drivers/gpu/drm/i915/i915_drv.c:891: warning: No description found for parameter 'ent'
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180208105449.29880-1-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

The comment is very old and quite misleading now.

drivers/gpu/drm/i915/i915_gem_context.c:349: warning: No description found for parameter 'dev_priv'
drivers/gpu/drm/i915/i915_gem_context.c:349: warning: No description found for parameter 'file_priv'
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180208111559.32663-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_gem_request.c:941: warning: No description found for parameter 'write'
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180208111453.32567-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_gem_userptr.c:761: warning: No description found for parameter 'dev'
drivers/gpu/drm/i915/i915_gem_userptr.c:761: warning: No description found for parameter 'data'
drivers/gpu/drm/i915/i915_gem_userptr.c:761: warning: No description found for parameter 'file'
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180208111328.32422-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/intel_ringbuffer.c:179: warning: No description found for parameter 'req'
drivers/gpu/drm/i915/intel_ringbuffer.c:741: warning: No description found for parameter 'req'
drivers/gpu/drm/i915/intel_ringbuffer.c:741: warning: No description found for parameter 'cs'
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180208111220.32293-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_gpu_error.c:1815: warning: No description found for parameter 'dev_priv'
drivers/gpu/drm/i915/i915_gpu_error.c:1815: warning: No description found for parameter 'engine_mask'
drivers/gpu/drm/i915/i915_gpu_error.c:1815: warning: No description found for parameter 'error_msg'
drivers/gpu/drm/i915/i915_gpu_error.c:1815: warning: Excess function parameter 'dev' description in 'i915_capture_error_state'
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180208111105.32149-1-chris@chris-wilson.co.uk

After we assert the reset request (and wait for 20us), when the device
has been fully reset it asserts the reset-status bit. Before we stop
requesting the reset and allow the device to return to normal, we should
wait for the reset to be completed. (Similar to how we wait for the
device to return to normal after deasserting the reset request.)

v2: Rename i915_reset_completed() probe to not cause as much confusion.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180207222824.29864-1-chris@chris-wilson.co.ukReviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>

Although the mmio are uncached and so should be flushed on every write,
be paranoid and do a mmio read after setting the ring head/tail to be
sure they have taken effect before moving on.

v2: post tail to be pleasing to the eye
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180208072800.595-1-chris@chris-wilson.co.ukReviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>

Reduce the window of opportunity for set-wedged being called
concurrently with reset (after i915_reset() has performed the
i915_gem_unset_wedged()) by moving the set_bit(I915_WEDGED) to before we
complete the inflight requests. When i915_reset() is being blocked on a
request, such completion may allow it to start and beginning resetting
the GPU before i915_gem_set_wedged() has finished (and so before
set-wedge will have marked the device as wedged). As such,
i915_gem_init_hw() may see a wedged device even from inside
i915_reset().

References: 36703e79 ("drm/i915: Break modeset deadlocks on reset")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180207151350.20883-1-chris@chris-wilson.co.uk

Userspace provides a 64b value for the priority, we need to be careful
to preserve the full range before validation to prevent truncation (and
letting an illegal value pass).
Reported-by: NAntonio Argenziano <antonio.argenziano@intel.com>
Fixes: ac14fbd4 ("drm/i915/scheduler: Support user-defined priorities")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Antonio Argenziano <antonio.argenziano@intel.com>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180208085151.11480-1-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

We only need to wake up the RPS worker once when initially enabling the
client boost, it remains in effect then until the last client no longer
requires the boost.

References: https://bugs.freedesktop.org/show_bug.cgi?id=102250
References: 7b92c1bd ("drm/i915: Avoid keeping waitboost active for signaling threads")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Reviewed-by: NMichał Winiarski <michal.winiarski@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180206143137.15509-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_oa_cnl.c: In function ‘i915_perf_load_test_config_cnl’:
drivers/gpu/drm/i915/i915_oa_cnl.c:99:2: error: ‘strncpy’ output truncated before terminating nul copying 36 bytes from a string of the same length [-Werror=stringop-truncation]

v2: strlcpy

Fixes: 95690a02 ("drm/i915/perf: enable perf support on CNL")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180208102403.5587-2-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_oa_cflgt3.c: In function ‘i915_perf_load_test_config_cflgt3’:
drivers/gpu/drm/i915/i915_oa_cflgt3.c:87:2: error: ‘strncpy’ output truncated before terminating nul copying 36 bytes from a string of the same length [-Werror=stringop-truncation]

v2: strlcpy

Fixes: 4407eaa9 ("drm/i915/perf: add support for Coffeelake GT3")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180208102403.5587-1-chris@chris-wilson.co.uk

