There are certain types of interrupts which Host can receive from GuC.
GuC ukernel sends an interrupt to Host for certain events, like for
example retrieve/consume the logs generated by ukernel.
This patch adds support to receive interrupts from GuC but currently
enables & partially handles only the interrupt sent by GuC ukernel.
Future patches will add support for handling other interrupt types.

v2:
- Use common low level routines for PM IER/IIR programming (Chris)
- Rename interrupt functions to gen9_xxx from gen8_xxx (Chris)
- Replace disabling of wake ref asserts with rpm get/put (Chris)

v3:
- Update comments for more clarity. (Tvrtko)
- Remove the masking of GuC interrupt, which was kept masked till the
  start of bottom half, its not really needed as there is only a
  single instance of work item & wq is ordered. (Tvrtko)

v4:
- Rebase.
- Rename guc_events to pm_guc_events so as to be indicative of the
  register/control block it is associated with. (Chris)
- Add handling for back to back log buffer flush interrupts.

v5:
- Move the read & clearing of register, containing Guc2Host message
  bits, outside the irq spinlock. (Tvrtko)

v6:
- Move the log buffer flush interrupt related stuff to the following
  patch so as to do only generic bits in this patch. (Tvrtko)
- Rebase.

v7:
- Remove the interrupts_enabled check from gen9_guc_irq_handler, want to
  process that last interrupt also before disabling the interrupt, sync
  against the work queued by irq handler will be done by caller disabling
  the interrupt.
Signed-off-by: NSagar Arun Kamble <sagar.a.kamble@intel.com>
Signed-off-by: NAkash Goel <akash.goel@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

So far PM IER/IIR/IMR registers were being used only for Turbo related
interrupts. But interrupts coming from GuC also use the same set.
As a precursor to supporting GuC interrupts, added new low level routines
so as to allow sharing the programming of PM IER/IIR/IMR registers between
Turbo & GuC.
Also similar to PM IMR, maintaining a bitmask for PM IER register, to allow
easy sharing of it between Turbo & GuC without involving a rmw operation.

v2:
- For appropriateness & avoid any ambiguity, rename old functions
  enable/disable pm_irq to mask/unmask pm_irq and rename new functions
  enable/disable pm_interrupts to enable/disable pm_irq. (Tvrtko)
- Use u32 in place of uint32_t. (Tvrtko)

v3:
- Rename the fields pm_irq_mask & pm_ier_mask and do some cleanup. (Chris)
- Rebase.

v4: Fix the inadvertent disabling of User interrupt for VECS ring causing
    failure for certain IGTs.

v5: Use dev_priv with HAS_VEBOX macro. (Tvrtko)
Suggested-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NAkash Goel <akash.goel@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

So far there were 2 fields related to GuC logs in 'intel_guc' structure.
For the support of capturing GuC logs & storing them in a local buffer,
multiple new fields would have to be added. This warrants a separate
structure to contain the fields related to GuC logging state.
Added a new structure 'intel_guc_log' and instance of it inside
'intel_guc' structure.

v2: Rebase.
Signed-off-by: NAkash Goel <akash.goel@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

The first page of the GuC log buffer contains state info or meta data
which is required to parse the logs contained in the subsequent pages.
The structure representing the state info is added to interface file
as Driver would need to handle log buffer flush interrupts from GuC.
Added an enum for the different message/event types that can be send
by the GuC ukernel to Host.
Also added 2 new Host to GuC action types to inform GuC when Host has
flushed the log buffer and forcefuly cause the GuC to send a new
log buffer flush interrupt.

v2:
- Make documentation of log buffer state structure more elaborate &
  rename LOGBUFFERFLUSH action to LOG_BUFFER_FLUSH for consistency.(Tvrtko)

v3: Add GuC log buffer layout diagram for more clarity.
Signed-off-by: NSagar Arun Kamble <sagar.a.kamble@intel.com>
Signed-off-by: NAkash Goel <akash.goel@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

GuC Log buffer allocation was tied up with verbosity level module param
i915.guc_log_level. User would be given a provision to enable firmware
logging at runtime, through a host2guc action, and not necessarily during
Driver load time. But the address of log buffer can be passed only in
init params, at firmware load time, so GuC has to be reset and firmware
needs to be reloaded to pass the log buffer address at runtime.
To avoid reset of GuC & reload of firmware, allocation of log buffer will
be done always but logging would be enabled initially on GuC side based on
the value of module parameter guc_log_level.

