When GuC submission is enabled, the GuC controls engine resets. Rather
than explicitly triggering a reset, the driver must submit a hanging
context to GuC and wait for the reset to occur.

Conversely, one of the tests specifically sends hanging batches to the
engines but wants them to sit around until a manual reset of the full
GT (including GuC itself). That means disabling GuC based engine
resets to prevent those from killing the hanging batch too soon. So,
add support to the scheduling policy helper for disabling resets as
well as making them quicker!

In GuC submission mode, the 'is engine idle' test basically turns into
'is engine PM wakelock held'. Independently, there is a heartbeat
disable helper function that the tests use. For unexplained reasons,
this acquires the engine wakelock before disabling the heartbeat and
only releases it when re-enabling the heartbeat. As one of the tests
tries to do a wait for idle in the middle of a heartbeat disabled
section, it is therefore guaranteed to always fail. Added a 'no_pm'
variant of the heartbeat helper that allows the engine to be asleep
while also having heartbeats disabled.
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Signed-off-by: NMatthew Brost <matthew.brost@intel.com>
Reviewed-by: NMatthew Brost <matthew.brost@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210727002348.97202-31-matthew.brost@intel.com

There are many ways in which the hangcheck selftest can fail. Very few
of them actually printed an error message to say what happened. So,
fill in the missing messages.
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Signed-off-by: NMatthew Brost <matthew.brost@intel.com>
Reviewed-by: NMatthew Brost <matthew.brost@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210727002348.97202-27-matthew.brost@intel.com

This better models where we want to go with contexts in general where
things like the VM and engine set are create parameters instead of being
set after the fact.
Signed-off-by: NJason Ekstrand <jason@jlekstrand.net>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210708154835.528166-28-jason@jlekstrand.net

The submission tasklet operates on i915_sched_engine, thus it is the
correct place for it.

v3:
 (Jason Ekstrand)
  Change sched_engine->engine to a void* private data pointer
  Add kernel doc
v4:
 (Daniele)
  Update private_data comment
  Set queue_priority_hint in kick_execlists
v5:
 (CI)
  Rebase and fix build error
Signed-off-by: NMatthew Brost <matthew.brost@intel.com>
Reviewed-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210618010638.98941-9-matthew.brost@intel.com

The schedule function should be in the schedule object.

v3:
 (Jason Ekstrand)
  Add kernel doc
Signed-off-by: NMatthew Brost <matthew.brost@intel.com>
Reviewed-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210618010638.98941-6-matthew.brost@intel.com

This was done by the following semantic patch:

	@@ expression i915; @@
	- INTEL_GEN(i915)
	+ GRAPHICS_VER(i915)

	@@ expression i915; expression E; @@
	- INTEL_GEN(i915) >= E
	+ GRAPHICS_VER(i915) >= E

	@@ expression dev_priv; expression E; @@
	- !IS_GEN(dev_priv, E)
	+ GRAPHICS_VER(dev_priv) != E

	@@ expression dev_priv; expression E; @@
	- IS_GEN(dev_priv, E)
	+ GRAPHICS_VER(dev_priv) == E

	@@
	expression dev_priv;
	expression from, until;
	@@
	- IS_GEN_RANGE(dev_priv, from, until)
	+ IS_GRAPHICS_VER(dev_priv, from, until)

	@def@
	expression E;
	identifier id =~ "^gen$";
	@@
	- id = GRAPHICS_VER(E)
	+ ver = GRAPHICS_VER(E)

	@@
	identifier def.id;
	@@
	- id
	+ ver

It also takes care of renaming the variable we assign to GRAPHICS_VER()
so to use "ver" rather than "gen".
Signed-off-by: NLucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210605155356.4183026-2-lucas.demarchi@intel.com

Determine the possible coherent map type based on object location,
and if target has llc or if user requires an always coherent
mapping.