Since commit 5896a5c8 (drm/i915: Always stop the rings before a
missing GPU reset) we attempt to stop the engines during gem_sanitize
even if reset=0 and nothing bad happened on the gpu.
The specs says that the STOP_RINGS bit needs to be cleared to resume
normal operation, but for some reason the value of the bit seems to be
changing without us writing to it (maybe rc6 entry/exit?), so normal
operation resumes correctly. However, it still feels incorrect to stop
the engines if there hasn't been any issue so skip the whole reset
call in gem_sanitize if i915.reset=0

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180207212440.13438-1-daniele.ceraolospurio@intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

If we remove some hardcoded assumptions about the preempt context having
a fixed id, reserved from use by normal user contexts, we may only
allocate the i915_gem_context when required. Then the subsequent
decisions on using preemption reduce to having the preempt context
available.

v2: Include an assert that we don't allocate the preempt context twice.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Acked-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180207210544.26351-3-chris@chris-wilson.co.ukReviewed-by: NMichel Thierry <michel.thierry@intel.com>

Rather than having the high level ioctl interface guess the underlying
implementation details, having the implementation declare what
capabilities it exports. We define an intel_driver_caps, similar to the
intel_device_info, which instead of trying to describe the HW gives
details on what the driver itself supports. This is then populated by
the engine backend for the new scheduler capability field for use
elsewhere.

v2: Use caps.scheduler for validating CONTEXT_PARAM_SET_PRIORITY (Mika)
    One less assumption of engine[RCS] \o/
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tomasz Lis <tomasz.lis@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NTomasz Lis <tomasz.lis@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180207210544.26351-2-chris@chris-wilson.co.ukReviewed-by: NMichel Thierry <michel.thierry@intel.com>

In the next patch, we may only conditionally allocate the preempt-client
if there is a global preempt context and so we need to be prepared in
case the preempt-client itself is NULL.

v2: Grep for more preempt_client.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180207210544.26351-1-chris@chris-wilson.co.ukReviewed-by: NMichel Thierry <michel.thierry@intel.com>

As we peek inside struct device to query members guarded by CONFIG_PM,
so must be the code.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Fixes: 1fe699e3 ("drm/i915/pmu: Fix sleep under atomic in RC6 readout")
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/20180207160428.17015-1-chris@chris-wilson.co.uk

We are not allowed to call intel_runtime_pm_get from the PMU counter read
callback since the former can sleep, and the latter is running under IRQ
context.

To workaround this, we record the last known RC6 and while runtime
suspended estimate its increase by querying the runtime PM core
timestamps.

Downside of this approach is that we can temporarily lose a chunk of RC6
time, from the last PMU read-out to runtime suspend entry, but that will
eventually catch up, once device comes back online and in the presence of
PMU queries.

Also, we have to be careful not to overshoot the RC6 estimate, so once
resumed after a period of approximation, we only update the counter once
it catches up. With the observation that RC6 is increasing while the
device is suspended, this should not pose a problem and can only cause
slight inaccuracies due clock base differences.

v2: Simplify by estimating on top of PM core counters. (Imre)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104943
Fixes: 6060b6ae ("drm/i915/pmu: Add RC6 residency metrics")
Testcase: igt/perf_pmu/rc6-runtime-pm
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: David Airlie <airlied@linux.ie>
Cc: intel-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180206183311.17924-1-tvrtko.ursulin@linux.intel.com

On blb and pnv, we are seeing sporadic

  i915 0000:00:02.0: Resetting chip after gpu hang
  [drm:intel_gpu_reset [i915]] rcs0: timed out on STOP_RING
  [drm:i915_reset [i915]] *ERROR* Failed hw init on reset -5

which notably lack the actual root cause of the error. Ostensibly it
should be the init_ring_common() that failed, but it's error paths are
covered by DRM_ERROR.
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/20180207111545.17078-1-chris@chris-wilson.co.uk

If we submit a request and see that the previous request on this
timeline was already signaled, we first do not need to add the
dependency tracker for that completed request and secondly we know that
we there is then a large backlog in retiring requests affecting this
timeline. Given that we just submitted more work to the HW, now would be
a good time to catch up on those retirements.

v2: Try to sum up the compromises involved in flushing the retirement
queue after submission.
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>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180207084350.3929-1-chris@chris-wilson.co.uk

If the last request on the timeline is already complete, we do not need
to emit the serialisation barriers.
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>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180207084350.3929-2-chris@chris-wilson.co.uk

According to bspec, result_lines > 31 is only a maximum for latency
level 1 through 7.

