Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>

Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>

Whenever we want to unbind a vma, we must wait on all GPU activity to
complete first. (This is what gives us the ability to do fine grained
eviction and purging by only having to wait on the VMA that we need to
unbind to proceed; though if pushed we can make it a rule that we are
only allowed to unbind already idle VMA and move the burden of the work
and organising the sleep onto the caller.) Currently, we might only
sleep if the vma is still active on the GPU, but in principle
i915_vma_unbind() always implies a sleep, so mark it up with a
might_sleep().
Suggested-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
References: https://bugs.freedesktop.org/show_bug.cgi?id=103638Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171109213450.13875-2-chris@chris-wilson.co.uk

vm_free_page() may call down into set_pages_array_wb() (which itself
sleeps, on x86 at least) but only if on !llc and the caches overflow.
Since this is unlikely, we only rarely trigger the error in practice,
and so to make CI detection of this sleeping bug possible we want to
mark the common vm_free_page() as a potential sleep.
Suggested-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
References: https://bugs.freedesktop.org/show_bug.cgi?id=103638Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20171109213450.13875-1-chris@chris-wilson.co.uk

Trying to enable printk debugging for GEM is fraught with the issue of
spam; interactions with HW are very frequent and often boring. However,
one instance where they are not so boring is just before a BUG; here
ftrace provides a facility to dump its ringbuffer on an oops. So for CI
let's enable trace_printk() to capture the last exchanges with HW as a
death rattle.

For example,
[   79.234110] ------------[ cut here ]------------
[   79.234137] kernel BUG at drivers/gpu/drm/i915/intel_lrc.c:907!
[   79.234145] invalid opcode: 0000 [#1] SMP
[   79.234153] Dumping ftrace buffer:
[   79.234158] ---------------------------------
...
[   79.314044] gem_conc-1059    1..s1 79203443us : intel_lrc_irq_handler: bcs0 out[0]: ctx=5.2, seqno=145
[   79.314089] gem_conc-1059    1..s. 79220800us : intel_lrc_irq_handler: bcs0 csb[1/1]: status=0x00000018:0x00000005
[   79.314133] gem_conc-1059    1..s. 79220803us : intel_lrc_irq_handler: bcs0 out[0]: ctx=5.1, seqno=145
[   79.314177] gem_conc-1062    2..s1 79230458us : intel_lrc_irq_handler: bcs0 in[0]:  ctx=8.1, seqno=146
[   79.314220] gem_conc-1062    2..s1 79230515us : intel_lrc_irq_handler: bcs0 in[0]:  ctx=8.2, seqno=147
[   79.314265] gem_conc-1059    1..s1 79230951us : intel_lrc_irq_handler: bcs0 csb[2/3]: status=0x00000012:0x00000008
[   79.314309] gem_conc-1059    1..s1 79230954us : intel_lrc_irq_handler: bcs0 out[0]: ctx=8.2, seqno=147
[   79.314353] gem_conc-1059    1..s1 79230954us : intel_lrc_irq_handler: bcs0 csb[3/3]: status=0x00008002:0x00000008
[   79.314396] gem_conc-1059    1..s1 79230955us : intel_lrc_irq_handler: bcs0 out[0]: ctx=8.1, seqno=147
[   79.314402] ---------------------------------

v2: Tweak the formatting to be more consistent between in/out.
v3: do {} while (0) stub macro protection
Suggested-by: NMichał Winiarski <michal.winiarski@intel.com>
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>
Link: https://patchwork.freedesktop.org/patch/msgid/20171109143019.16568-1-chris@chris-wilson.co.uk

Eliminate a ton of pointless 'dev' variables in the DP code, and pass
around 'dev_priv' instead of 'dev'.

v2: Rebase
Acked-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NDhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171109152758.32257-1-ville.syrjala@linux.intel.com

No need to pass 'dev' or 'dev_priv' when the function already takes
'intel_dp'. Also let's prefer passing 'dev_priv' instead of 'dev'
when we have to pass one or the other.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171031205123.13123-10-ville.syrjala@linux.intel.comAcked-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NDhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>

Remove intel_digital_port->port and replace its users with
intel_encoder->port. intel_encoder->port is a superset of
intel_digital_port->port, and it works correctly even for
MST encoders.

v2: Eliminate a few dp_to_dig_port()->base.port cases too (DK)

Performed with cocci:
@@
@@
struct intel_digital_port {
       ...
-       enum port port;
       ...
}

@@
struct intel_digital_port *D;
expression E;
@@
- D->port = E;

