It is wrong to block the user thread in the next poll when OA data is
already available which could not fit in the user buffer provided in
the previous read. In several cases the exact user buffer size is not
known. Blocking user space in poll can lead to data loss when the
buffer size used is smaller than the available data.

This change fixes this issue and allows user space to read all OA data
even when using a buffer size smaller than the available data using
multiple non-blocking reads rather than staying blocked in poll till
the next timer interrupt.

v2: Fix ret value for blocking reads (Umesh)
v3: Mistake during patch send (Ashutosh)
v4: Remove -EAGAIN from comment (Umesh)
v5: Improve condition for clearing pollin and return (Lionel)
v6: Improve blocking read loop and other cleanups (Lionel)
v7: Added Cc stable

Testcase: igt/perf/polling-small-buf
Reviewed-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Signed-off-by: NAshutosh Dixit <ashutosh.dixit@intel.com>
Cc: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200403010120.3067-1-ashutosh.dixit@intel.com

Make sure we revoke the user's mmaps of this vma to force them to take a
pagefault *before* we remove the associated aperture detiling register.

Fixes: 0d86ee35 ("drm/i915/gt: Make fence revocation unequivocal")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200403160951.8271-1-chris@chris-wilson.co.uk

Move the final DP_TP_CTL frobbing of port sync to the master
encoder's enable hook. Now neatly out of sight from the high level
modeset code.

And thus we've eliminated all the special casing of port sync
in the high level modeset code.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200313164831.5980-14-ville.syrjala@linux.intel.comReviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>

We're going to want access to the atomic state for iterating
the slave crtcs when enabling the port sync master crtc. Pass
the atomic state all the way down.

The alternative would be yet another encoder hook which we'll
have to call after all the normal modeset stuff is done. Not
really a fan of yet another hook just for this.

Note that during readout state sanitation we are now going
to pass NULL as the atomic state since we don't have one.
We need to change that and then we can also s/crtc_state/crtc/
and s/conn_state/conn/ for the encoder hooks as well.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200313164831.5980-13-ville.syrjala@linux.intel.comReviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>

Currently only port sync pipes do the sequence such that
we first do the modeset part for every pipe and then do
the plane/etc. updates. Let's follow that apporach for
all pipes in skl+ so that we can properly integrate the
port sync into the normal modeset flow.

v2: Remove now stale TODO of port sync slave entries[]
    s/oldnew/new/
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200313164831.5980-12-ville.syrjala@linux.intel.comReviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>

Don't assume there is just one port sync slave. We might have several.

v2: Fix unitialized new_crtc_state usage (José)
    Fix clearing of modeset_pipes for slaves
    s/oldnew/new/
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200313164831.5980-11-ville.syrjala@linux.intel.comReviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>

Remove the copy pasted port sync crtc enable functions and instead
just split the normal function into the two parts we need.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200313164831.5980-10-ville.syrjala@linux.intel.comReviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>

Transcoder port sync was introduced to the hardware in BDW. We
can trivially enable it for SKL+ since the same codepaths are
already used for ICL+ port sync. The only difference is the actual
location of the bits we need to poke.

We leave BDW out (at least for now) since it uses different modeset
paths that haven't been adapted for port sync, and IIRC using the
feature would involve some extra workarounds we've not implemented.

Pre-BDW hardware does not support port sync so we'd have to tweak
the modeset sequence to start the pipes as close together as possible
and hope for the best. So far no one has seriously tried to implement
that.

Closes: https://gitlab.freedesktop.org/drm/intel/issues/27Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200313164831.5980-9-ville.syrjala@linux.intel.comReviewed-by: NManasi Navare <manasi.d.navare@intel.com>

We have a bunch of code that would like to know which
CPU transcoders are actually present in the hardware. Rather than
use various ad-hoc methods let's just include a full bitmask in
the device info, alongside pipe_mask.

v2: Rebase
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200318170235.15176-1-ville.syrjala@linux.intel.comReviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>

We use timer->expires == 0 to detect if a timer had been cancelled, but
it's a valid expiration we could set. Just skip using 0 and set the
expiry for the next jiffie.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200403073657.13427-1-chris@chris-wilson.co.uk

Add a tiny per-engine request mempool so that we should always have a
request available for powermanagement allocations from tricky
contexts. This reserve is expected to be only used for kernel
contexts when barriers must be emitted [almost] without fail.