v2: Update commit message to describe the constraint with allocation of
    log buffer at runtime. (Tvrtko)

v3: Rebase.
Signed-off-by: NSagar Arun Kamble <sagar.a.kamble@intel.com>
Signed-off-by: NAkash Goel <akash.goel@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

Its size is 11:0 instead of 10:0. Found by inspecting the spec. I'm
not aware of any real-world IGT failures caused by this.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477065346-13736-2-git-send-email-paulo.r.zanoni@intel.com

Broadwell and newer actually compress up to 2560 lines instead of 2048
(as documented in the FBC_CTL page). If we don't take this into
consideration we end up reserving too little stolen memory for the
CFB, so we may allocate something else (such as a ring) right after
what we reserved, and the hardware will overwrite it with the contents
of the CFB when FBC is active, causing GPU hangs. Another possibility
is that the CFB may be allocated at the very end of the available
space, so the CFB will overlap the reserved stolen area, leading to
FIFO underruns.

This bug has always been a problem on BDW (the only affected platform
where FBC is enabled by default), but it's much easier to reproduce
since the following commit:
    commit c58b735f
    Author: Chris Wilson <chris@chris-wilson.co.uk>
    Date:   Thu Aug 18 17:16:57 2016 +0100
        drm/i915: Allocate rings from stolen

Of course, you can only reproduce the bug if your screen is taller
than 2048 lines.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98213
Fixes: a98ee793 ("drm/i915/fbc: enable FBC by default on HSW and BDW")
Cc: <stable@vger.kernel.org> # v4.6+
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477065346-13736-1-git-send-email-paulo.r.zanoni@intel.com

At the moment, we have dependency on the RPM as a barrier itself in both
i915_gem_release_all_mmaps() and i915_gem_restore_fences().
i915_gem_restore_fences() is also called along !runtime pm paths, but we
can move the markup of lost fences alongside releasing the mmaps into a
common i915_gem_runtime_suspend(). This has the advantage of locating
all the tricky barrier dependencies into one location.

v2: Just mark the fence as invalid (fence->dirty) so that upon waking we
will be sure to clear the fence after use, or restore it to the correct
value before use. This makes sure that if the fence is left intact
across the sleep, we do not leave it pointing to a region of GTT for the
next unsuspecting user.
Suggested-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Imre Deak <imre.deak@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161024124218.18252-5-chris@chris-wilson.co.uk

We only used the RPM sequence checking inside the lowlevel GTT
accessors, when we had to rely on callers taking the wakeref on our
behalf. Now that we take the RPM wakeref inside the GTT management
routines themselves, we can forgo the sanitycheck of the callers.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Imre Deak <imre.deak@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161024124218.18252-4-chris@chris-wilson.co.uk

Now that we have reduced the access to the list to either (a) under the
struct_mutex whilst holding the RPM wakeref (so that concurrent writers to
the list are serialised by struct_mutex) and (b) under the atomic
runtime suspend (which cannot run concurrently with any other accessor due
to the atomic nature of the runtime suspend) we can remove the extra
locking around the list itself.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161024124218.18252-3-chris@chris-wilson.co.uk

We can remove the false coupling between RPM and struct mutex by the
observation that we can use the RPM wakeref as the barrier around user
mmap access. That is as we tear down the user's PTE atomically from
within rpm suspend and then to fault in new PTE requires the rpm
wakeref, means that no user access is possible through those PTE without
RPM being awake. Having made that observation, we can then remove the
presumption of having to take rpm outside of struct_mutex and so allow
fine grained acquisition of a wakeref around hw access rather than
having to remember to acquire the wakeref early on.

v2: Rejig placement of the new intel_runtime_pm_get() to be as tight
as possible around the GTT pread/pwrite.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161024124218.18252-2-chris@chris-wilson.co.uk

We want to decouple RPM and struct_mutex, but currently RPM has to walk
the list of bound objects and remove userspace mmapping before we
suspend (otherwise userspace may continue to access the GTT whilst it is
powered down). This currently requires the struct_mutex to walk the
bound_list, but if we move that to a separate list and lock we can take
the first step towards removing the struct_mutex.

