drm/i915: Don't allow overuse of __intel_wait_for_register_fw()

This function should not be called with long timeouts in atomic context.
Annotate it as might_sleep if timeout is longer than 10us.

v2: fix comment (Michal)

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170410121747.209200-1-michal.wajdeczko@intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drm/i915: Drop const qualifiers from params in wait_for_register()

These params are passed by value, const qualifiers are ignored any way.
While around, unify timeout_ms type from long to int.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Suggested-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170410093817.151280-1-michal.wajdeczko@intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drm/i915: Use drm_i915_private directly from debugfs

The void *data passed to debugfs callbacks is actually the
drm_i915_private pointer, so use it thusly and avoid the to_i915(dev)
indirection.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170407194220.821-1-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drm/i915/guc: Use wait_for_register_fw() while waiting for MMIO response

Waiting for the response status in scratch register can be done
using our generic function. Let's use it.

v2: rebased

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Suggested-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170407160145.181328-2-michal.wajdeczko@intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drm/i915: Extend intel_wait_for_register_fw() with fast timeout

In some cases we may want to spend more time in atomic wait than
hardcoded 2us. Let's add additional fast timeout parameter to allow
flexible configuration of atomic timeout before switching into heavy wait.
Add also possibility to return registry value to avoid extra read.

v2: use explicit fast timeout (Tvrtko/Chris)
    allow returning register value (Chris)

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Suggested-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170407160145.181328-1-michal.wajdeczko@intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drm/i915: Fix type of timeout_ms parameter in intel_wait_for_register_fw()

There is no need to specify timeout as unsigned long since this parameter
will be consumed by usecs_to_jiffies() which expects unsigned int only.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170407133212.174608-1-michal.wajdeczko@intel.com
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drm/i915: Insert cond_resched() into i915_gem_free_objects

As we may have very many objects to free, check to see if the task needs
to be rescheduled whilst freeing them.

Suggested-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170407102552.5781-4-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drm/i915: Break up long runs of freeing objects

Before freeing the next batch of objects from the worker, check if the
worker's timeslice has expired and if so, defer the next batch to the
next invocation of the worker.

Suggested-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170407102552.5781-3-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drm/i915: Simplify shrinker locking

By using the same structure for both interruptible and
uninterruptible locking in shrinker code, combined with the
information that mm.interruptible is only being written to, the
code can be greatly simplified.

Also removing the i915_gem_ prefix from the locking functions so
that nobody in their wildest dreams considers exporting them.

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1491562175-27680-1-git-send-email-joonas.lahtinen@linux.intel.com

drm/i915: Don't call synchronize_rcu_expedited under struct_mutex

Only call synchronize_rcu_expedited after unlocking struct_mutex to
avoid deadlock because the workqueues depend on struct_mutex.

>From original patch by Andrea:

synchronize_rcu/synchronize_sched/synchronize_rcu_expedited() will
hang until its own workqueues are run. The i915 gem workqueues will
wait on the struct_mutex to be released. So we cannot wait for a
quiescent state using those rcu primitives while holding the
struct_mutex or it creates a circular lock dependency resulting in
kernel hangs (which is reproducible but goes undetected by lockdep).

kswapd0         D    0   700      2 0x00000000
Call Trace:
? __schedule+0x1a5/0x660
? schedule+0x36/0x80
? _synchronize_rcu_expedited.constprop.65+0x2ef/0x300
? wake_up_bit+0x20/0x20
? rcu_stall_kick_kthreads.part.54+0xc0/0xc0
? rcu_exp_wait_wake+0x530/0x530
? i915_gem_shrink+0x34b/0x4b0
? i915_gem_shrinker_scan+0x7c/0x90
? i915_gem_shrinker_scan+0x7c/0x90
? shrink_slab.part.61.constprop.72+0x1c1/0x3a0
? shrink_zone+0x154/0x160
? kswapd+0x40a/0x720
? kthread+0xf4/0x130
? try_to_free_pages+0x450/0x450
? kthread_create_on_node+0x40/0x40
? ret_from_fork+0x23/0x30
plasmashell     D    0  4657   4614 0x00000000
Call Trace:
? __schedule+0x1a5/0x660
? schedule+0x36/0x80
? schedule_preempt_disabled+0xe/0x10
? __mutex_lock.isra.4+0x1c9/0x790
? i915_gem_close_object+0x26/0xc0
? i915_gem_close_object+0x26/0xc0
? drm_gem_object_release_handle+0x48/0x90
? drm_gem_handle_delete+0x50/0x80
? drm_ioctl+0x1fa/0x420
? drm_gem_handle_create+0x40/0x40
? pipe_write+0x391/0x410
? __vfs_write+0xc6/0x120
? do_vfs_ioctl+0x8b/0x5d0
? SyS_ioctl+0x3b/0x70
? entry_SYSCALL_64_fastpath+0x13/0x94
kworker/0:0     D    0 29186      2 0x00000000
Workqueue: events __i915_gem_free_work
Call Trace:
? __schedule+0x1a5/0x660
? schedule+0x36/0x80
? schedule_preempt_disabled+0xe/0x10
? __mutex_lock.isra.4+0x1c9/0x790
? del_timer_sync+0x44/0x50
? update_curr+0x57/0x110
? __i915_gem_free_objects+0x31/0x300
? __i915_gem_free_objects+0x31/0x300
? __i915_gem_free_work+0x2d/0x40
? process_one_work+0x13a/0x3b0
? worker_thread+0x4a/0x460
? kthread+0xf4/0x130
? process_one_work+0x3b0/0x3b0
? kthread_create_on_node+0x40/0x40
? ret_from_fork+0x23/0x30

