Hardware engineers confirmed that writing to it has no effect, as implied
by the FIXME comment.

v2: Also remove comment from bxt_ddi_phy_verify_state(). (Imre)
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1478069096-11209-1-git-send-email-ander.conselvan.de.oliveira@intel.com

Commit 1bec9b0b ("drm/i915/shrinker: Only shmemfs objects
are backed by swap") stopped considering the userptr objects
in shrinker callbacks.

Restore that so idle userptr objects can be discarded in order
to free up memory.

One change further to what was introduced in 1bec9b0b is
to start considering userptr objects in oom but that should
also be a correct thing to do.

v2: Introduce I915_GEM_OBJECT_IS_SHRINKABLE. (Chris Wilson)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Fixes: 1bec9b0b ("drm/i915/shrinker: Only shmemfs objects are backed by swap")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: <stable@vger.kernel.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1478011450-6634-1-git-send-email-tvrtko.ursulin@linux.intel.com

Unify our approach to things by passing around dev_priv instead of dev.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-27-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by passing around dev_priv instead of dev.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-26-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by passing around dev_priv instead of dev.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-25-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by passing around dev_priv instead of dev.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-24-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by passing around dev_priv instead of dev.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-23-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by passing around dev_priv instead of dev.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-22-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by passing around dev_priv instead of dev.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-21-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by passing around dev_priv instead of dev.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-20-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by passing around dev_priv instead of dev.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-19-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by passing around dev_priv instead of dev.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-18-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by passing around dev_priv instead of dev.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-17-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by passing around dev_priv instead of dev.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-16-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by passing around dev_priv instead of dev.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-15-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by passing around dev_priv instead of dev.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-14-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by passing around dev_priv instead of dev.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-13-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Replace the open coded dev_priv->pipe_to_crtc_mapping[] usage with
intel_get_crtc_for_pipe().

Mostly done with coccinelle, with a few manual tweaks

@@
expression E1, E2;
@@
(
- E1->pipe_to_crtc_mapping[E2]
+ intel_get_crtc_for_pipe(E1, E2)
|
- E1->plane_to_crtc_mapping[E2]
+ intel_get_crtc_for_plane(E1, E2)
)
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-12-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by passing around dev_priv instead of dev.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-11-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by passing around dev_priv instead of dev.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-10-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by passing around dev_priv instead of dev.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-9-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by passing around dev_priv instead of dev.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-8-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

A lot of users of the {pipe,plane}_to_crtc_mapping[] will end up
casting the result to intel_crtc, so let's just store the intel_crtc
pointer in the first place.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-7-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by using intel_crtc instead of drm_crtc.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-6-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by passing around intel_crtc instead of
drm_crtc.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-5-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by passing around intel_crtc instead of
drm_crtc.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-4-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by passing around dev_priv instead of dev.
While at it let's do some house cleaning: s/intel_foo/foo/ and move
things into tighter scope.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-3-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Unify our approach to things by passing around dev_priv instead of dev.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477946245-14134-2-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

For legacy contexts we employ an optimisation to only flush the context
when binding into the global GTT. This avoids stalling on the GPU when
reloading an active context. Wrap this detail up into a helper and
export it for a potential third user. (Longer term, context pinning
needs to be reworked as the current handling of switch context pins too
late and so risks eviction and corrupting the request. Plans, plans,
plans.)

v2: Expand the comment explaining the optimisation for avoiding the
stall on active contexts.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20161030132820.32163-1-chris@chris-wilson.co.ukReviewed-by: NMatthew Auld <matthew.auld@intel.com>

There's no need to keep a duplicate skl_pipe_wm around any more,
everything can be discovered from crtc_state, which we pass around
correctly now even in case of plane disable.