The main consumer for this reserved request is expected to be engine-pm,
for which we know that there will always be at least the previous pm
request that we can reuse under mempressure (so there should always be
a spare request for engine_park()).

This is an alternative to using a comparatively bulky mempool, which
requires custom handling for both our reserved allocation requirement
and to protect our TYPESAFE_BY_RCU slab cache. The advantage of mempool
would be that it would allow us to keep a larger per-engine request
pool. However, converting over to mempool is straightforward should the
need arise.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-and-tested-by: NJanusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200402184037.21630-1-chris@chris-wilson.co.uk

This workaround now applies to all steppings, not just A0.
Wa_1409085225 is a temporary A0-only W/A however it is
identical to Wa_14010229206 and hence the combined workaround
is made permanent.
Bspec: 52890
Signed-off-by: NSwathi Dhanavanthri <swathi.dhanavanthri@intel.com>
Tested-by: NRafael Antognolli <rafael.antognolli@intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
[mattrope: added missing blank line]
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200326234955.16155-1-swathi.dhanavanthri@intel.com

In order to kill off a hostile context, we need to be able to reset the
GPU. So check that is supported prior to beginning the test.
Reported-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200402205839.25065-1-chris@chris-wilson.co.uk

Now that we can peek at GEM->engines[] and obtain a reference to them
using RCU, do so for instances where we can safely iterate the
potentially old copy of the engines. For setting, we can do this when we
know the engine properties are copied over before swapping, so we know
the new engines already have the global property and we update the old
before they are discarded. For reading, we only need to be safe; as we
do so on behalf of the user, their races are their own problem.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200402124218.6375-1-chris@chris-wilson.co.uk

If we receive the error interrupt before the CS interrupt, we may find
ourselves without an active request to reset, skipping the GPU reset.
All because the attempt to reset was too early.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200401110435.30389-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c:205: warning: Excess function parameter 'supported' description in 'intel_uc_fw_init_early'
drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c:205: warning: Excess function parameter 'platform' description in 'intel_uc_fw_init_early'
drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c:205: warning: Excess function parameter 'rev' description in 'intel_uc_fw_init_early'

drivers/gpu/drm/i915/gt/uc/intel_guc_log.c:696: warning: Function parameter or member 'log' not described in 'intel_guc_log_info'
drivers/gpu/drm/i915/gt/uc/intel_guc_log.c:696: warning: Excess function parameter 'guc' description in 'intel_guc_log_info'
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200330212254.18236-1-chris@chris-wilson.co.uk

We cached the number of vma bound to the object in order to speed up
shrinker decisions. This has been superseded by being more proactive in
removing objects we cannot shrink from the shrinker lists, and so we can
drop the clumsy attempt at atomically counting the bind count and
comparing it to the number of pinned mappings of the object. This will
only get more clumsier with asynchronous binding and unbinding.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200401223924.16667-1-chris@chris-wilson.co.uk

If we must revoke the fence because the VMA is no longer present, or
because the fence no longer applies, ensure that we do and convert it
into an error if we try but cannot.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200401210104.15907-3-chris@chris-wilson.co.uk

Make a copy of the object tiling parameters at the point of grabbing the
fence.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200401210104.15907-2-chris@chris-wilson.co.uk

Only GPU activity via the GGTT fence is asynchronous, we know that we
control the CPU access directly, so we only need to wait for the GPU to
stop using the fence before we relinquish it.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200401210104.15907-1-chris@chris-wilson.co.uk

If the current node/entry location is occupied, and the object is not
pinned, try assigning it some free space. We cannot wait here, so if in
doubt, we unreserve and try to grab all at once.

v2: Use the final pin_flags so that we won't have to move the object if
we find the wrong free space.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200401194135.5442-1-chris@chris-wilson.co.uk

There is a spelling mistake in comment, fix it.
Signed-off-by: NChen Zhou <chenzhou10@huawei.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200401022506.52965-1-chenzhou10@huawei.com

Insert a space so that the same fields between active/pending execlists
state are aligned.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200401111554.6279-1-chris@chris-wilson.co.uk

If the user passes in a readonly reloc[], by the time we notice we have
already committed to modifying the execobjects, or have indeed done so
already. Reporting the failure just compounds the issue as we have no
second pass to fall back to anymore.