Fixes: 3d3d18f086cd ("drm/i915: Avoid rcu_barrier() from reclaim paths (shrinker)")
Reported-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

drm/i915: Drain any freed objects prior to hibernation

As we call into the shrinker during freeze, we may have freed more
objects since we idled during i915_gem_suspend. Make sure we flush the
i915_gem_free_objects worker prior to saving the unwanted pages into the
hibernation image.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170407102552.5781-2-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drm/i915: The shrinker already acquires struct_mutex, so call it unlocked

The shrinker is prepared to be called unlocked (and at other times with
struct_mutex held for DIRECT_RECLAIM) so we can skip acquiring the
struct_mutex prior to calling the shrinker during freeze. This improves
our ability to shrink as we can be more aggressive when we know the
caller isn't holding struct_mutex.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170407102552.5781-1-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

i915: initialize the free_list of the fencing atomic_helper

Just in case the llist model changes and NULL isn't valid
initialization.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170406232347.988-4-aarcange@redhat.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drm/i915: Advance ring->head fully when idle

When we retire the last request on the ring, before we ever access that
ring again we know it will be completely idle and so we can advance the
ring->head fully to the end (i.e. ring->tail) and not just to the start
of the breadcrumb. This allows us to skip re-emitting the breadcrumb
after resetting the GPU if the ring was entirely idle. This prevents us
from overwriting a seqno wraparound by re-executing a stale breadcrumb,
i.e.
submit_request(1)
intel_engine_init_global_seqno(0)
i915_reset()
would then leave 1 in the HWS, but the next request to execute would
also be with seqno 1. The sanity checks upon submission detect this as a
timewarp and explode. By setting the ring as empty, upon reset the HWS
is left as 0, leaving it consistent with the timeline.

v2: Fix check for deleting last element of list. We know that this
request is always the first element of the ring, so only if next
points back to the start will this be the only request in flight.
v3: Remove opencoding of list_is_last()
v4: Move the block to its own function for some clarity.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100144
Testcase: igt/gem_exec_whisper/hang-*
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170406170028.26871-1-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drm/i915: Assert the engine is idle before overwiting the HWS

When we update the global seqno (on the engine timeline), we modify HW
state (both registers and mapped pages). As we do this, we should be
sure that the HW is idle and we are not causing a conflict. The caller
is supposed to wait_for_idle before calling us to update the seqno, so
let's assert they have and the engine is indeed idle.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170405153055.28123-1-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drm/i915/GLK/HuC: Load HuC on GLK

Load HuC version 1.07.1748 on GLK.

v2: rebased.
v3: Use name of the right platform(John Spotswood)
v4: rebased.

Cc: Jeff Mcgee <jeff.mcgee@intel.com>
Cc: John Spotswood <john.a.spotswood@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
Reviewed-by: John Spotswood <john.a.spotswood@intel.com>
Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1490905447-15815-2-git-send-email-anusha.srivatsa@intel.com

drm/i915/GuC/GLK: Load GuC on GLK

Load GuC 10.56 on GLK. Work on firmware is still
in progress. Testing has not been done yet.
This patch addresses the initial need to load the GuC
firmware for HuC authentication

v2: rebased.

Cc: Jeff mcgee <jeff.mcgee@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: John Spotswood <john.a.spotswood@intel.com>
Signed-off-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
Reviewed-by: John Spotswood <john.a.spotswood@intel.com>
Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1490905447-15815-1-git-send-email-anusha.srivatsa@intel.com

drm/i915: Use the right mapping_gfp_mask for final shmem allocation

Many sightings report the greater prevalence of allocation failures.
This is all due to the incorrect use of mapping_gfp_constraint(), so
remove it in favour of just querying the mapping_gfp_mask() which are
the exact gfp_t we wanted in the first place.

We still do expect a higher chance of reporting ENOMEM, as that is the
intention of using __GFP_NORETRY -- to fail rather than oom after having
reclaimed from our bo caches, and having done a direct|kswapd reclaim
pass.

Reported-by: Jason Ekstrand <jason.ekstrand@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100594
Fixes: 24f8e00a8a2e ("drm/i915: Prefer to report ENOMEM rather than incur the oom for gfx allocations")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170405221514.23251-1-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drm/i915/glk: limit pixel clock to 99% of cdclk workaround

As per BSPEC, valid cdclk values for glk are 79.2, 158.4, 316.8 Mhz.
Practically we can achive only 99% of these cdclk values (HW team
checking on this). So cdclk should be calculated for the given pixclk as
per that otherwise it may lead to screen corruption, explained below:
1. For DSI AUO panel(1920x1200 @60) required pixclk is 157100 KHZ
2. glk_calc_cdclk returns 79200 KHZ for this pixclk, For 2PPC it
   will be 158400 KHZ
3. Practically 100% of the cdclk can’t be achieved, so 99% of 158400
   KHZ  = 156816 which is less than the desired pixlclk and causes
   panel corruption.

v2: Rebased to new CDLCK code framework
v3: Addressed review comments from Ander/Jani
    - Add comment in code about 99% usage of CDCLK
    - Calculate max dot clock as well with 99% limit
v4 by Jani:
    - drop superfluous whitespace change
    - rewrite code comments to clarify
v5: Added details of non-working scenario in commit message

Cc: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Madhav Chauhan <madhav.chauhan@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491397463-13637-1-git-send-email-madhav.chauhan@intel.com

drm/i915/dp: generate and cache sink rate array for all DP, not just eDP 1.4

There is some conflation related to sink rates, making this change more
complicated than it would otherwise have to be. There are three changes
here that are rather difficult to split up:

1) Use the intel_dp->sink_rates array for all DP, not just eDP 1.4. We
   initialize it from DPCD on eDP 1.4 like before, but generate it based
   on DP_MAX_LINK_RATE on others. This reduces code complexity when we
   need to use the sink rates; they are all always in the sink_rates
   array.

2) Update the sink rate array whenever we read DPCD, and use the
   information from there. This increases code readability when we need
   the sink rates.