@@
struct intel_digital_port *D;
@@
- D->port
+ D->base.port

@
expression E;
@@
(
- dp_to_dig_port(E)->port
+ dp_to_dig_port(E)->base.port
|
- enc_to_dig_port(E)->port
+ to_intel_encoder(E)->port
)

@@
expression E;
@@
- to_intel_encoder(&E->base)
+ E

@@
struct intel_digital_port *D;
identifier I, M;
@@
  I = &D->base
<...
(
- D->base.M
+ I->M
|
- &D->base
+ I
)
...>

@@
identifier D;
expression E;
identifier M;
@@
 D = enc_to_dig_port(&E->base)
<...
(
- D->base.M
+ E->M
|
- &D->base
+ E
)
...>

@@
identifier D, DP;
expression E;
identifier M;
@@
 DP = enc_to_intel_dp(&E->base)
<...
(
- dp_to_dig_port(DP)->base.M
+ E->M
|
- &dp_to_dig_port(DP)->base
+ E
)
...>

@@
expression E;
identifier M;
@@
(
- enc_to_dig_port(&E->base)->base.M
+ E->M
|
- enc_to_dig_port(&E->base)->base
+ E
|
- enc_to_mst(&E->base)->primary->base.port
+ E->port
)

@@
expression E;
identifier D;
@@
- struct intel_digital_port *D = E;
... when != D

Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: NDhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Acked-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171109152434.32074-1-ville.syrjala@linux.intel.com

Replace dig_port->port with encoder->port in the BXT DPLL selection.
We can do this because both the master encoder and the fake MST encoders
have the same encoder->port value, whereas using dig_port->port only
worked for the master encoder since the fake encoders were't derived
from intel_digital_port. This eliminates the DP MST special case.

Do this by hand because spatch is having problems with the control
flow due to the dig_port assignment happening in two different
branches.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171031205123.13123-8-ville.syrjala@linux.intel.comAcked-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NDhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>

Replace crtc->config usage with the passed down crtc state.

Also take the opportunity for some s/pipe_config/crtc_state/ while at it.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171031205123.13123-7-ville.syrjala@linux.intel.comAcked-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NDhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>

Rather than digging through encoder->crtc and crtc->config in the
DPIO PHY functions, pass down the correct crtc state from the caller.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171031205123.13123-6-ville.syrjala@linux.intel.comAcked-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NDhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>

Extract the current crtc from the crtc state rather than via
the legacy encoder->crtc pointer whenever possible.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171031205123.13123-5-ville.syrjala@linux.intel.comAcked-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NDhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>

Extract the current crtc from the crtc state rather than via
the legacy encoder->crtc pointer whenever possible.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171031205123.13123-4-ville.syrjala@linux.intel.comAcked-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NDhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>

Extract the current crtc from the crtc state rather than via
the legacy encoder->crtc pointer whenever possible.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171031205123.13123-3-ville.syrjala@linux.intel.comAcked-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NDhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>

Extract the current crtc from the crtc state rather than via
the legacy encoder->crtc pointer whenever possible.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171031205123.13123-2-ville.syrjala@linux.intel.comAcked-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NDhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>

When we close the VMA, we unbind it from the ppgtt and tear down the
page directory pointing at it. That may trigger us to return WC pages
back to the system, requiring conversion back to WB which itself may
sleep. That makes i915_vma_close() unsuitable for use inside the RCU
read lock, which we need to hold to iterate the radixtree.

The fix is quite simple, we can close all the VMA as we close the ppgtt,
we only need to do that instead of closing them during destruction of
the LUT.

v2: Order between closing the LUT and the ppgtt is important; we use the
vma inside the LUT as a means of retrieving the object, and so we must
clear the LUT before freeing the VMA when closing the ppgtt.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103638
Fixes: 547da76b ("drm/i915: Hold rcu_read_lock when iterating over the radixtree (vma idr)")
Fixes: d1b48c1e ("drm/i915: Replace execbuf vma ht with an idr")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171109085540.32264-1-chris@chris-wilson.co.ukReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

We can program GUC_SHIM_CONTROL register with all expected
bits without use of extra macro defined in fwif.h

v2: rebased without pre-prod code
v3: fixed typo
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Reviewed-by: NSagar Arun Kamble <sagar.a.kamble@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171103151816.62048-4-michal.wajdeczko@intel.comSigned-off-by: NChris Wilson <chris@chris-wilson.co.uk>

We don't keep the workarounds for pre-production hardware
(see intel_detect_preproduction_hw) thus we can drop some
extra steps during firmware upload needed only for unsupported
platforms.
Suggested-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Reviewed-by: NSagar Arun Kamble <sagar.a.kamble@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171103151816.62048-3-michal.wajdeczko@intel.comSigned-off-by: NChris Wilson <chris@chris-wilson.co.uk>