Cc: Matthew Auld <matthew.auld@intel.com>
Cc: CQ Tang <cq.tang@intel.com>
Suggested-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: NVenkata Sandeep Dhanalakota <venkata.s.dhanalakota@intel.com>
Signed-off-by: NMatthew Auld <matthew.auld@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210427085417.120246-2-matthew.auld@intel.com

Clean up the SPDX licence declarations to comply with checkpatch.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210122192913.4518-1-chris@chris-wilson.co.ukSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Convert a few calls to use the unlocked versions.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NThomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-53-maarten.lankhorst@linux.intel.com

The engine resets selftests kick the tasklets, safe up until now as only
execlists supported engine resets.
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/20210119110802.22228-2-chris@chris-wilson.co.uk

Inject a fault into the engine reset and check that the outstanding
requests are completed despite the failed reset.
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/20210113205049.22565-1-chris@chris-wilson.co.uk

During igt_reset_nop_engine, an engine reset unexpectedly failed. For the
next time this happens, mention which engine that was.
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/20210111105735.21515-4-chris@chris-wilson.co.uk

Rather than having special case code for opportunistically calling
process_csb() and performing a direct submit while holding the engine
spinlock for submitting the request, simply call the tasklet directly.
This allows us to retain the direct submission path, including the CS
draining to allow fast/immediate submissions, without requiring any
duplicated code paths, and most importantly greatly simplifying the
control flow by removing reentrancy. This will enable us to close a few
races in the virtual engines in the next few patches.

The trickiest part here is to ensure that paired operations (such as
schedule_in/schedule_out) remain under consistent locking domains,
e.g. when pulled outside of the engine->active.lock

v2: Use bh kicking, see commit 3c53776e ("Mark HI and TASKLET
softirq synchronous").
v3: Update engine-reset to be tasklet aware
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/20201224135544.1713-1-chris@chris-wilson.co.uk

A couple of very simple tests to ensure that the basic properties of
per-engine busyness accounting [0% and 100% busy] are faithful.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200617130916.15261-1-chris@chris-wilson.co.uk

Since we temporarily disable the heartbeat and restore back to the
default value, we can use the stored defaults on the engine and avoid
using a local.
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/20200519063123.20673-3-chris@chris-wilson.co.uk
(cherry picked from commit 3a230a55)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

If the engine dies after a reset, and so we fail to submit a request
but need to be interrupted by the CI runner, dump the engine state.
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/20200615165013.22973-2-chris@chris-wilson.co.uk

We have a test case to exercise resetting an engine while the other
engines are busy, all the TEST_SELF adds on top is that the target
engine also has background activity. In this case it is useful to first
test resetting the engine while there is background activity, as a
separate flag from exercising all others.
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/20200607222108.14401-3-chris@chris-wilson.co.uk

In some of our hangtests, we try to reset an active engine while it is
spinning inside the recursive spinner. However, we also try to flood the
engine with requests that preempt the hang, and so should disable the
preemption to be sure that we reset the right request.
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/20200607222108.14401-2-chris@chris-wilson.co.uk

Since we temporarily disable the heartbeat and restore back to the
default value, we can use the stored defaults on the engine and avoid
using a local.
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/20200519063123.20673-3-chris@chris-wilson.co.uk

Trying to use i915_request_skip() prior to i915_request_add() causes us
to try and fill the ring upto request->postfix, which has not yet been
set, and so may cause us to memset() past the end of the ring.

Instead of skipping the request immediately, just flag the error on the
request (only accepting the first fatal error we see) and then clear the
request upon submission.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200304121849.2448028-1-chris@chris-wilson.co.uk

use intel_uc_uses_guc_submission() directly instead, to be consistent in
the way we check what we want to do with the GuC.

v2: do not go through ctx->vm->gt, use i915->gt instead
Signed-off-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com> #v1
Reviewed-by: NAndi Shyti <andi.shyti@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200218223327.11058-3-daniele.ceraolospurio@intel.com

In the near future, we will want to start a GPU error capture from a new
context, from inside the softirq region of a forced preemption. To do
so requires us to break up the monolithic error capture to provide new
entry points with finer control; in particular focusing on one
engine/gt, and being able to compose an error state from little pieces
of HW capture.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Acked-by: NAndi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200110123059.1348712-1-chris@chris-wilson.co.uk

Attempt to split i915_gem_gtt.[ch] into more manageable chunks.
Suggested-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NMatthew Auld <matthew.auld@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
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/20200107134009.3255354-1-chris@chris-wilson.co.uk

Allocate only an internal intel_context for the kernel_context, forgoing
a global GEM context for internal use as we only require a separate
address space (for our own protection).

Now having weaned GT from requiring ce->gem_context, we can stop
referencing it entirely. This also means we no longer have to create random
and unnecessary GEM contexts for internal use.