3) Disentangle fallback rate limiting from sink rates. In the code, the
   max rate is a dynamic property of the *link*, not of the *sink*. Do
   the limiting after intersecting the source and sink rates, which are
   static properties of the devices.

This paves the way for follow-up refactoring that I've refrained from
doing here to keep this change as simple as it possibly can.

v2: introduce use_rate_select and handle non-confirming eDP (Ville)

v3: don't clobber cached eDP rates on short pulse (Ville)

Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/071bad76467f8ab2e73f3f61ad52d5a468004c71.1490712890.git.jani.nikula@intel.com

drm/i915/dp: cache source rates at init

We need the source rates array so often that it makes sense to set it
once at init. This reduces function calls when we need the rates, making
the code easier to follow.

Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/aa998882d2b824f671272c60e9d26621ab9d2d17.1490712890.git.jani.nikula@intel.com

drm/i915/dp: rename rate_to_index() to intel_dp_rate_index() and reuse

Rename the function, move it at the top, and reuse in
intel_dp_link_rate_index(). If there was a reason in the past to use
reverse search order here, there isn't now.

The names may be slightly confusing now, but intel_dp_link_rate_index()
will go away in follow-up patches.

v2: Use name intel_dp_rate_index (Dhinakaran)

Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/c7b6197aaa12e368a0d024dc142fa574fd0443a7.1490712890.git.jani.nikula@intel.com

drm/i915/dp: return errors from rate_to_index()

We shouldn't silently use the first element if we can't find the rate
we're looking for. Make rate_to_index() more generally useful, and
fallback to the first element in the caller, with a big warning.

Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/8a6e83b7bf35da0cbbc703ae157944107ff145be.1490712890.git.jani.nikula@intel.com

drm/i915/dp: use known correct array size in rate_to_index

I can't think of a real world bug this could cause now, but this will be
required in follow-up work. While at it, change the parameter order to
be slightly more sensible.

Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/ff5b08f45a72c2247f5326b080027e2f5d8cc4ee.1490712890.git.jani.nikula@intel.com

drm/i915: Suspend GuC prior to GPU Reset during GEM suspend

i915 is currently doing a full GPU reset at the end of
i915_gem_suspend() followed by GuC suspend in i915_drm_suspend(). This
GPU reset clobbers the GuC, causing the suspend request to then fail,
leaving the GuC in an undefined state. We need to tell the GuC to
suspend before we do the direct intel_gpu_reset().

v2: Commit message update. (Chris, Daniele)

Fixes: 1c777c5d1dcd ("drm/i915/hsw: Fix GPU hang during resume from S3-devices state")
Cc: Jeff McGee <jeff.mcgee@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491387710-20553-1-git-send-email-sagar.a.kamble@intel.com
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drm/i915: Enable atomic on VLV/CHV

VLV/CHV watermarks are now able to handle the radiation, so
mark these platforms as ready for atomic.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Suggested-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170303151928.23053-5-ville.syrjala@linux.intel.com
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

drm/i915: Use intel_wm_plane_visible() on VLV/CHV as well

VLV/CHV don't have double buffered watermarks so they need to consider
the cursor visibility as a special case just like ILK-BDW. Let's use
the helper we have for that.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170303151928.23053-4-ville.syrjala@linux.intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

drm/i915: Check for id==PLANE_CURSOR instead of type==DRM_PLANE_TYPE_CURSOR

The VLV/CHV watermark calculation is really interested in the hardware
plane type rather than the plane type (which is more of a software
concept). Let's check plane->id rather plane->type.

No functional changes.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170303151928.23053-3-ville.syrjala@linux.intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

drm/i915/guc: Use GUC prefix for CORE_FAMILY definitions

Almost all other GuC fw definitions are using GUC|guc prefix.
While around, in get_core_family() change explicit WARN into MISSING_CASE
as it looks more appropriate, since GuC support capability we are controlling
by intel_device_info.has_guc flag.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170404133836.125736-1-michal.wajdeczko@intel.com
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drm/i915: Typo fix - 'pipe bpc' to 'pipe bpp'

Noticed this while I was looking at some debug output,
 [drm:intel_hdmi_compute_config [i915]] picking bpc to 12 for HDMI output
 [drm:intel_hdmi_compute_config [i915]] forcing pipe bpc to 36 for HDMI

I believe the second line should be pipe *bpp*

Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491329765-14340-1-git-send-email-dhinakaran.pandiyan@intel.com

drm/i915: Make legacy cursor updates more unsynced

We're clearing the legacy_cursor_update flag before calling
drm_atomic_helper_setup_commit() which means the helper will
wait for the flip to complete before cleaning up the framebuffers.
That's not what we want for the legacy cursor, so let's clear
the flag after setting up the commit.

Also toss in a FIXME about solving these problems in a nicer
way using the fabled vblank workers.

v2: Also unsync with legacy page flips

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Uwe Kleine-König <uwe@kleine-koenig.org>
Cc: Rafael Ristovski <rafael.ristovski@gmail.com>
Fixes: a5509abda48e ("drm/i915: Fix legacy cursor vs. watermarks for ILK-BDW")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170329142123.5923-1-ville.syrjala@linux.intel.com
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

drm/i915/huc: Simplify intel_huc_init_hw()

On last guc/huc cleanup series we've simplified guc init hw
function but missed the one for the huc. While here, change
its signature as we don't care about huc loading status.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Cc: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170331115709.181940-1-michal.wajdeczko@intel.com

drm/i915: Apply a cond_resched() to the saturated signaler

If the engine is continually completing nops, we can saturate the
signaler and keep it working indefinitely. This angers the NMI watchdog!

A good example is to disable semaphores on snb and run igt/gem_exec_nop -
the parallel, multi-engine workloads are more than sufficient to hog the
CPU, preventing the system from even processing ICMP echo replies.

v2: Tvrtko dug into cond_resched() on x86 and found that it only
depended upon preempt_count and not tif_need_resched() - which means
that we would always call schedule() at that point.