We silently assumed that DMA transfer will be completed
within assumed timeout and thus we were waiting only at
last step for GuC to become ready. Add intermediate wait
to catch unexpected delays in DMA transfer.
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Reviewed-by: NSagar Arun Kamble <sagar.a.kamble@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171103151816.62048-2-michal.wajdeczko@intel.comSigned-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Transfer of GuC firmware requires few steps that currently
are implemented in two large functions. Split this code into
smaller functions to make these steps small and clear.
Also be prepared for potential DMA xfer step failure.

v2: rename function steps (Sagar)
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Reviewed-by: NSagar Arun Kamble <sagar.a.kamble@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171103151816.62048-1-michal.wajdeczko@intel.comSigned-off-by: NChris Wilson <chris@chris-wilson.co.uk>

The workaround for this is described as:

"if RenderSurfaceState.Num_Multisamples > 1, disable RCC clock gating if
RenderSurfaceState.Num_Multisamples == 1, set 0x7010[14] = 1"

Further documentation in the internal bug referenced by the bspec
suggest that any of the above suggestions should suffice to fix the
issue. We are going with disabling RCC clock gating.

Unfortunately, what we are doing doesn't match the name of the
workaround, but at least it matches its description.

This change improves CNL stability by avoiding some of the hangs seen in
the platform.

v2: Only disable RCC clock gating.
Signed-off-by: NRafael Antognolli <rafael.antognolli@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171103183027.5051-1-rafael.antognolli@intel.com

Apparently setting up a bunch of GT registers before we've properly
initialized the rest of the GT hardware leads to these setting being
lost. So looks like I broke HSW with commit b7048ea1 ("drm/i915:
Do .init_clock_gating() earlier to avoid it clobbering watermarks")
by doing init_clock_gating() too early. This should actually affect
other platforms as well, but apparently not to such a great degree.

What I was ultimately after in that commit was to move the
ilk_init_lp_watermarks() call earlier. So let's undo the damage and
move init_clock_gating() back to where it was, and call
ilk_init_lp_watermarks() just before the watermark state readout.

This highlights how fragile and messed up our init order really is.
I wonder why we even initialize the display before gem. The opposite
order would make much more sense to me...

v2: Keep WaRsPkgCStateDisplayPMReq:hsw early as it really must
    be done before all planes might get disabled.

Cc: stable@vger.kernel.org
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mark Janes <mark.a.janes@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reported-by: NMark Janes <mark.a.janes@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103549
Fixes: b7048ea1 ("drm/i915: Do .init_clock_gating() earlier to avoid it clobbering watermarks")
References: https://lists.freedesktop.org/archives/intel-gfx/2017-November/145432.htmlSigned-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171108133555.14091-1-ville.syrjala@linux.intel.comTested-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

The shared fence array is not autopruning and may continue to grow as an
object is shared between new timelines. Take the opportunity when we
think the object is idle (we have to confirm that any external fence is
also signaled) to decouple all the fences.

We apply a similar trick after waiting on an object, see commit
e54ca977 ("drm/i915: Remove completed fences after a wait")

v2: No longer need to handle the batch pool as a special case.
v3: Need to trylock from within i915_vma_retire as this may be called
form the shrinker - and we may later try to allocate underneath the
reservation lock, so a deadlock is possible.

References: https://bugs.freedesktop.org/show_bug.cgi?id=102936
Fixes: d07f0e59 ("drm/i915: Move GEM activity tracking into a common struct reservation_object")
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>
Link: https://patchwork.freedesktop.org/patch/msgid/20171107220656.5020-1-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

The handling of contexts are peculiar. Instead of tieing their vma to
activity, we pin the context. This means that we cannot simply unbind
the context object itself at will (which would normally cause us to wait
for the vma to be idle), but must manually idle the GPU and retire
requests first.

A consequence of this peculiarity is when doing a last desperate attempt
to recover memory. If the memory is tied up inside active context
objects, we will fail to recover any memory simply by trying to unbind
the objects without first doing a wait-for-idle.

A side-effect of removing the call to shrinker_lock_uninterruptible()
from i915_gem_shrinker_oom() was that we removed an unlocked
wait-for-idle, and so lost the "natural" shrinkage of context objects.
By replacing that with a locked wait from inside i915_gem_shrink(), we
not only replace it with the ability to recover all context objects, but
do so for all i915_gem_shrink_all() callers.

v2: Switching requires request allocation, which is not permitted from
inside the shrinker as it only uses ordinary allocations.