For level 0 the number of lines is ignored, so always write 0 there
to prevent overflowing the 5 bits value.

This is required to make NV12 work.

Changes since v1:
- Rebase on top of GEN11 wm changes. It seems to use res_lines for
  level 0 limit calculations, but still doesn't appear to program it.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> #v1
Link: https://patchwork.freedesktop.org/patch/msgid/20180205105841.31634-1-maarten.lankhorst@linux.intel.com

When a request is preempted, it is unsubmitted from the HW queue and
removed from the active list of breadcrumbs. In the process, this
however triggers the signaler and it may see the clear rbtree with the
old, and still valid, seqno, or it may match the cleared seqno with the
now zero rq->global_seqno. This confuses the signaler into action and
signaling the fence.

Fixes: d6a2289d ("drm/i915: Remove the preempted request from the execution queue")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: <stable@vger.kernel.org> # v4.12+
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180206094633.30181-1-chris@chris-wilson.co.uk

Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

Commit 99e48bf9 ("drm/i915: Lock out execlist tasklet while peeking
inside for busy-stats") added a tasklet_disable call in busy stats
enabling, but we failed to understand that the PMU enable callback runs
as an hard IRQ (IPI).

Consequence of this is that the PMU enable callback can interrupt the
execlists tasklet, and will then deadlock when it calls
intel_engine_stats_enable->tasklet_disable.

To fix this, I realized it is possible to move the engine stats enablement
and disablement to PMU event init and destroy hooks. This allows for much
simpler implementation since those hooks run in normal context (can
sleep).

v2: Extract engine_event_destroy. (Chris Wilson)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Fixes: 99e48bf9 ("drm/i915: Lock out execlist tasklet while peeking inside for busy-stats")
Testcase: igt/perf_pmu/enable-race-*
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: intel-gfx@lists.freedesktop.org
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180205093448.13877-1-tvrtko.ursulin@linux.intel.com

This workaround should prevent a bug that can be hit on a context
restore. To avoid the issue, we must emit a PIPE_CONTROL with CS stall
(0x7a000004 0x00100000 0x00000000 0x00000000) followed by 12DW's of
NOOP(0x0) in the indirect context batch buffer, to ensure the engine is
idle prior to programming 3DSTATE_SAMPLE_PATTERN.

It's also not clear whether we should add those extra dwords because of
the workaround itself, or if that's just padding for the WA BB (and next
commands could come right after the PIPE_CONTROL). We keep them for now.

References: HSD#1939868

 v2: More descriptive changelog and comments.
 v3: Explain that PIPE_CONTROL is actually 6 dwords, and that we advance
     10 more dwords because of that.
Signed-off-by: NRafael Antognolli <rafael.antognolli@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Acked-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/20180205233330.14973-1-rafael.antognolli@intel.com

The command MEDIA_VFE_STATE checks bits at offset +2 dwords. However, it is
possible to have MEDIA_VFE_STATE command with length = 0 + LENGTH_BIAS = 2.
In that case check_cmd will read bits from the following command, or even past
the end of the buffer.

If the offset ends up outside of the command length, reject the command.

Fixes: 351e3db2 ("drm/i915: Implement command buffer parsing logic")
Signed-off-by: NMichal Srb <msrb@suse.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180205151745.29292-1-msrb@suse.comReviewed-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/20180205160438.3267-2-chris@chris-wilson.co.uk

The find_reg function was assuming that there is always at least one table in
reg_tables. It is not always true.

In case of VCS or VECS, the reg_tables is NULL and reg_table_count is 0,
implying that no register-accessing commands are allowed. However, the command
tables include commands such as MI_STORE_REGISTER_MEM. When trying to check
such command, the find_reg would dereference NULL pointer.

Now it will just return NULL meaning that the register was not found and the
command will be rejected.