Fixes: c81d46138da6 ("drm/i915: Convert trace-irq to the breadcrumb waiter")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170404120531.10737-1-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

drm/i915: Park the signaler before sleeping

If the signal to park arrives before we sleep, then we need to check
kthread_should_park() before sleeping to avoid missing the signal.
Otherwise, if the signal arrives whilst we are processing completed
requests, we will reset the current->state back to TASK_INTERRUPTIBLE
and so miss the wakeup.

Fixes: fe3288b5da2c ("drm/i915: Park the breadcrumbs signaler across a GPU reset")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170403105124.8969-1-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

drm/i915: Remove user-triggerable WARN from i915_gem_object_create

Since this can be triggered by simply attempting a huge object,
a WARN_ON is not appropriate.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170330163130.24141-1-tvrtko.ursulin@linux.intel.com

drm/i915: Onion unwind for intel_init_ring_common()

Rather than call intel_engine_cleanup() with a partially constructed
engine, unwind the error during intel_init_ring_common().

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170403113426.25707-2-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drm/i915: intel_ring.engine is unused

Or rather it is used only by intel_ring_pin() to extract the
drm_i915_private which we can easily pass in. As this is a relatively
rare operation, save the space in the struct, and as such it is even
break even in the extra code for passing around the parameter:

add/remove: 0/0 grow/shrink: 2/3 up/down: 15/-15 (0)
function                                     old     new   delta
intel_init_ring_buffer                       906     918     +12
execlists_context_pin                       1308    1311      +3
mock_engine                                  407     403      -4
intel_engine_create_ring                     367     363      -4
intel_ring_pin                               326     319      -7
Total: Before=1261794, After=1261794, chg +0.00%

v2: Reorder intel_init_ring_buffer to keep the ring setup together:

add/remove: 0/0 grow/shrink: 2/3 up/down: 9/-15 (-6)
function                                     old     new   delta
intel_init_ring_buffer                       906     912      +6
execlists_context_pin                       1308    1311      +3
mock_engine                                  407     403      -4
intel_engine_create_ring                     367     363      -4
intel_ring_pin                               326     319      -7
Total: Before=1261794, After=1261788, chg -0.00%

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170403113426.25707-1-chris@chris-wilson.co.uk

drm/i915: Update DRIVER_DATE to 20170403

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm/i915: Clear gt.active_requests before checking idle status

commit 8490ae207f1d ("drm/i915: Suppress busy status for engines if
wedged") moved the check for inflight requests to the
intel_engines_are_idle() check to protect the idle worker. However, the
request selftests were also checking the engine idle status and erroring
out if they did not become idle within a short period of time after the
final wait. In order to accommodate the new check, call retire requests
prior to the engine check so that we flush all the waits.

Fixes: 8490ae207f1d ("drm/i915: Suppress busy status for engines if wedged")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170331192121.10024-1-chris@chris-wilson.co.uk
Reviewed-by: Matthew Auld <matthew.william.auld@gmail.com>

drm/i915/uc: Drop use of MISSING_CASE on trivial enums

We can rely on compiler to notify us if we miss any case.
This approach may also reduce driver size (reported ~4K).

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170331102652.177664-1-michal.wajdeczko@intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drm/i915: make a few DDI functions static

We don't need to export them since they're not being used outside the
file. The next time I try to find the callers for these things I will
know I won't need to look outside intel_ddi.c.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1490907472-10883-1-git-send-email-paulo.r.zanoni@intel.com

drm/i915: Combine reset_all_global_seqno() loops into one

We can merge the pair of loops over the engines and their timelines into
a single loop, making it easier to read and more consistent with the
commentary.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170330145041.9005-6-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drm/i915: Remove redudant wait for each engine to idle from seqno wrap

Having added the wait upon each engine to idle into the central
i915_gem_wait_for_idle(), we can remove the now redundant wait from
reset_all_global_seqno(). This has the advantage of removing the late
detection of an error (an engine still busy) which left the seqno reset
only partially complete (though it should be safe enough!).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170330145041.9005-5-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drm/i915: Wait for all engines to be idle as part of i915_gem_wait_for_idle()

Make i915_gem_wait_for_idle() be a little heavier in order to try and
guarantee that the GPU is indeed idle (by checking each engine
individually is idle, i.e. all writes are complete and the rings
stopped) after waiting for in-flight requests to be completed.

v2: And return the final error.
v3: Break the wait_for() out from under the WARN -- the macro expansion
is hideous and unreadable in the warning message
v4: If wait_for_engine() fails the result is catastrophic, mark the
device as wedged and wait for the repair team.

References: https://bugs.freedesktop.org/show_bug.cgi?id=98836
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170330145041.9005-4-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drm/i915: Move retire-requests into i915_gem_wait_for_idle()

As we now distinguish everywhere that can call
i915_gem_retire_requests() following a successful wait_for_idle, we can
remove the duplication by moving that call into i915_gem_wait_for_idle()
itself.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170330145041.9005-3-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drm/i915/uc: Move fw path check to fetch_uc_fw()

There is no reason to separately check for valid fw path before
we try to fetch it. Let the fetch function take care of this.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170330112115.120240-2-michal.wajdeczko@intel.com

drm/i915/huc: Remove unused intel_huc_fini()

This function is no longer used. Its functionality is covered
by intel_uc_fini_fw().

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drm/i915/uc: Add intel_uc_fw_fini()

Cleanups of uc firmware structs from GuC and Huc are the same for both.
Move common code to the helper function to avoid duplication.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drm/i915/uc: Add intel_uc_fw_type_repr()

Some of the DRM_NOTE messages are just using "uC" without specifying
which uc they are related to. We can be more user friendly.

v2: moved to the header (Joonas)

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drm/i915/uc: Move intel_uc_fw_status_repr() to intel_uc.h

The file fits better. Also use "<invalid>" for invalid case.

v2: move directly to .h (Joonas)

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drivers: gpu: drm: i915L intel_lpe_audio: Fix kerneldoc comments

Add description for existing parameter 'pipe' to fix the build
warning: ./drivers/gpu/drm/i915/intel_lpe_audio.c:342: warning: No
description found for parameter 'pipe'.

