x_syncpt_request() and _host1x_syncpt_alloc() have
been taking a separate boolean flag ('client_managed') for indicating
if the syncpoint value should be tracked by the host1x driver.

This patch converts the field into generic 'flags' field so that
we can easily add more information while requesting a syncpoint.
Clients are adapted to use the new interface accordingly.

Signed-off-by: Arto Merilainen <amerilainen@nvidia.com>
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Expose syncpt and channel functionality

Expose the buffer objects, syncpoint and channel functionality in the
public public header so that drivers can use them.

Signed-off-by: Thierry Reding <treding@nvidia.com>

gpu: host1x: Rework CPU syncpoint increment

This patch merges host1x_syncpt_cpu_incr to host1x_syncpt_incr() as
they are in practise doing the same thing. host1x_syncpt_incr() is
also modified to return error codes. User space interface is modified
accordingly to pass return values.

Signed-off-by: Arto Merilainen <amerilainen@nvidia.com>
Acked-By: Terje Bergstrom <tbergstrom@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

gpu: host1x: Fix client_managed type

client_managed field in syncpoint structure was defined as an
integer. The field holds, however, only a boolean value. This patch
modifies the type to boolean.

Signed-off-by: Arto Merilainen <amerilainen@nvidia.com>
Acked-By: Terje Bergstrom <tbergstrom@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

gpu: host1x: Fix memory access in syncpt request

This patch fixes a bad memory access in syncpoint request code. If
no syncpoints were available, the code accessed unreserved memory
area causing unexpected behaviour.

Signed-off-by: Arto Merilainen <amerilainen@nvidia.com>
Acked-By: Terje Bergstrom <tbergstrom@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

gpu: host1x: Add debug support

Add support for host1x debugging. Adds debugfs entries, and dumps
channel state to UART in case of stuck job.

Signed-off-by: Arto Merilainen <amerilainen@nvidia.com>
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de>
Tested-by: Thierry Reding <thierry.reding@avionic-design.de>
Tested-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>

gpu: host1x: Add channel support

Add support for host1x client modules, and host1x channels to submit
work to the clients.

Signed-off-by: Arto Merilainen <amerilainen@nvidia.com>
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de>
Tested-by: Thierry Reding <thierry.reding@avionic-design.de>
Tested-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>

gpu: host1x: Add syncpoint wait and interrupts

Add support for sync point interrupts, and sync point wait. Sync
point wait used interrupts for unblocking wait.

Signed-off-by: Arto Merilainen <amerilainen@nvidia.com>
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de>
Tested-by: Thierry Reding <thierry.reding@avionic-design.de>
Tested-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>

gpu: host1x: Add host1x driver

Add host1x, the driver for host1x and its client unit 2D. The Tegra
host1x module is the DMA engine for register access to Tegra's
graphics- and multimedia-related modules. The modules served by
host1x are referred to as clients. host1x includes some other
functionality, such as synchronization.

Signed-off-by: Arto Merilainen <amerilainen@nvidia.com>
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de>
Tested-by: Thierry Reding <thierry.reding@avionic-design.de>
Tested-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>