References: https://bugs.freedesktop.org/show_bug.cgi?id=102936
Fixes: f2123818 ("drm/i915: Move dev_priv->mm.[un]bound_list to its own lock")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171108094400.1386-1-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

Upon parking, if we discover an active engine we dump its state. Follow
that state with an indication of whether the engine was idle.

References: https://bugs.freedesktop.org/show_bug.cgi?id=103479Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171107152211.19930-1-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

During intel_atomic_check(), we do not take the intel_runtime_pm_get()
wakeref and so should do the atomic modeset precalculations without
referring to the HW. However, on Ironlake we see

<7>[   23.487557] [drm:intel_atomic_check [i915]] [CONNECTOR:47:VGA-1] checking for sink bpp constrains
<7>[   23.487615] [drm:intel_atomic_check [i915]] clamping display bpp (was 36) to default limit of 24
<4>[   23.487621] RPM wakelock ref not held during HW access
<4>[   23.487652] ------------[ cut here ]------------
<4>[   23.487697] WARNING: CPU: 0 PID: 1343 at drivers/gpu/drm/i915/intel_drv.h:1813 gen5_read32+0x183/0x200 [i915]
<4>[   23.487701] Modules linked in: snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic i915 intel_powerclamp coretemp crct10dif_pclmul crc32_pclmul snd_hda_intel ghash_clmulni_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm lpc_ich e1000e mei_me ptp mei pps_core prime_numbers
<4>[   23.487784] CPU: 0 PID: 1343 Comm: debugfs_test Tainted: G        W       4.14.0-rc7-CI-Trybot_1378+ #1
<4>[   23.487788] Hardware name: Hewlett-Packard HP Compaq 8100 Elite SFF PC/304Ah, BIOS 786H1 v01.13 07/14/2011
<4>[   23.487793] task: ffff8801f90aa6c0 task.stack: ffffc900013ec000
<4>[   23.487838] RIP: 0010:gen5_read32+0x183/0x200 [i915]
<4>[   23.487842] RSP: 0018:ffffc900013efb58 EFLAGS: 00010292
<4>[   23.487849] RAX: 000000000000002a RBX: ffff880205c00000 RCX: 0000000000000006
<4>[   23.487854] RDX: 000000000000140a RSI: ffffffff81d0eb14 RDI: ffffffff81cc26f6
<4>[   23.487857] RBP: ffffc900013efb80 R08: ffff8801f90aaff8 R09: 0000000000000000
<4>[   23.487861] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001
<4>[   23.487865] R13: 0000000000046000 R14: ffff88020ffaba78 R15: ffff88020b109bf8
<4>[   23.487870] FS:  00007f53b5e40a40(0000) GS:ffff88021bc00000(0000) knlGS:0000000000000000
<4>[   23.487874] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4>[   23.487878] CR2: 000055e41900c0e8 CR3: 00000001fa0d6005 CR4: 00000000000206f0
<4>[   23.487882] Call Trace:
<4>[   23.487931]  intel_atomic_check+0x745/0x1290 [i915]
<4>[   23.487948]  drm_atomic_check_only+0x459/0x560
<4>[   23.487956]  ? drm_atomic_set_crtc_for_connector+0xc9/0x100
<4>[   23.488025]  drm_atomic_commit+0x18/0x50
<4>[   23.488035]  restore_fbdev_mode_atomic+0x190/0x1f0
<4>[   23.488059]  restore_fbdev_mode+0x32/0x120
<4>[   23.488072]  drm_fb_helper_restore_fbdev_mode_unlocked+0x50/0xa0
<4>[   23.488139]  intel_fbdev_restore_mode+0x34/0x90 [i915]
<4>[   23.488194]  i915_driver_lastclose+0xe/0x10 [i915]
<4>[   23.488208]  drm_lastclose+0x39/0xf0
<4>[   23.488219]  drm_release+0x30c/0x3c0
<4>[   23.488236]  __fput+0xb9/0x200
<4>[   23.488252]  ____fput+0xe/0x10
<4>[   23.488264]  task_work_run+0x89/0xc0
<4>[   23.488278]  exit_to_usermode_loop+0x83/0x90
<4>[   23.488290]  syscall_return_slowpath+0xd0/0x110
<4>[   23.488304]  entry_SYSCALL_64_fastpath+0xaf/0xb1
<4>[   23.488312] RIP: 0033:0x7f53b4317560
<4>[   23.488320] RSP: 002b:00007ffca7e70748 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
<4>[   23.488333] RAX: 0000000000000000 RBX: 0000000000000001 RCX: 00007f53b4317560
<4>[   23.488340] RDX: 0000000000000005 RSI: 00007ffca7e70640 RDI: 0000000000000004
<4>[   23.488347] RBP: 000055e417783900 R08: 000055e418f9e290 R09: 0000000000000000
<4>[   23.488356] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
<4>[   23.488363] R13: 00007f53b4302c40 R14: 0000000000000000 R15: 0000000000000000
<4>[   23.488384] Code: b5 f2 f2 e0 0f ff e9 c5 fe ff ff 80 3d 0e 4b 10 00 00 0f 85 c6 fe ff ff 48 c7 c7 30 73 29 a0 c6 05 fa 4a 10 00 01 e8 8e f2 f2 e0 <0f> ff e9 ac fe ff ff e8 51 9d f3 e0 85 c0 0f 85 01 ff ff ff 48
<4>[   23.488780] ---[ end trace 6bc72ce7f1596190 ]---
<7>[   23.488844] [drm:intel_atomic_check [i915]] checking fdi config on pipe A, lanes 1
<7>[   23.488911] [drm:intel_atomic_check [i915]] hw max bpp: 36, pipe bpp: 24, dithering: 0