Signed-off-by: Tamara Diaconita <diaconita.tamara@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170330115510.14054-1-diaconita.tamara@gmail.com

drm/i915: Suppress busy status for engines if wedged

If the driver is wedged, HW state may be very inconsistent and
report that it is still busy, even though we have stopped using it. This
can lead to a double *ERROR* rather than a graceful cleanup after
wedging.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170330145041.9005-2-chris@chris-wilson.co.uk

drm/i915: Do request retirement before marking engines as wedged

As we declare an engine as wedged, we mark all of its active requests as
in error. However, we don't want to mark successfully completed requests
as in error, which requires us to retire those requests first.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170330145041.9005-1-chris@chris-wilson.co.uk

drm/i915: Drop verbose and archaic "ring" from our internal engine names

We pretty print the name of an engine in several places, mostly for
debug, but also in the GPU hang report. Using "ring" in the name is
archaic (we call those engines now to differentiate them from the
multiple rings of commands we execute on each engine), quite verbose and
often tautological. We run out of room in our GPU hang report for
instance if we have more than a couple of engines hung simultaneously.
Bit the bullet and update the strings to reflect the common internal names.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170330134820.12273-1-chris@chris-wilson.co.uk

drm/i915: Use a dummy timeline name for a signaled fence

Michał Winiarski pointed out that the debugging infrastructure (such as
trace_dma_fence_release) likes to pretty print the timeline name, long
after we have freed the timeline. Our timelines currently live as part of
the GTT (due to the strict ordering we currently use through each) which
belong to the context. We aim to free the context and release its
hardware resources as soon as we able to (i.e. when the last
fence/request using it has been signaled and retired). As the
.get_timeline_name is purely a debug feature, rather than extending the
lifetime of the context, or splitting it into many different release
phases just to keep the name around, replace the timeline name with a
constant after the fence has been signaled. This avoids the potential
use-after-free.

Reported-by: Krzysztof Olinski <krzysztof.e.olinski@intel.com>
Fixes: 80b204bce8f2 ("drm/i915: Enable multiple timelines")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: <stable@vger.kernel.org> # v4.10+
Link: http://patchwork.freedesktop.org/patch/msgid/20170330111614.29757-1-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Michał Winiarski <michal.winiarski@intel.com>

Merge tag 'gvt-next-2017-03-30' of https://github.com/01org/gvt-linux into drm-intel-next-queued

gvt-next-2017-03-30

- Add mdev attribute group for per-vgpu info
- Time slice based vGPU scheduling QoS support (Gao Ping)
- Initial KBL support for E3 server (Han Xu)
- other misc.

Link: http://patchwork.freedesktop.org/patch/msgid/20170330100516.dkavi3rtlsmnoepi@zhen-hp.sh.intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm/i915: Ironlake do_idle_maps w/a may be called w/o struct_mutex

Since commit 1233e2db199d ("drm/i915: Move object backing storage
manipulation to its own locking"), i915_gem_object_put_pages() and
specifically the i915_gem_gtt_finish_pages() may be called from outside
of the struct_mutex and so we can no longer pass I915_WAIT_LOCKED to
i915_gem_wait_for_idle.

Fixes: 1233e2db199d ("drm/i915: Move object backing storage manipulation to its own locking")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: intel-gfx@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v4.10+
Link: http://patchwork.freedesktop.org/patch/msgid/20170330085341.20311-1-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drm/i915/guc: Take enable_guc_loading check out of GEM core code

The should happen as soon as possible, but always within the logic that
depends on it (and not interrupting the top-level driver control flow).

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Oscar Mateo <oscar.mateo@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1490720027-23234-1-git-send-email-oscar.mateo@intel.com

drm/i915/opregion: debug log about invalid ACPI OpRegion VBT

Leave more breadcrumbs for debuggers.

Reviewed-by: Bob Paauwe <bob.j.paauwe@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1490783578-6065-3-git-send-email-jani.nikula@intel.com

drm/i915/opregion: try to validate RVDA VBT only if it's there

Seems more sensible this way, and reduces indent for the more common
case.

Reviewed-by: Bob Paauwe <bob.j.paauwe@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1490783578-6065-2-git-send-email-jani.nikula@intel.com

drm/i915/opregion: bail out early for systems with no opregion VBT

Reduce indent. No functional changes.

Reviewed-by: Bob Paauwe <bob.j.paauwe@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1490783578-6065-1-git-send-email-jani.nikula@intel.com

drm/i915/gvt: control the scheduler by timeslice usage

The timeslice usage will determine vGPU whether has chance to
schedule or not at every vGPU switch checkpoint.

Signed-off-by: Ping Gao <ping.a.gao@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drm/i915/gvt: create an idle vGPU

vGPU resource is allocated by scheduler. To account for non-allocated
free cycles, we create an idle vGPU as the placeholder similar to idle task
concept, which is useful to handle some corner cases in scheduling policy.

Signed-off-by: Ping Gao <ping.a.gao@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drm/i915/gvt: add basic function for weight control

This method tries to guarantee precision in second level, with the
adjustment conducted in every 100ms. At the end of each vGPU switch
calculate the sched time and subtract it from the time slice
allocated; the allocated time slice for every 100ms together with
remaining timeslice, will be used to decide how much timeslice
allocated to this vGPU in the next 100ms slice, with the end goal
to guarantee weight ratio in second level.