The copy in intel_crtc->wm.skl.active is equal to
crtc_state->wm.skl.optimal after the atomic commit completes.
It's useful for two-step watermark programming, but not required for
gen9+ which does it in a single step. We can pull the old allocation
from old_crtc_state.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477489299-25777-9-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NMatt Roper <matthew.d.roper@intel.com>

Move calculating minimum allocations to a helper, which cleans up the
code some more. The cursor is still allocated in advance because it
doesn't count towards data rate and should always be reserved.

changes since v1:
- Change comment to have a extra opening line. (Matt)
- Rebase to remove unused plane->pipe == pipe, handled by the iterator
  now. (Paulo)
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477489299-25777-7-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>

This is not required any more now that we get fresh state from
drm_atomic_crtc_state_for_each_plane_state. Zero all state
in advance.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477489299-25777-6-git-send-email-maarten.lankhorst@linux.intel.com

It's only used in one function, and can be calculated without caching it
in the global struct by using drm_atomic_crtc_state_for_each_plane_state.

There are loops over all planes, including planes that don't exist.
This is harmless, because data_rate will always be 0 for them and we
never program them when updating watermarks.

Changes since v1:
- Rename rate back to data_rate, and change array name to
  plane_data_rate. (Matt)
- Remove whitespace. (Paulo)
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477489299-25777-5-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>

Using for_each_intel_plane_on_crtc will allow us to find all allocations
that may have changed, not just the one added by the atomic state.

This will print changes to plane allocations for crtc's when some
planes are not added to the atomic state.

Changes since v1:
- Rephrase commit message. (Ville)
- Use plane->base.id and plane->name to kill off cursor special
  case. (Ville)
- Add intel_crtc to prevent a line wrap. (Paulo)
- Line wrap debug messages.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/c9f7dc1a-d23a-7c16-b2b7-1c23dd07ed35@linux.intel.comReviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>

I'm planning on getting rid of all obj->state dereferences,
and replace thhem with accessor functions.
Remove this one early, they're equivalent because removed
planes are already part of the state, else they could not
have been removed.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477489299-25777-3-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NMatt Roper <matthew.d.roper@intel.com>

Caching is not required, drm_atomic_crtc_state_for_each_plane_state can
be used to inspect the states of all planes assigned to the CRTC even
if they are not part of _state, so we can just recalculate every time.

Changes since v1:
- Remove plane->pipe checks, they're implied by the macros.
- Split unrelated changes to a separate commit.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477489299-25777-2-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>

The shrinker may appear to recurse into obj->mm.lock as the shrinker may
be called from a direct reclaim path whilst handling get_pages. We
filter out recursing on the same obj->mm.lock by inspecting
obj->mm.pages, but we do want to take the lock on a second object in
order to reap their pages. lockdep spots the recursion on the same
lockclass and needs annotation to avoid a false positive. To keep the
two paths distinct, create an enum to indicate which subclass of
obj->mm.lock we are using. This removes the false positive and avoids
masking real bugs.
Suggested-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161101121134.27504-1-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

With full-ppgtt one of the main bottlenecks is the lookup of the VMA
underneath the object. For execbuf there is merit in having a very fast
direct lookup of ctx:handle to the vma using a hashtree, but that still
leaves a large number of other lookups. One way to speed up the lookup
would be to use a rhashtable, but that requires extra allocations and
may exhibit poor worse case behaviour. An alternative is to use an
embedded rbtree, i.e. no extra allocations and deterministic behaviour,
but at the slight cost of O(lgN) lookups (instead of O(1) for
rhashtable). The major of such tree will be very shallow and so not much
slower, and still scales much, much better than the current unsorted
list.

v2: Bump vma_compare() to return a long, as we return the result of
comparing two pointers.

References: https://bugs.freedesktop.org/show_bug.cgi?id=87726Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161101115400.15647-1-chris@chris-wilson.co.uk

If we have a tiled object and an unknown CPU swizzle pattern, we pin the
pages to prevent the object from being swapped out (and us corrupting
the contents as we do not know the access pattern and so cannot convert
it to linear and back to tiled on reuse). This requires us to remember
to drop the extra pinning when freeing the object, or else we trigger
warnings about the pin leak. In commit fbbd37b3 ("drm/i915: Move
object release to a freelist + worker"), the object free path was
deferred to a worker, but the unpinning of the quirk, along with marking
the object as reclaimable, was left on the immediate path (so that if
required we could reclaim the pages under memory pressure as early as
possible). However, this split introduced a bug where the pages were no
longer being unpinned if they were marked as unneeded.