v2: Split runtime suspend unmapping vs regular unmapping, to make the
locking (and barriers) clearer. Add the object to the userfault_list
prior to inserting the first PTE, the race between add/revoke depends
upon struct_mutex for regular unmappings and rpm for runtime-suspend.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> #v1
Link: http://patchwork.freedesktop.org/patch/msgid/20161024124218.18252-1-chris@chris-wilson.co.uk

We haven't required AGP since 3e99a6b9 ("drm/i915: Stop depending
upon CONFIG_AGP_INTEL"). Split/rearrange the paragraphs a bit while at
it.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477041257-8219-1-git-send-email-jani.nikula@intel.com

The previous code would wait for fences on the framebuffer from the old
plane state to complete, rather than the new, so you would see tearing
everywhere. Fix this to wait on the new state before we make it active.
Signed-off-by: NDaniel Stone <daniels@collabora.com>
Fixes: 94f05024 ("drm/i915: nonblocking commit")
Cc: stable@vger.kernel.org
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161021144454.6288-1-daniels@collabora.com

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

The min-freq-table is an array of values that match each CPU frequency to
an equivalent GPU frequency. Setting a single value of 0 on init is both
illegal (generates an error from the PCU) and nonsensical. Let's see if
we survive without that error.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20161021205531.8651-1-chris@chris-wilson.co.ukReviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

On certain platforms not all planes support the same set of
rotations/reflections, so let's use the per-plane property
for this.

This is already a problem on SKL when we use the legay cursor plane
as it only supports 0|180 whereas the universal planes support
0|90|180|270, and it will be a problem on CHV soon.

v2: Use drm_plane_create_rotation_property() helper
v3: Drop the BIT(), use INTEL_GEN()
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v1)
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1474907460-10717-12-git-send-email-ville.syrjala@linux.intel.com

We have intel_rotation_90_or_270() in i915 to check if the rotation is
90 or 270 degrees. Similar checks are elsewhere in drm, so let's move
the helper into a central place and use it everwhere.

v2: Drop the BIT()
    Convert all new intel_rotation_90_or_270() calls
    Deal with superfluous code shuffling
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v1)
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1474907460-10717-2-git-send-email-ville.syrjala@linux.intel.com

Currently it's entirely possible to go through the link training step
without first determining the lane_count, which is silly since we end up
doing a bunch of aux transfers of size = 0, as highlighted by
WARN_ON(!msg->buffer != !msg->size), and can only ever result in a
'failed to update link training' message. This can be observed during
intel_dp_long_pulse where we can do the link training step, but before
we have had a chance to set the link params. To avoid this we add an
extra check for the lane_count in intel_dp_check_link_status, which
should prevent us from doing the link training step prematurely.

v2: add WARN_ON_ONCE and FIXME comment (Ville)

References: https://bugs.freedesktop.org/show_bug.cgi?id=97344
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: NMatthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476912593-10019-1-git-send-email-matthew.auld@intel.comSigned-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

Fix the poorly indented port parameters to the aux ctl and data
reg functions. This was fallout from the s/i915_mmio_reg_t/i915_reg_t/
that happened during the review of commit f0f59a00 ("drm/i915:
Type safe register read/write")
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476208368-5710-5-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NJim Bride <jim.bride@linux.intel.com>

Now that we use the AUX and GMBUS assignment from VBT for all ports,
let's clean up the sanitization of the port information a bit.
Previosuly we only did this for port E, and only complained about a
non-standard assignment for the other ports. But as we know that
non-standard assignments are a fact of life, let's expand the
sanitization to all the ports.

v2: Include a commit message, fix up the comments a bit
v3: Don't clobber other ports if the current port has no alternate aux ch/ddc pin

Cc: stable@vger.kernel.org
Cc: Maarten Maathuis <madman2003@gmail.com>
Tested-by: NMaarten Maathuis <madman2003@gmail.com>
References: https://bugs.freedesktop.org/show_bug.cgi?id=97877Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476208368-5710-4-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Jim Bride <jim.bride@linux.intel.com> (v2)

The VBT provides the platform a way to mix and match the DDI ports vs.
GMBUS pins. Currently we only trust the VBT for DDI E, which I suppose
has no standard GMBUS pin assignment. However, there are machines out
there that use a non-standard mapping for the other ports as well.
Let's start trusting the VBT on this one for all ports on DDI platforms.