Signed-off-by: Ping Gao <ping.a.gao@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drm/i915/gvt: define weight according to vGPU type

The weight defines proportional control of physical GPU resource
shared between vGPUs. So far the weight is tied to a specific vGPU
type, i.e when creating multiple vGPUs with different types, they
will inherit different weights.

e.g. The weight of type GVTg_V5_2 is 8, the weight of type GVTg_V5_4
is 4, so vGPU of type GVTg_V5_2 has double vGPU resource of vGPU type
GVTg_V5_4.

TODO: allow user control the weight setting in the future.

Signed-off-by: Ping Gao <ping.a.gao@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drm/i915/gvt: factor out the scheduler

Factor out the scheduler to a more clear structure, the basic
logic is to find out next vGPU first and then schedule it.
vGPUs were ordered in a LRU list, scheduler scan from the LRU
list head and choose the first vGPU who has pending workload.

Signed-off-by: Ping Gao <ping.a.gao@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drm/i915/gvt: add some statistic routine for scheduler

Add some statistic routine to collect the time when vGPU is
scheduled in/out and the time of the last ctx submission.

Signed-off-by: Ping Gao <ping.a.gao@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drm/i915/gvt: use hrtimer replace delayed_work in scheduler

Currently the scheduler is triggered by delayed_work, which doesn't
provide precision at microsecond level. Move to hrtimer instead for
more accurate control.

Signed-off-by: Ping Gao <ping.a.gao@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drm/i915/gvt: remove the redundant info NULL check

The variable info is never NULL, which is checked by the caller. This
patch removes the redundant info NULL check logic.

Fixes: 695fbc08d80f ("drm/i915/gvt: replace the gvt_err with gvt_vgpu_err")
Signed-off-by: Tina Zhang <tina.zhang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drm/i915/gvt: adjust mem size for low resolution type

From commit d1a513be1f0a ("drm/i915/gvt: add resolution definition for vGPU
type"), small type has been restricted to small resolution, so not
require larger high GM size any more. Change to smaller 384M for more
VM creation with vGPU enabled which still perform reasonable workload.

Fixes: d1a513be1f0a ("drm/i915/gvt: add resolution definition for vGPU type")
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drm/i915: Use LINEAR modifier instead of NONE

They're the same, so use the one which makes more sense.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Link: http://patchwork.freedesktop.org/patch/msgid/20170324212950.2206-1-ben@bwidawsk.net
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

Revert "drm/i915: Skip execlists_dequeue() early if the list is empty"

This reverts commit 6c943de6686f ("drm/i915: Skip execlists_dequeue()
early if the list is empty").

The validity of using READ_ONCE there depends upon having a mb to
coordinate the assignment of engine->execlist_first inside
submit_request() and checking prior to taking the spinlock in
execlists_dequeue(). We wrote "the update to TASKLET_SCHED incurs a
memory barrier making this cross-cpu checking safe", but failed to
notice that this mb was *conditional* on the execlists being ready, i.e.
there wasn't the required mb when it was most necessary!

We could install an unconditional memory barrier to fixup the
READ_ONCE():

diff --git a/drivers/gpu/drm/i915/intel_lrc.c
b/drivers/gpu/drm/i915/intel_lrc.c
index 7dd732cb9f57..1ed164b16d44 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -616,6 +616,7 @@ static void execlists_submit_request(struct
drm_i915_gem_request *request)

        if (insert_request(&request->priotree, &engine->execlist_queue))
{
                engine->execlist_first = &request->priotree.node;
+               smp_wmb();
                if (execlists_elsp_ready(engine))

But we have opted to remove the race as it should be rarely effective,
and saves us having to explain the necessary memory barriers which we
quite clearly failed at.

Reported-and-tested-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Fixes: 6c943de6686f ("drm/i915: Skip execlists_dequeue() early if the list is empty")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170329100052.29505-1-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>

drm/i915: Avoid lock dropping between rescheduling

Unlocking is dangerous. In this case we combine an early update to the
out-of-queue request, because we know that it will be inserted into the
correct FIFO priority-ordered slot when it becomes ready in the future.
However, given sufficient enthusiasm, it may become ready as we are
continuing to reschedule, and so may gazump the FIFO if we have since
dropped its spinlock. The result is that it may be executed too early,
before its dependencies.

v2: Move all work into the second phase over the topological sort. This
removes the shortcut on the out-of-rbtree request to ensure that we only
adjust its priority after adjusting all of its dependencies.

Fixes: 20311bd35060 ("drm/i915/scheduler: Execute requests in order of priorities")
Testcase: igt/gem_exec_whisper
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: <stable@vger.kernel.org> # v4.10+
Link: http://patchwork.freedesktop.org/patch/msgid/20170327202143.7972-1-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

drm/i915: Move WARN_ON/MISSING_CASE macros to i915_utils.h

We can't sometimes use these macros in other headers due to
include and definition order. As i915_utils.h already contains
other helper macros move these macros there.

v2: checkpatch cleanup for WARN() macro.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170328084513.174200-1-michal.wajdeczko@intel.com
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drm/i915/gvt: remove workload from intel_shadow_wa_ctx structure

intel_shadow_wa_ctx is a field of intel_vgpu_workload. container_of() can
be used to refine the relation-ship between intel_shadow_wa_ctx and
intel_vgpu_workload. This patch removes the useless dereference.

v2. add "drm/i915/gvt" prefix. (Zhenyu)

Signed-off-by: Tina Zhang <tina.zhang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drm/i915/gvt: Turn on KBL platform support.

Turn on KBL WS platform support in gvt-g. More platforms would be
enabled, after validate.

Signed-off-by: Xu Han <xu.han@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drm/i915/gvt: Add KBL dispatch logic in each function.

Extend function dispatch logic to support KBL platform.

Signed-off-by: Xu Han <xu.han@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drm/i915/gvt: Update save/restore list to compatible KBL platform.

Add some KBL specially registers to save/restore list.