due to intel_fdi_link_freq() poking at FDI_PLL_BIOS_0. Avoid this by
recording the fdi pll frequency during device initiailisation.

v2: Also extract the static FDI PLL frequencies for Sandybridge and
Ivybridge.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171107214713.18704-1-chris@chris-wilson.co.ukReviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

Since the partial tiling tests are poking into the GGTT to watch the
fence registers in operation, it itself needs the device rpm wakeref in
order for the GGTT to remain accessible.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171107115653.10716-1-chris@chris-wilson.co.ukReviewed-by: NMatthew Auld <matthew.auld@intel.com>

The vma routines are responsible for acquiring the device rpm wakeref
before they poke the HW. However, some of the selftests bypass the
higher level vma routines in order to poke directly at the lowlevel GGTT
functions; these are then responsible for managing rpm themselves.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171107114051.10583-1-chris@chris-wilson.co.ukReviewed-by: NMatthew Auld <matthew.auld@intel.com>

If we only have 4k pages, we can't mix together different combinations
of hugepages to see if the world burns. However, as the loops did
nothing, we never set err to 0 and reported ENODEV aborting the test.
Teach the test to skip instead.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171107110559.6098-1-chris@chris-wilson.co.ukReviewed-by: NMatthew Auld <matthew.william.auld@gmail.com>

Smatch warns of

drivers/gpu/drm/i915/intel_pm.c:1161 g4x_compute_wm() warn: signedness bug returning '(-33554430)'

which is a result of it believing that wm may be INT_MAX following
g4x_tlb_miss_wa(). Just declaring g4x_tlb_miss_wa() as returning an
unsigned integer is not sufficient, we need to tell smatch that wm itself
is unsigned for it to not worry. So mark up the locals we expect to be
non-negative, and so silence smatch.

v2: Mark up vlv_compute_wm_level() as unsigned similarly.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> #v1
Link: https://patchwork.freedesktop.org/patch/msgid/20171107140338.13748-1-chris@chris-wilson.co.uk

Older compilers (gcc-4.9) are not as able to track uninitialised
variables as well as more recent compilers. In particular,

drivers/gpu/drm/i915/intel_dpio_phy.c: In function ‘bxt_ddi_phy_init’:
drivers/gpu/drm/i915/intel_dpio_phy.c:482:25: warning: ‘was_enabled’ may be used uninitialized in this function [-Wmaybe-uninitialized]

In this case, we can rearrange code slightly to make the control flow
clearer to the reader, as well as the compiler. That is we only call
uninit using the same predicate as calling init
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171107135324.28300-1-chris@chris-wilson.co.ukReviewed-by: NGabriel Krisman Bertazi <krisman@collabora.co.uk>

gcc-4.7 is not very smart and can not tell that "si" is guarded by size
being 0. So it complains,

drivers/gpu/drm/i915/intel_csr.c: In function ‘csr_load_work_fn’:
drivers/gpu/drm/i915/intel_csr.c:204:3: warning: ‘si’ may be used uninitialized in this function [-Wmaybe-uninitialized]
drivers/gpu/drm/i915/intel_csr.c:190:30: note: ‘si’ was declared in