"Be damned if you do, and damned if you don't."

Testcase: igt/gem_exec_reloc/readonly
Fixes: 7dc8f114 ("drm/i915/gem: Drop relocation slowpath")
References: fddcd00a ("drm/i915: Force the slow path after a user-write error")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NAndi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200331162150.3635-1-chris@chris-wilson.co.uk

When we allocate space in the GGTT we may have to allocate a larger
region than will be populated by the object to accommodate fencing. Make
sure that this space beyond the end of the buffer points safely into
scratch space, in case the HW tries to access it anyway (e.g. fenced
access to the last tile row).

v2: Preemptively / conservatively guard gen6 ggtt as well.
Reported-by: NImre Deak <imre.deak@intel.com>
References: https://gitlab.freedesktop.org/drm/intel/-/issues/1554Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200331152348.26946-1-chris@chris-wilson.co.uk

For CI it is enough to point out a single failure
in isolation. However it is beneficial to gather
info in logs for transients further down
the line.

Do not stop into first comparison failure but
continue probing forward.

v2: for all engines and poisons (Chris)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200331135403.16906-1-mika.kuoppala@linux.intel.com

Since we print out EXECLISTS_STATUS in the dump, also print out the CCID
of each context so we can cross check between the two.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200331094239.23145-1-chris@chris-wilson.co.uk

Since we may be attempting to reset an active engine, we try to freeze
it in place before resetting -- to be on the safe side. We can go one
step further if we are using the CS flow semaphore to prevent the
context switching into the next.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200331091459.29179-2-chris@chris-wilson.co.uk

Since we don't wait for the error interrupt to reset, restart and then
complete the guilty request, clean up the error messages.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200331091459.29179-1-chris@chris-wilson.co.uk

Add a few telltales to see when timeslicing is being enabled.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200331120502.14713-1-chris@chris-wilson.co.uk

Since we may kick more than engine, and may kick each one a couple of
times, coalesce the tasklet execution to the end. This also ensures that
we have the chance to run the tasklet immediately after priority
bumping.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200331114852.11583-1-chris@chris-wilson.co.uk

Specification was updated with vswing tables for different
configurations.
Also reordering icl_mg_phy_ddi_buf_trans struct to match table order.

BSpec: 21735
Signed-off-by: NJosé Roberto de Souza <jose.souza@intel.com>
Reviewed-by: NClinton Taylor <clinton.a.taylor@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200330210044.130510-3-jose.souza@intel.com

EHL has now only one table for all DP rates.

BSpec: 21257
Signed-off-by: NJosé Roberto de Souza <jose.souza@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200330210044.130510-2-jose.souza@intel.com

DDI ports have its encoders initialized with INTEL_OUTPUT_DDI type and
later eDP ports that have the type changed to INTEL_OUTPUT_EDP.
But for all other DDI ports it can drive HDMI or DP depending on what
user connects to the ports.

ehl_get_combo_buf_trans() and tgl_get_combo_buf_trans() was checking
for INTEL_OUTPUT_DP that was never true, causing wrong vswing tables
being used.

So here replacing the INTEL_OUTPUT_DP checks by the valid output types
that this functions receives as parameters. HDMI cases will be
correctly handled as it do not use encoder->type, instead it calls the
functions with INTEL_OUTPUT_HDMI as type parameter and HDMI don't have
retraining.

v2:
changed INTEL_OUTPUT_DDI to INTEL_OUTPUT_EDP and INTEL_OUTPUT_HDMI

Fixes: bd3cf6f7 ("drm/i915/dp/tgl+: Update combo phy vswing tables")
Cc: Clinton A Taylor <clinton.a.taylor@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJosé Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200330210044.130510-1-jose.souza@intel.com

The DDI IO power well must not be enabled for a TypeC port in TBT mode,
ensure this during driver loading/system resume.