Signed-off-by: Xu Han <xu.han@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drm/i915/gvt: Update MMIO handle policy to compatible KBL platform.

Update MMIO handle policy to KBL platform.

Signed-off-by: Xu Han <xu.han@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drm/i915/gvt: Add KBL platform definition.

Add KBL platform definition.

Signed-off-by: Xu Han <xu.han@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drm/i915/gvt: Add mdev device attribute group

This adds initial attribute group for mdev to hold vGPU related
for each mdev device, currently just vGPU id is shown.

v2: rename group name as "intel_vgpu"

Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>

drm/i915/gvt: make dpcd_fix_data supports DP1.2

GVT-g will emulate a fixed DPCD data to VM for DP/eDP panel. Update
this data to latest DP1.2 with the maximum lane bandwidth of 5.4G/s
to support 4K resolution in VM.

V3: modify patch comment
V2: add inline comment to describe the dpcd_fix_data.

Signed-off-by: Pei Zhang <pei.zhang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drm/i915/gvt: emulate SKL_FUSE_STATUS and LCPLL_CTL for virtual monitor detection

Initialize the correct vreg for virtual monitor.
Set PG0/1/2 distribution and fuse download done in SKL_FUSE_STATUS.
Set PLL_ENABLE and PLL_LOCK in LCPLL_CTL.
Guest may need to check these registers for display monitor detection
on Skylake platforms.

Signed-off-by: Weinan Li <weinan.z.li@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

Merge remote-tracking branch 'airlied/drm-next' into drm-intel-next-queued

Backmerge drm-next one more because Dave fumbled the conflict
resolution slightly and I didn't notice it. We need Zhenyu's hotfix
before he can assemble the gvt pull ...

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

drm/i915/gvt: fix error return check for copy_gma_to_hva()

From commit 73dec95e6ba3 ("drm/i915: Emit to ringbuffer directly"),
copy_gma_to_hva() now returns copied data length instead of 0, so
need to change error return check for that.

Note: Looks this is caused by backmerge conflict resolving, so
4.11-rc4 is not impacted as commit 73dec95e6ba3 ("drm/i915: Emit to
ringbuffer directly") is not in 4.11. But need to fix this before I
can apply 4.12 stuff against drm-intel-next correctly.

Fixes: e5c1ff14757a ("Backmerge tag 'v4.11-rc4' into drm-next")
Cc: Dave Airlie <airlied@redhat.com>
Cc: Tina Zhang <tina.zhang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drm/i915/dp: reduce link M/N parameters

Several major vendor USB-C->HDMI converters, in particular the DA200,
fail to recover a 5.4 GHz 1 lane signal if the link N is greater than
0x80000.

The link M and N depend on the pixel clock and link clock ratio. With
current code link N exceeds 0x80000 only when link clock >= 540000
kHz. Except for the eDP intermediate link clocks, at least the four
least significant bits are always zero. Just one bit shift right would
be enough to bring even the DP 1.4 810000 kHz link clock under 0x80000
link N. The pixel clock for modes that require a link clock >= 540000
kHz would also have several least significant bits zero. Unless the user
provides a mode with an odd pixel clock value, we can reduce the numbers
to reach the goal, with no loss in precision.

The DP spec even mentions sources making choices that "allow for static
and relatively small Mvid and Nvid values", thus reducing the link M/N
regardless of the sink in question seems justified.

Everything here is based on the work and information gathered by Clint
Taylor <clinton.a.taylor@intel.com>. This is just an iteration to reduce
the parameters regardless of lane count, link rate, or sink.

Reference: http://patchwork.freedesktop.org/patch/msgid/1490225256-11667-1-git-send-email-clinton.a.taylor@intel.com
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93578
Tested-by: Mads <mads@ab3.no>
Tested-by: PJ <foobar@pjmodos.net>
Tested-by: François Guerraz <kubrick@fgv6.net>
Tested-by: Lev Popov <leo@nabam.net>
Tested-by: Igor Krivenko <igor.s.krivenko@gmail.com>
Tested-by: Clint Taylor <clinton.a.taylor@intel.com>
Reviewed-by: Clint Taylor <clinton.a.taylor@intel.com>
Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Clint Taylor <clinton.a.taylor@intel.com>
Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1490614405-23337-1-git-send-email-jani.nikula@intel.com

drm/i915: Take rpm wakelock around debugfs/i915_gpu_info

Capturing GPU state requires the device to be awake in order to read
registers. Normally, this is taken along the error handler, but for the
direct debugfs access, we cannot make assumptions about the current
device state and so either need to wake it up, or abort.

Fixes: 5a4c6f1b1b2d ("drm/i915: The return of i915_gpu_info to debugfs")
Testcase: igt/pm_rpm/debugfs-read
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170328131407.14863-1-chris@chris-wilson.co.uk
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>

drm/i915: WARN if the core runtime PM get helpers fail

We don't expect the core runtime PM get helpers to return any error, so
add a WARN for this. Also print the return value for all the callsites
to help debugging.

v2:
- Don't call pm_runtime_get_sync() as part of initing locals. (Chris)

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1490693935-12638-1-git-send-email-imre.deak@intel.com

drm/i915/perf: remove user triggerable warn

Don't throw a warning if we are given an invalid property id. While
here let's also bring back Robert' original idea of catching unhandled
enumeration values at compile time.

Fixes: eec688e1420d ("drm/i915: Add i915 perf infrastructure")
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Robert Bragg <robert@sixbynine.org>
Reviewed-by: Robert Bragg <robert@sixbynine.org>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170327203236.18276-1-matthew.auld@intel.com

drm/i915: update the firmware download URL

The old URL works but gives 301 Moved Permanently. Update.

Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1489574966-27200-1-git-send-email-jani.nikula@intel.com

Merge remote-tracking branch 'airlied/drm-next' into drm-intel-next-queued

Backmerge drm-next to get at -rc4, which we need to land the 4.12 gvt
patches.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

Backmerge tag 'v4.11-rc4' into drm-next

Linux 4.11-rc4

The i915 GVT team need the rc4 code to base some more code on.

drm/i915/perf: destroy stream on sample_flags mismatch

If we were to ever encounter a sample_flags mismatch we need to ensure
we destroy the stream when we bail.

Fixes: d79651522e89 ("drm/i915: Enable i915 perf stream for Haswell OA unit")
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Robert Bragg <robert@sixbynine.org>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170327203459.18398-1-matthew.auld@intel.com

drm/i915: allow HDMI 2.0 clock rates

Geminilake has a native HDMI 2.0 controller, which is capable of
driving clocks upto 594Mhz. This patch updates the max tmds clock
limit for the same.

V2: rebase
V3: rebase
V4: added r-b from Ander
V5: rebase
V6: rebase
V7: rebase
V8: rebase
V9: rebase
V10: rebase

Cc: Ander Conselvan De Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
Reviewed-by: Ander Conselvan De Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1489404244-16608-7-git-send-email-shashank.sharma@intel.com

drm/i915: enable scrambling

Geminilake platform sports a native HDMI 2.0 controller, and is
capable of driving pixel-clocks upto 594Mhz. HDMI 2.0 spec
mendates scrambling for these higher clocks, for reduced RF footprint.

This patch checks if the monitor supports scrambling, and if required,
enables it during the modeset.

V2: Addressed review comments from Ville:
 - Do not track scrambling status in DRM layer, track somewhere in
   driver like in intel_crtc_state.
 - Don't talk to monitor at such a low layer, set monitor scrambling
   in intel_enable_ddi() before enabling the port.

V3: Addressed review comments from Jani
 - In comments, function names, use "sink" instead of "monitor",
   so that the implementation could be close to the language of
   HDMI spec.

V4: Addressed review comment from Maarten
 - scrambling -> hdmi_scrambling
 - high_tmds_clock_ratio -> hdmi_high_tmds_clock_ratio

V5: Addressed review comments from Ville and Ander
 - Do not modifiy the crtc_state after compute_config. Move all
   scrambling and tmds_clock_ratio calcutations to compute_config.
 - While setting scrambling for source/sink, do not check the
   conditions again, just go by the crtc_state flags. This will
   simplyfy the condition checks.

V6: Addressed review comments from Ville
 - Do not add IS_GLK check in disable/enable function, instead add it
   in compute_config, while setting state flags.
 - Remove unnecessary paranthesis.
 - Simplyfy handle_sink_scrambling function as suggested.
 - Add readout code for scrambling status in get_ddi_config and add a
   check for the same in pipe_config_compare.

V7: Addressed review comments from Ander/Ville
 - No separate function for source scrambling, make it inline
 - Align the last line of the macro TRANS_DDI_HDMI_SCRAMBLING_MASK
 - Do not add platform check while setting source scrambling
 - Use pipe_config instead of crtc->config to set sink scrambling
 - To readout scrambling status, Compare with SCRAMBLING_MASK
   not any of its bits
 - Remove platform check in intel_pipe_config_compare while checking
   scrambling status

V8: Fixed mege conflict, Addressed review comments from Ander
 - Remove the desciption/comment about scrambling fom the caller, move
   it to the function
 - Move the IS_GLK check into scrambling function
 - Fix alignment

V9: Fixed review comments from Ville, Ander
 - Pass the scrambling state variables as bool input to the sink_scrambling
   function and let the disable call be unconditional.
 - Fix alignments in function calls and debug messages.
 - Add kernel doc for function intel_hdmi_handle_sink_scrambling

V10: Rebase

Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
Reviewed-by: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1489404244-16608-6-git-send-email-shashank.sharma@intel.com

drm/i915: kill intel_ddi_pll_select()

All it does is pick the encoder and call intel_get_shared_dpll(). We
can just do this in the caller. One less indirection level during code
reading.

As another plus, now the two callers of intel_get_shared_dpll() are
{ironlake,haswell}_crtc_compute_clock().

Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1490209125-20046-2-git-send-email-paulo.r.zanoni@intel.com

drm/i915: Mark manually wedged engines as guilty

Use the incoming value from debugfs/i915_wedged to select which engines
to marked as guilty in order to force us to reset those requests
(required to quickly bypass simulated hangs).

Testcase: igt/gem_exec_capture
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170325134735.30581-1-chris@chris-wilson.co.uk
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>

drm/i915: Refactor tests for validity of RING_TAIL

Whilst I like having the assertions clearly visible in the code, they
are quite repetitious! As we find new limits we want to incorporate into
the set of assertions, it make sense to refactor them to a common
routine.

v2: Add a guc holdout.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170327131412.20293-1-chris@chris-wilson.co.uk
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>

drm/i915: Assert that the request->tail fits within the ring

In addition to being qword-aligned, the RING_TAIL offset must be within
the ring!

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170327130009.4678-2-chris@chris-wilson.co.uk
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>

drm/i915/execlists: Wrap tail pointer after reset tweaking

If the request->wa_tail is 0 (because it landed exactly on the end of
the ringbuffer), when we reconstruct request->tail following a reset we
fill in an illegal value (-8 or 0x001ffff8). As a result, RING_HEAD is
never able to catch up with RING_TAIL and the GPU spins endlessly. If
the ring contains a couple of breadcrumbs, even our hangcheck is unable
to catch the busy-looping as the ACTHD and seqno continually advance.

v2: Move the wrap into a common intel_ring_wrap().

Fixes: a3aabe86a340 ("drm/i915/execlists: Reinitialise context image after GPU hang")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: <stable@vger.kernel.org> # v4.10+
Link: http://patchwork.freedesktop.org/patch/msgid/20170327130009.4678-1-chris@chris-wilson.co.uk
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>