Fixes: 76ff480e ("drm/i915/cmdparser: Use binary search for faster register lookup")
Signed-off-by: NMichal Srb <msrb@suse.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180205142916.27092-2-msrb@suse.com
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@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/20180205160438.3267-1-chris@chris-wilson.co.uk
register lookup")

Deprecate the silly I915_SET_COLORKEY_NONE flag. The obvious
way to disable colorkey is to just set flags to 0, which is
exactly what the intel ddx has been doing all along.

Currently when userspace sets the flags to 0, we end up in a
funny state where colorkey is disabled, but various colorkey
vs. scaling checks still consider colorkey to be enabled, and
thus we don't allow plane scaling to kick in.

In case there is some other userspace out there that actually
uses this flag (unlikely as this is an i915 specific uapi)
we'll keep on accepting it.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180202204231.27905-1-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Since commit 7b6da818 ("drm/i915: Restore the kernel context after a
GPU reset on an idle engine") we submit a request following the engine
reset. The intent is that we don't submit a request if the engine is
busy (as it will restart active by itself) but we only checked to see if
there were remaining requests in flight on the hardware and skipped
checking to see if there were any ready requests that would be
immediately submitted on restart (the same time as our new request would
be). Having convinced the engine to appear idle in the previous patch,
we can use intel_engine_is_idle() as a better test to only submit a new
request if there are no pending requests.

As it happens, this is tripping up igt/drv_selftest/live_hangcheck in CI
as we overfill the kernel_context ringbuffer trigger an infinite
recursion from within the reset.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104786
References: 7b6da818 ("drm/i915: Restore the kernel context after a GPU reset on an idle engine")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180205152431.12163-4-chris@chris-wilson.co.uk

In preparation for the next patch, we want the engine to appear idle
after a reset (if there are no requests in flight). For execlists, this
entails clearing the active status on reset, it will be regenerated on
restarting the engine after the reset. In the process, note that a
couple of other status flags and checks could be moved into the
describing function.
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/20180205152431.12163-3-chris@chris-wilson.co.uk

Avoid injecting hangs in to the i915->kernel_context in case the GPU
reset leaves corruption in the context image in its wake (leading to
continual failures and system hangs after the selftests are ostensibly
complete). Use a sacrificial kernel_context instead.

v2: Closing a context is tricky; export a function (for selftests) from
i915_gem_context.c to get it right.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180205152431.12163-2-chris@chris-wilson.co.uk

When injecting rapid resets, we must be careful to at least wait for the
previous reset to have taken effect and the engine restarted. If we
perform a second reset before that has happened, we will notice that the
engine hasn't recovered and declare it lost, wedging the device and
failing. In practice, since we wait for each hanging batch to start
before injecting the reset, this too-fast-reset condition can only be
triggered when moving onto the next engine in the test, so we need only
wait for the existing reset to complete before switching engines.

v2: Wrap up the wait inside a safety net to bail out in case of angry hw.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180205152431.12163-1-chris@chris-wilson.co.uk

If we remember to cancel the signaler on a request when retiring it
(after we know that the request has been signaled), we do not need to
carry an additional request in the signaler itself. This prevents an
issue whereby the signaler threads may be delayed and hold on to
thousands of request references, causing severe memory fragmentation and
premature oom (most noticeable on 32b snb due to the limited GFP_KERNEL
and frequent use of inter-engine fences).

v2: Rename first_signal(), document reads outside of locks.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180203101914.24880-1-chris@chris-wilson.co.ukReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

During testing, we trigger a lot of resets on an unbannable context
leading to massive amounts of irrelevant debug spam. Remove the
ban_score accounting and message for the unbannable context so that we
improve the signal:noise in the log messages for when the unexpected
occurs.
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/20180205092201.19476-7-chris@chris-wilson.co.uk

Execlists is now enabled by default and included in the list of
capabilities printed out to dmesg and beyond. We do not need to mention
it again, every time we restart the engine, so kill the spam.
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/20180205092201.19476-6-chris@chris-wilson.co.uk

Dump each engine state when i915_gem_set_wedged() is called to give us
some more clues as to why we had to terminate the GPU.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180205092201.19476-5-chris@chris-wilson.co.uk

Provide the reason why we call intel_fbc_deactivate() so that debugging
issues with FBC being delayed is clearer.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180125224122.27480-1-chris@chris-wilson.co.ukReviewed-by: NJani Nikula <jani.nikula@intel.com>

The headers should be on a separate line for consistency, so add the
missing trailing newline in a few intel_engine_dump() callers.
Reported-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
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/20180205100618.11001-1-chris@chris-wilson.co.uk