This gets rid of error messages like
[drm] *ERROR* power well DDI E TC2 IO state mismatch (refcount 1/enabled 0)

and avoids leaking the power ref when disabling the output.

Cc: <stable@vger.kernel.org> # v5.4+
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200330152244.11316-1-imre.deak@intel.com

  process_csb: 0000:00:02.0 bcs0: cs-irq head=4, tail=5
  process_csb: 0000:00:02.0 bcs0: csb[5]: status=0x00008002:0x60000020
  trace_ports: 0000:00:02.0 bcs0: preempted { ff84:45154! prio 2 }
  trace_ports: 0000:00:02.0 bcs0: promote { ff84:45155* prio 2 }
  trace_ports: 0000:00:02.0 bcs0: submit { ff84:45156 prio 2 }

  process_csb: 0000:00:02.0 bcs0: cs-irq head=5, tail=6
  process_csb: 0000:00:02.0 bcs0: csb[6]: status=0x00000018:0x60000020
  trace_ports: 0000:00:02.0 bcs0: completed { ff84:45155* prio 2 }
  process_csb: 0000:00:02.0 bcs0: ring:{start:0x00178000, head:0928, tail:0928, ctl:00000000, mode:00000200}
  process_csb: 0000:00:02.0 bcs0: rq:{start:00178000, head:08b0, tail:08f0, seqno:ff84:45155, hwsp:45156},
  process_csb: 0000:00:02.0 bcs0: ctx:{start:00178000, head:e000928, tail:0928},
  process_csb: GEM_BUG_ON("context completed before request")

In this sequence, we can see that although we have submitted the next
request [ff84:45156] to HW (via ELSP[]) it has not yet reported the
lite-restore. Instead, we see the completion event of the currently
active request [ff84:45155] but at the time of processing that event,
the breadcrumb has not yet been written. Though by the time we do print
out the debug info, the seqno write of ff84:45156 has landed!

Therefore there is a serialisation problem between the seqno writes and
CS events, not just between the CS buffer and its head/tail pointers as
previously observed on Icelake.

This is not a huge problem, as we don't strictly rely on the breadcrumb
to determine HW activity, but it may indicate that interrupt delivery is
before the seqno write, aka bringing back the plague of missed
interrupts from yesteryear. However, there is no indication of this
wider problem, so let's just flush the seqno read before reporting an
error. If it persists after the fresh read we can worry again.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200330234318.30638-1-chris@chris-wilson.co.uk

Reading or writing those fields should only happen under
stream->oa_buffer.ptr_lock.
Signed-off-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Fixes: d1df41eb ("drm/i915/perf: rework aging tail workaround")
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NAshutosh Dixit <ashutosh.dixit@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200330091411.37357-1-lionel.g.landwerlin@intel.com

Upon a GPU reset, we copy the default context image over top of the
guilty image. This will rollback the CTX_TIMESTAMP register to before
our value of ce->runtime.last. Reset both back to 0 so that we do not
encounter an underflow on the next schedule out after resume.

This should not be a huge issue in practice, as hangs should be rare in
correct code.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200330125827.5804-1-chris@chris-wilson.co.uk

Use a separate array allocation for the execbuf vma, so that we can
track their lifetime independently from the copy of the user arguments.
With luck, this has a secondary benefit of splitting the malloc size to
within reason and avoid vmalloc. The downside is that we might require
two separate vmallocs -- but much less likely.

In the process, this prevents a memory leak on the ww_mutex error
unwind.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/1390Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200330133710.14385-1-chris@chris-wilson.co.uk

We wish that the scheduler emit the context modification commands prior
to enabling the oa_config, for which we must explicitly inform it of the
ordering constraints. This is especially important as we now wait for
the final oa_config setup to be completed and as this wait may be on a
distinct context to the state modifications, we need that command packet
to be always last in the queue.

We borrow the i915_active for its ability to track multiple timelines
and the last dma_fence on each; a flexible dma_resv. Keeping track of
each dma_fence is important for us so that we can efficiently schedule
the requests and reprioritise as required.
Reported-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200327112212.16046-3-chris@chris-wilson.co.uk