GEM contexts are now entirely for tracking GEM clients, and intel_context
the execution environment on the GPU.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Acked-by: NAndi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191221160324.1073045-1-chris@chris-wilson.co.uk

Since drm provided us with a real struct file we can use for our
anonymous internal clients (mock_file), complete our transition to using
that as the primary interface (and not the mocked up struct drm_file we
previous were using).
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/20191107213929.23286-1-chris@chris-wilson.co.uk

As drm now exports a method to create an anonymous struct file around a
drm_device for internal use, make use of it to avoid our horrible hacks.

Danial suggested that the mock_file_put() wrapper was suitable for
drm-core, along with the mock_drm_getfile() [and that the vestigal
mock_drm_file() in this patch should perhaps be the drm interface
itself]. However, the eventual goal is to remove the mock_drm_file() and
use the struct file and fput() directly, in this patch we take a simple
transition in that direction.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20191107180601.30815-3-chris@chris-wilson.co.uk

An interesting observation made with our parallel selftests was that on
our small/single cpu systems we would call kthread_stop() before the
kthreads were spawned. If this happens, the kthread is never run at all;
completely bypassing the test.

A simple yield() from the parent will ensure that all children have the
opportunity to start before we reap them.
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/20191101084940.31838-1-chris@chris-wilson.co.uk

We may be missing support for the mappable aperture on some platforms.
Signed-off-by: NMatthew Auld <matthew.auld@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@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/20191029095856.25431-7-matthew.auld@intel.com

As we are inside the gt, we have a local gt->engine[] lookup we should
be using in preference over the i915->engine[] copy.
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/20191027225808.19437-1-chris@chris-wilson.co.uk

When setting up the system to perform the atomic reset, we need to
serialise with any ongoing interrupt tasklet or else:

<0> [472.951428] i915_sel-4442    0d..1 466527056us : __i915_request_submit: rcs0 fence 11659:2, current 0
<0> [472.951554] i915_sel-4442    0d..1 466527059us : __execlists_submission_tasklet: rcs0: queue_priority_hint:-2147483648, submit:yes
<0> [472.951681] i915_sel-4442    0d..1 466527061us : trace_ports: rcs0: submit { 11659:2, 0:0 }
<0> [472.951805] i915_sel-4442    0.... 466527114us : __igt_atomic_reset_engine: i915_reset_engine(rcs0:active) under hardirq
<0> [472.951932] i915_sel-4442    0d... 466527115us : intel_engine_reset: rcs0 flags=11d
<0> [472.952056] i915_sel-4442    0d... 466527117us : execlists_reset_prepare: rcs0: depth<-1
<0> [472.952179] i915_sel-4442    0d... 466527119us : intel_engine_stop_cs: rcs0
<0> [472.952305]   <idle>-0       1..s1 466527119us : process_csb: rcs0 cs-irq head=3, tail=4
<0> [472.952431] i915_sel-4442    0d... 466527122us : __intel_gt_reset: engine_mask=1
<0> [472.952557]   <idle>-0       1..s1 466527124us : process_csb: rcs0 csb[4]: status=0x00000001:0x00000000
<0> [472.952683]   <idle>-0       1..s1 466527130us : trace_ports: rcs0: promote { 11659:2*, 0:0 }
<0> [472.952808] i915_sel-4442    0d... 466527131us : execlists_reset: rcs0
<0> [472.952933] i915_sel-4442    0d..1 466527133us : process_csb: rcs0 cs-irq head=3, tail=4
<0> [472.953059] i915_sel-4442    0d..1 466527134us : process_csb: rcs0 csb[4]: status=0x00000001:0x00000000
<0> [472.953185] i915_sel-4442    0d..1 466527136us : trace_ports: rcs0: preempted { 11659:2*, 0:0 }
<0> [472.953310] i915_sel-4442    0d..1 466527150us : assert_pending_valid: Nothing pending for promotion!
<0> [472.953436] i915_sel-4442    0d..1 466527158us : process_csb: process_csb:1930 GEM_BUG_ON(!assert_pending_valid(execlists, "promote"))

We have the same CSB events being seen by process_csb() on two different
processors. One being issued by the reset in the test, the other by the
interrupt; this scenario is supposed to be prevented by flushing the
interrupt tasklet with tasklet_disable() before we enter the atomic
reset.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=112069Signed-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/20191023232443.17450-1-chris@chris-wilson.co.uk

Replace sampling the engine state every so often with a periodic
heartbeat request to measure the health of an engine. This is coupled
with the forced-preemption to allow long running requests to survive so
long as they do not block other users.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Reviewed-by: NJon Bloomfield <jon.bloomfield@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191023133108.21401-5-chris@chris-wilson.co.uk

Where the function, or code segment, operates on intel_gt, we need to
start passing it instead of i915 to for_each_engine(_masked).