Give in and mark si as NULL.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171107145334.27154-1-chris@chris-wilson.co.ukReviewed-by: NGabriel Krisman Bertazi <krisman@collabora.co.uk>
Reviewed-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>

drivers/gpu/drm/i915/i915_cmd_parser.c:808:23: error: not an lvalue
drivers/gpu/drm/i915/i915_cmd_parser.c:811:23: error: not an lvalue
drivers/gpu/drm/i915/i915_cmd_parser.c:814:23: error: not an lvalue
drivers/gpu/drm/i915/i915_cmd_parser.c:808:23: error: not an lvalue
drivers/gpu/drm/i915/i915_cmd_parser.c:811:23: error: not an lvalue
drivers/gpu/drm/i915/i915_cmd_parser.c:814:23: error: not an lvalue
drivers/gpu/drm/i915/i915_cmd_parser.c:808:23: error: not an lvalue
drivers/gpu/drm/i915/i915_cmd_parser.c:811:23: error: not an lvalue
drivers/gpu/drm/i915/i915_cmd_parser.c:814:23: error: not an lvalue
drivers/gpu/drm/i915/i915_cmd_parser.c:808:23: error: not an lvalue
drivers/gpu/drm/i915/i915_cmd_parser.c:811:23: error: not an lvalue
drivers/gpu/drm/i915/i915_cmd_parser.c:814:23: error: not an lvalue

If we move the shift into each case not only do we kill the warning from
smatch, but we shrink the code slightly:

   text	   data	    bss	    dec	    hex	filename
1267906	  20587	   3168	1291661	 13b58d	before
1267890	  20587	   3168	1291645	 13b57d	after
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171107154055.19460-1-chris@chris-wilson.co.ukReviewed-by: NMatthew Auld <matthew.william.auld@gmail.com>
Reviewed-by: NGabriel Krisman Bertazi <krisman@collabora.co.uk>

gcc-4.4 complains about:

	struct sgt_dma iter = {
		.sg = vma->pages->sgl,
		.dma = sg_dma_address(iter.sg),
		.max = iter.dma + iter.sg->length,
	};

drivers/gpu/drm/i915/i915_gem_gtt.c: In function ‘gen8_ppgtt_insert_4lvl’:
drivers/gpu/drm/i915/i915_gem_gtt.c:938: error: ‘iter.sg’ is used uninitialized in this function
drivers/gpu/drm/i915/i915_gem_gtt.c:939: error: ‘iter.dma’ is used uninitialized in this function