[  231.800401] WARNING: CPU: 1 PID: 90 at drivers/gpu/drm/i915/i915_gem.c:4275 __i915_gem_free_objects+0x326/0x3c0 [i915]
[  231.800403] WARN_ON(i915_gem_object_has_pinned_pages(obj))
[  231.800405] Modules linked in:
[  231.800406]  snd_hda_intel i915 snd_hda_codec_generic mei_me snd_hda_codec coretemp snd_hwdep mei lpc_ich snd_hda_core snd_pcm e1000e ptp pps_core [last unloaded: i915]
[  231.800426] CPU: 1 PID: 90 Comm: kworker/1:4 Tainted: G     U          4.9.0-rc2-CI-CI_DRM_1780+ #1
[  231.800428] Hardware name: LENOVO 7465CTO/7465CTO, BIOS 6DET44WW (2.08 ) 04/22/2009
[  231.800456] Workqueue: events __i915_gem_free_work [i915]
[  231.800459]  ffffc9000034fc80 ffffffff8142dd65 ffffc9000034fcd0 0000000000000000
[  231.800465]  ffffc9000034fcc0 ffffffff8107e4e6 000010b300000001 0000000000001000
[  231.800469]  ffff88011d3db740 ffff880130ef0000 0000000000000000 ffff880130ef5ea0
[  231.800474] Call Trace:
[  231.800479]  [<ffffffff8142dd65>] dump_stack+0x67/0x92
[  231.800484]  [<ffffffff8107e4e6>] __warn+0xc6/0xe0
[  231.800487]  [<ffffffff8107e54a>] warn_slowpath_fmt+0x4a/0x50
[  231.800491]  [<ffffffff811d12ac>] ? kmem_cache_free+0x2dc/0x340
[  231.800520]  [<ffffffffa009ef36>] __i915_gem_free_objects+0x326/0x3c0 [i915]
[  231.800548]  [<ffffffffa009effe>] __i915_gem_free_work+0x2e/0x50 [i915]
[  231.800552]  [<ffffffff8109c27c>] process_one_work+0x1ec/0x6b0
[  231.800555]  [<ffffffff8109c1f6>] ? process_one_work+0x166/0x6b0
[  231.800558]  [<ffffffff8109c789>] worker_thread+0x49/0x490
[  231.800561]  [<ffffffff8109c740>] ? process_one_work+0x6b0/0x6b0
[  231.800563]  [<ffffffff8109c740>] ? process_one_work+0x6b0/0x6b0
[  231.800566]  [<ffffffff810a2aab>] kthread+0xeb/0x110
[  231.800569]  [<ffffffff810a29c0>] ? kthread_park+0x60/0x60
[  231.800573]  [<ffffffff818164a7>] ret_from_fork+0x27/0x40

Moving to a separate flag for tracking the quirked pin is overkill for
the bug (since we only have to interchange the two tests in
i915_gem_free_object) but it does reduce a complicated test on all
objects and provide a sanitycheck for uncommon code paths.

Fixes: fbbd37b3 ("drm/i915: Move object release to a freelist + worker")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161101100317.11129-2-chris@chris-wilson.co.uk

Whilst waiting on a request, we may do so without holding any locks or
any guards beyond a reference to the request. In order to avoid taking
locks within request deallocation, we drop references to its timeline
(via the context and ppgtt) upon retirement. We should avoid chasing
such pointers outside of their control, in particular we inspect the
request->timeline to see if we may restore the RPS waitboost for a
client. If we instead look at the engine->timeline, we will have similar
behaviour on both full-ppgtt and !full-ppgtt systems and reduce the
amount of reward we give towards stalling clients (i.e. only if the
client stalls and the GPU is uncontended does it reclaim its boost).
This restores behaviour back to pre-timelines, whilst fixing:

[  645.078485] BUG: KASAN: use-after-free in i915_gem_object_wait_fence+0x1ee/0x2e0 at addr ffff8802335643a0
[  645.078577] Read of size 4 by task gem_exec_schedu/28408
[  645.078638] CPU: 1 PID: 28408 Comm: gem_exec_schedu Not tainted 4.9.0-rc2+ #64
[  645.078724] Hardware name:                  /        , BIOS PYBSWCEL.86A.0027.2015.0507.1758 05/07/2015
[  645.078816]  ffff88022daef9a0 ffffffff8143d059 ffff880235402a80 ffff880233564200
[  645.078998]  ffff88022daef9c8 ffffffff81229c5c ffff88022daefa48 ffff880233564200
[  645.079172]  ffff880235402a80 ffff88022daefa38 ffffffff81229ef0 000000008110a796
[  645.079345] Call Trace:
[  645.079404]  [<ffffffff8143d059>] dump_stack+0x68/0x9f
[  645.079467]  [<ffffffff81229c5c>] kasan_object_err+0x1c/0x70
[  645.079534]  [<ffffffff81229ef0>] kasan_report_error+0x1f0/0x4b0
[  645.079601]  [<ffffffff8122a244>] kasan_report+0x34/0x40
[  645.079676]  [<ffffffff81634f5e>] ? i915_gem_object_wait_fence+0x1ee/0x2e0
[  645.079741]  [<ffffffff81229951>] __asan_load4+0x61/0x80
[  645.079807]  [<ffffffff81634f5e>] i915_gem_object_wait_fence+0x1ee/0x2e0
[  645.079876]  [<ffffffff816364bf>] i915_gem_object_wait+0x19f/0x590
[  645.079944]  [<ffffffff81636320>] ? i915_gem_object_wait_priority+0x500/0x500
[  645.080016]  [<ffffffff8110fb30>] ? debug_show_all_locks+0x1e0/0x1e0
[  645.080084]  [<ffffffff8110abdc>] ? check_chain_key+0x14c/0x210
[  645.080157]  [<ffffffff8110a796>] ? __lock_is_held+0x46/0xc0
[  645.080226]  [<ffffffff8163bc61>] ? i915_gem_set_domain_ioctl+0x141/0x690
[  645.080296]  [<ffffffff8163bcc2>] i915_gem_set_domain_ioctl+0x1a2/0x690
[  645.080366]  [<ffffffff811f8f85>] ? __might_fault+0x75/0xe0
[  645.080433]  [<ffffffff815a55f7>] drm_ioctl+0x327/0x640
[  645.080508]  [<ffffffff8163bb20>] ? i915_gem_obj_prepare_shmem_write+0x3a0/0x3a0
[  645.080603]  [<ffffffff815a52d0>] ? drm_ioctl_permit+0x120/0x120
[  645.080670]  [<ffffffff8110abdc>] ? check_chain_key+0x14c/0x210
[  645.080738]  [<ffffffff81275717>] do_vfs_ioctl+0x127/0xa20
[  645.080804]  [<ffffffff8120268c>] ? do_mmap+0x47c/0x580
[  645.080871]  [<ffffffff811da567>] ? vm_mmap_pgoff+0x117/0x140
[  645.080938]  [<ffffffff812755f0>] ? ioctl_preallocate+0x150/0x150
[  645.081011]  [<ffffffff81108c53>] ? up_write+0x23/0x50
[  645.081078]  [<ffffffff811da567>] ? vm_mmap_pgoff+0x117/0x140
[  645.081145]  [<ffffffff811da450>] ? vma_is_stack_for_current+0x90/0x90
[  645.081214]  [<ffffffff8110d853>] ? mark_held_locks+0x23/0xc0
[  645.082030]  [<ffffffff81288408>] ? __fget+0x168/0x250
[  645.082106]  [<ffffffff819ad517>] ? entry_SYSCALL_64_fastpath+0x5/0xb1
[  645.082176]  [<ffffffff81288592>] ? __fget_light+0xa2/0xc0
[  645.082242]  [<ffffffff8127604c>] SyS_ioctl+0x3c/0x70
[  645.082309]  [<ffffffff819ad52e>] entry_SYSCALL_64_fastpath+0x1c/0xb1
[  645.082374] Object at ffff880233564200, in cache kmalloc-8192 size: 8192