This is another partial step in migration of i915->engines[] to
gt->engines[].
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
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/20191017094500.21831-2-tvrtko.ursulin@linux.intel.com

Avoid going to the base i915 device when we already have a path from gt
to the runtime powermanagement interface. The benefit is that it looks a
bit more self-consistent to always be acquiring the gt->uncore->rpm for
use with the gt->uncore.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191007154531.1750-1-chris@chris-wilson.co.uk

Keep track of the GEM contexts underneath i915->gem.contexts and assign
them their own lock for the purposes of list management.

v2: Focus on lock tracking; ctx->vm is protected by ctx->mutex
v3: Correct split with removal of logical HW ID
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/20191004134015.13204-15-chris@chris-wilson.co.uk

We don't need to hold struct_mutex now for retiring requests, so drop it
from i915_retire_requests() and i915_gem_wait_for_idle(), finally
removing I915_WAIT_LOCKED for good.
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/20191004134015.13204-8-chris@chris-wilson.co.uk

Replace the struct_mutex requirement for pinning the i915_vma with the
local vm->mutex instead. Note that the vm->mutex is tainted by the
shrinker (we require unbinding from inside fs-reclaim) and so we cannot
allocate while holding that mutex. Instead we have to preallocate
workers to do allocate and apply the PTE updates after we have we
reserved their slot in the drm_mm (using fences to order the PTE writes
with the GPU work and with later unbind).

In adding the asynchronous vma binding, one subtle requirement is to
avoid coupling the binding fence into the backing object->resv. That is
the asynchronous binding only applies to the vma timeline itself and not
to the pages as that is a more global timeline (the binding of one vma
does not need to be ordered with another vma, nor does the implicit GEM
fencing depend on a vma, only on writes to the backing store). Keeping
the vma binding distinct from the backing store timelines is verified by
a number of async gem_exec_fence and gem_exec_schedule tests. The way we
do this is quite simple, we keep the fence for the vma binding separate
and only wait on it as required, and never add it to the obj->resv
itself.

Another consequence in reducing the locking around the vma is the
destruction of the vma is no longer globally serialised by struct_mutex.
A natural solution would be to add a kref to i915_vma, but that requires
decoupling the reference cycles, possibly by introducing a new
i915_mm_pages object that is own by both obj->mm and vma->pages.
However, we have not taken that route due to the overshadowing lmem/ttm
discussions, and instead play a series of complicated games with
trylocks to (hopefully) ensure that only one destruction path is called!

v2: Add some commentary, and some helpers to reduce patch churn.
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/20191004134015.13204-4-chris@chris-wilson.co.uk

As we execute GPU resets on a gt/ basis, and use the intel_gt as the
primary for all other reset functions, also use it for the has-reset?
predicates. Gradually simplifying the churn of pointers.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Reviewed-by: NAndi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190927211749.2181-1-chris@chris-wilson.co.uk

We can reduce the locking for fence registers from the dev->struct_mutex
to a local mutex. We could introduce a mutex for the sole purpose of
tracking the fence acquisition, except there is a little bit of overlap
with the fault tracking, so use the i915_ggtt.mutex as it covers both.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190822060914.2671-1-chris@chris-wilson.co.uk

Make sure that when submitting requests, we always serialize against
potential vma moves and clflushes.

Time for a i915_request_await_vma() interface!
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/20190819112033.30638-1-chris@chris-wilson.co.uk

Smatch spotted that we test at the start of hang_fini for a valid (h->gt
is only set after a request is created) but then used it regardless
later on.

v2: Alternatively, we do not need to check as we now always prime h->gt
in hang_init()

References: cb823ed9 ("drm/i915/gt: Use intel_gt as the primary object for handling resets")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190729085944.2179-1-chris@chris-wilson.co.uk