and worse generates invalid code that triggers a GPF:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
IP: gen8_ppgtt_insert_4lvl+0x1b/0x1e0 [i915]
PGD 0
Oops: 0000 [#1] SMP
Modules linked in: snd_aloop nf_conntrack_ipv6 nf_defrag_ipv6 nf_log_ipv6 ip6table_filter ip6_tables ctr ccm xt_state nf_log_ipv4
nf_log_common xt_LOG xt_limit xt_recent xt_owner xt_addrtype iptable_filter ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat
nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack libcrc32c ip_tables dm_mod vhost_net macvtap macvlan vhost tun kvm_intel kvm
irqbypass uas usb_storage hid_multitouch btusb btrtl uvcvideo videobuf2_v4l2 videobuf2_core videodev media videobuf2_vmalloc videobuf2_memops
sg ppdev dell_wmi sparse_keymap mei_wdt sd_mod iTCO_wdt iTCO_vendor_support rtsx_pci_ms memstick rtsx_pci_sdmmc mmc_core dell_smm_hwmon hwmon
dell_laptop dell_smbios dcdbas joydev input_leds hci_uart btintel btqca btbcm bluetooth parport_pc parport i2c_hid
  intel_lpss_acpi intel_lpss pcspkr wmi int3400_thermal acpi_thermal_rel dell_rbtn mei_me mei snd_hda_codec_hdmi snd_hda_codec_realtek
snd_hda_codec_generic ahci libahci acpi_pad xhci_pci xhci_hcd snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device
snd_pcm snd_timer snd soundcore int3403_thermal arc4 e1000e ptp pps_core i2c_i801 iwlmvm mac80211 rtsx_pci iwlwifi cfg80211 rfkill
intel_pch_thermal processor_thermal_device int340x_thermal_zone intel_soc_dts_iosf i915 video fjes
CPU: 2 PID: 2408 Comm: X Not tainted 4.10.0-rc5+ #1
Hardware name: Dell Inc. Latitude E7470/0T6HHJ, BIOS 1.11.3 11/09/2016
task: ffff880219fe4740 task.stack: ffffc90005f98000
RIP: 0010:gen8_ppgtt_insert_4lvl+0x1b/0x1e0 [i915]
RSP: 0018:ffffc90005f9b8c8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8802167d8000 RCX: 0000000000000001
RDX: 00000000ffff7000 RSI: ffff880219f94140 RDI: ffff880228444000
RBP: ffffc90005f9b948 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000080
R13: 0000000000000001 R14: ffffc90005f9bcd7 R15: ffff88020c9a83c0
FS:  00007fb53e1ee920(0000) GS:ffff88024dd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 000000022ef95000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  ppgtt_bind_vma+0x40/0x50 [i915]
  i915_vma_bind+0xcb/0x1c0 [i915]
  __i915_vma_do_pin+0x6e/0xd0 [i915]
  i915_gem_execbuffer_reserve_vma+0x162/0x1d0 [i915]
  i915_gem_execbuffer_reserve+0x4fc/0x510 [i915]
  ? __kmalloc+0x134/0x250
  ? i915_gem_wait_for_error+0x25/0x100 [i915]
  ? i915_gem_wait_for_error+0x25/0x100 [i915]
  i915_gem_do_execbuffer+0x2df/0xa00 [i915]
  ? drm_malloc_gfp.clone.0+0x42/0x80 [i915]
  ? path_put+0x22/0x30
  ? __check_object_size+0x62/0x1f0
  ? terminate_walk+0x44/0x90
  i915_gem_execbuffer2+0x95/0x1e0 [i915]
  drm_ioctl+0x243/0x490
  ? handle_pte_fault+0x1d7/0x220
  ? i915_gem_do_execbuffer+0xa00/0xa00 [i915]
  ? handle_mm_fault+0x10d/0x2a0
  vfs_ioctl+0x18/0x30
  do_vfs_ioctl+0x14b/0x3f0
  SyS_ioctl+0x92/0xa0
  entry_SYSCALL_64_fastpath+0x1a/0xa9
RIP: 0033:0x7fb53b4fcb77
RSP: 002b:00007ffe0c572898 EFLAGS: 00003246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fb53e17c038 RCX: 00007fb53b4fcb77
RDX: 00007ffe0c572900 RSI: 0000000040406469 RDI: 000000000000000b
RBP: 00007fb5376d67e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000028 R11: 0000000000003246 R12: 0000000000000000
R13: 0000000000000000 R14: 000055eecb314d00 R15: 000055eecb315460
Code: 0f 84 5d ff ff ff eb a2 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 ec 58 0f 1f 44 00 00 31 c0 89 4d b0 <4c>
8b 60 10 44 8b 70 0c 48 89 d0 4c 8b 2e 48 c1 e8 27 25 ff 01
RIP: gen8_ppgtt_insert_4lvl+0x1b/0x1e0 [i915] RSP: ffffc90005f9b8c8
CR2: 0000000000000010

Recent gccs, such as 4.9, 6.3 or 7.2, do not generate the warning nor do
they explode on use. If we manually create the struct using locals from
the stack, this should eliminate this issue, and does not alter code
generation with gcc-7.2.

Fixes: 894ccebe ("drm/i915: Micro-optimise gen8_ppgtt_insert_entries()")
Reported-by: NKelly French <kfrench@federalhill.net>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Kelly French <kfrench@federalhill.net>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171106211128.12538-1-chris@chris-wilson.co.ukTested-by: NKelly French <kfrench@federalhill.net>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

Capturing and cleanup and modparams in error state requires
some macro tricks. Move that code into separated functions
for easier maintenance.
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20171026173657.49648-3-michal.wajdeczko@intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

We keep details of GuC and HuC in separate error state struct.
Make GuC log part of it to group all related data together.
Since we are printing uC details at the end, with this change
GuC log will be moved there too.

v2: comment on new placement of the log (Chris)
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171026173657.49648-2-michal.wajdeczko@intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Include GuC and HuC firmware details in captured error state
to provide additional debug information. To reuse existing
uc firmware pretty printer, introduce new drm-printer variant
that works with our i915_error_state_buf output. Also update
uc firmware pretty printer to accept const input.

v2: don't rely on current caps (Chris)
    dump correct fw info (Michal)
v3: simplify capture of custom paths (Chris)
v4: improve 'why' comment (Joonas)
    trim output if no fw path (Michal)
    group code around uc error state (Michal)
v5: use error in cleanup_uc (Michal)
Suggested-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171026173657.49648-1-michal.wajdeczko@intel.com
[ickle: allow printing uc_fw after allocation failure]
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Silence smatch by demonstrating that ctch->vma is allocated
following a successful chch_init()

drivers/gpu/drm/i915/intel_guc_ct.c:204 ctch_open() error:
 we previously assumed 'ctch->vma' could be null (see line 197)
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171106135154.52520-1-michal.wajdeczko@intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Silence smatch by demonstrating that guc->stage_desc_pool is allocated
following a successful guc_stage_desc_pool_create(),

drivers/gpu/drm/i915/i915_guc_submission.c:1293 i915_guc_submission_init() error: we previously assumed 'guc->stage_desc_pool' could be null (see line 1261)
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171106114833.31199-1-chris@chris-wilson.co.ukReviewed-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>

An oversight in commit 87701b4b ("drm/i915: Only free the oldest
stale object before a fresh allocation") was that not only do we have to
serialise concurrent users of llist_del_first(), but we also have to
lock llist_del_first() vs llist_del_all().