[  645.082431] Allocated:
[  645.082480] PID = 28408
[  645.082535]  [  645.082566] [<ffffffff8103ae66>] save_stack_trace+0x16/0x20
[  645.082623]  [  645.082656] [<ffffffff81228b06>] save_stack+0x46/0xd0
[  645.082716]  [  645.082756] [<ffffffff812292fd>] kasan_kmalloc+0xad/0xe0
[  645.082817]  [  645.082848] [<ffffffff81631752>] i915_ppgtt_create+0x52/0x220
[  645.082908]  [  645.082941] [<ffffffff8161db96>] i915_gem_create_context+0x396/0x560
[  645.083027]  [  645.083059] [<ffffffff8161f857>] i915_gem_context_create_ioctl+0x97/0xf0
[  645.083152]  [  645.083183] [<ffffffff815a55f7>] drm_ioctl+0x327/0x640
[  645.083243]  [  645.083274] [<ffffffff81275717>] do_vfs_ioctl+0x127/0xa20
[  645.083334]  [  645.083372] [<ffffffff8127604c>] SyS_ioctl+0x3c/0x70
[  645.083432]  [  645.083464] [<ffffffff819ad52e>] entry_SYSCALL_64_fastpath+0x1c/0xb1
[  645.083551] Freed:
[  645.083599] PID = 27629
[  645.083648]  [  645.083676] [<ffffffff8103ae66>] save_stack_trace+0x16/0x20
[  645.083738]  [  645.083770] [<ffffffff81228b06>] save_stack+0x46/0xd0
[  645.083830]  [  645.083862] [<ffffffff81229203>] kasan_slab_free+0x73/0xc0
[  645.083922]  [  645.083961] [<ffffffff812279c9>] kfree+0xa9/0x170
[  645.084021]  [  645.084053] [<ffffffff81629f60>] i915_ppgtt_release+0x100/0x180
[  645.084139]  [  645.084171] [<ffffffff8161d414>] i915_gem_context_free+0x1b4/0x230
[  645.084257]  [  645.084288] [<ffffffff816537b2>] intel_lr_context_unpin+0x192/0x230
[  645.084380]  [  645.084413] [<ffffffff81645250>] i915_gem_request_retire+0x620/0x630
[  645.084500]  [  645.085226] [<ffffffff816473d1>] i915_gem_retire_requests+0x181/0x280
[  645.085313]  [  645.085352] [<ffffffff816352ba>] i915_gem_retire_work_handler+0xca/0xe0
[  645.085440]  [  645.085471] [<ffffffff810c725b>] process_one_work+0x4fb/0x920
[  645.085532]  [  645.085562] [<ffffffff810c770d>] worker_thread+0x8d/0x840
[  645.085622]  [  645.085653] [<ffffffff810d21e5>] kthread+0x185/0x1b0
[  645.085718]  [  645.085750] [<ffffffff819ad7a7>] ret_from_fork+0x27/0x40
[  645.085811] Memory state around the buggy address:
[  645.085869]  ffff880233564280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  645.085956]  ffff880233564300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  645.086053] >ffff880233564380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  645.086138]                                ^
[  645.086193]  ffff880233564400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  645.086283]  ffff880233564480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

v2: Add a comment to document the hint like nature of
 intel_engine_last_submit()

Fixes: 73cb9701 ("drm/i915: Combine seqno + tracking into a global timeline struct")
Fixes: 80b204bc ("drm/i915: Enable multiple timelines")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161101100317.11129-1-chris@chris-wilson.co.uk