From llist.h,

 * This can be summarized as follows:
 *
 *           |   add    | del_first |  del_all
 * add       |    -     |     -     |     -
 * del_first |          |     L     |     L
 * del_all   |          |           |     -
 *
 * Where, a particular row's operation can happen concurrently with a column's
 * operation, with "-" being no lock needed, while "L" being lock is needed.

This should hopefully explain:

<4>[   89.287106] general protection fault: 0000 [#1] PREEMPT SMP
<4>[   89.287126] Modules linked in: snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic x86_pkg_temp_thermal intel_powerclamp coretemp i915 crct10dif_pclmul crc32_pclmul ghash_clmulni_intel snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core r8169 mii mei_me mei snd_pcm prime_numbers i2c_hid pinctrl_geminilake pinctrl_intel
<4>[   89.287226] CPU: 2 PID: 23 Comm: ksoftirqd/2 Tainted: G     U          4.14.0-rc8-CI-CI_DRM_3315+ #1
<4>[   89.287247] Hardware name: Intel Corp. Geminilake/GLK RVP2 LP4SD (07), BIOS GELKRVPA.X64.0062.B30.1708222146 08/22/2017
<4>[   89.287270] task: ffff88017ab34ec0 task.stack: ffffc90000128000
<4>[   89.287290] RIP: 0010:llist_add_batch+0x4/0x20
<4>[   89.287301] RSP: 0018:ffffc9000012bdb8 EFLAGS: 00010296
<4>[   89.287314] RAX: ffffffff811017ad RBX: 6e468801a1560000 RCX: ef3e53fceecdeb81
<4>[   89.287330] RDX: 6e468801a1566130 RSI: ffff880103d73d98 RDI: ffff880103d73d98
<4>[   89.287346] RBP: ffffc9000012bdb8 R08: ffff88017ab35780 R09: 0000000000000000
<4>[   89.287361] R10: ffffc9000012bd68 R11: 00000000abb18c3d R12: ffffffffa01369e0
<4>[   89.287377] R13: ffff88017fd1b8f8 R14: ffff88017ab34ec0 R15: 000000000000000a
<4>[   89.287393] FS:  0000000000000000(0000) GS:ffff88017fd00000(0000) knlGS:0000000000000000
<4>[   89.287411] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4>[   89.287424] CR2: 00007ff0c0755018 CR3: 000000016df9b000 CR4: 00000000003406e0
<4>[   89.287440] Call Trace:
<4>[   89.287511]  __i915_gem_free_object_rcu+0x20/0x40 [i915]
<4>[   89.287527]  rcu_process_callbacks+0x27a/0x730
<4>[   89.287544]  __do_softirq+0xc0/0x4ae
<4>[   89.287559]  ? smpboot_thread_fn+0x2d/0x280
<4>[   89.287571]  run_ksoftirqd+0x1f/0x70
<4>[   89.287582]  smpboot_thread_fn+0x18a/0x280
<4>[   89.287595]  kthread+0x114/0x150
<4>[   89.287605]  ? sort_range+0x30/0x30
<4>[   89.287615]  ? kthread_create_on_node+0x40/0x40
<4>[   89.287628]  ret_from_fork+0x27/0x40
<4>[   89.287641] Code: 0d 48 83 ea 01 4c 89 c1 48 83 fa ff 74 12 48 23 0c d7 74 ed 48 c1 e2 06 48 0f bd c9 48 8d 04 0a 5d c3 90 90 90 90 90 55 48 89 e5 <48> 8b 0a 48 89 0e 48 89 c8 f0 48 0f b1 3a 48 39 c1 75 ed 48 85
<1>[   89.287774] RIP: llist_add_batch+0x4/0x20 RSP: ffffc9000012bdb8
<4>[   89.287826] ---[ end trace e775d15174d8ae02 ]---

(Lockless lists are only easy (and lockless) when only using
llist_add/llist_del_all!)

Fixes: 87701b4b ("drm/i915: Only free the oldest stale object before
a fresh allocation")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171106111508.11941-1-chris@chris-wilson.co.ukReviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>