I've structured the code such that other platforms could easily start
using this as well, by simply filling in the ddi_port_info. IIRC there
may be CHV system that might actually need this.

v2: Include a commit message, include a debug message during init

Cc: stable@vger.kernel.org
Cc: Maarten Maathuis <madman2003@gmail.com>
Tested-by: NMaarten Maathuis <madman2003@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97877Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476208368-5710-3-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NJim Bride <jim.bride@linux.intel.com>

The VBT provides the platform a way to mix and match the DDI ports vs.
AUX channels. Currently we only trust the VBT for DDI E, which has no
corresponding AUX channel of its own. However it is possible that some
board might use some non-standard DDI vs. AUX port routing even for
the other ports. Perhaps for signal routing reasons or something,
So let's generalize this and trust the VBT for all ports.

For now we'll limit this to DDI platforms, as we trust the VBT a bit
more there anyway when it comes to the DDI ports. I've structured
the code in a way that would allow us to easily expand this to
other platforms as well, by simply filling in the ddi_port_info.

v2: Drop whitespace changes, keep MISSING_CASE() for unknown
    aux ch assignment, include a commit message, include debug
    message during init

Cc: stable@vger.kernel.org
Cc: Maarten Maathuis <madman2003@gmail.com>
Tested-by: NMaarten Maathuis <madman2003@gmail.com>
References: https://bugs.freedesktop.org/show_bug.cgi?id=97877Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476208368-5710-2-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NJim Bride <jim.bride@linux.intel.com>

Dropping WA because it was for early steppings.

It is fixed in newer preproduction and all production revisions.

v2: add references, updated commit message

References: HSD#2126385, HSD#2131381, BSID#0764
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Signed-off-by: NArkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476977460-28088-1-git-send-email-arkadiusz.hiler@intel.com

According to spec: "KBL re-uses SKL values, except where
specific KBL values are listed."

And recently spec has changed adding different table for Display Port only.
But for all SKUs (H,S,U,Y) we have slightly different values.

v2: Fix wrong condition spotted by Jani.
v3: Fix 7th entry of KBL H and S table - by Manasi.

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NManasi Navare <manasi.d.navare@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476806256-13318-1-git-send-email-rodrigo.vivi@intel.com

No functional change.
Only moving this fixup block out of ddi_translation definitions
so we can split skl and kbl cleanly.

v2: Remove useless comment. (Ville)

Cc: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NManasi Navare <manasi.d.navare@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1475258757-29540-1-git-send-email-rodrigo.vivi@intel.com

If the kernel is old, more than a few releases old, chances are that the
user is using an old kernel for a good reason, despite there being GPU
hangs. After 180days since driver release stop suggesting that they
should send those reports upstream.

[Since Daniel acked this I expect he will pick up the dim patch to
automatically update the DRIVER_TIMESTAMP everytime we tag a new
release.]
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161014134428.29582-1-chris@chris-wilson.co.ukAcked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

As we already capture all the information from the registers into the
error-state, also dumping that to dmesg just generates noise that upsets
CI and users alike (and doesn't provide us with any more information).
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20161019125203.28851-1-chris@chris-wilson.co.ukReviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>

Function create_scratch_page() may fail in some cases.
Signed-off-by: NDu, Changbin <changbin.du@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

The function return values should has type int if it return
a integer value.
Signed-off-by: NDu, Changbin <changbin.du@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

Mark all local functions & variables as static.
Signed-off-by: NDu, Changbin <changbin.du@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

Add proper __iomem annotation for pointers obtained via ioremap().
Signed-off-by: NDu, Changbin <changbin.du@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

Switch to use new for_each_engine() helper to properly access
enabled intel_engine_cs as i915 core has changed that to be
dynamic managed. At GVT-g init time would still depend on ring
mask to determine engine list as it's earlier.
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

This code was removed from i915_cmd_parser.c but still an obsolete
version wound up being duplicated into gvt/cmd_parser.c. Good riddance.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

We have the ability to map an object, so use it rather than opencode it
badly. Note that the object remains permanently pinned, this is poor
practise.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

We have the ability to map an object, so use it rather than opencode it
badly.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

For whatever reason, the gvt scheduler runs synchronously. At the very
least, lets run synchronously without holding the struct_mutex.

v2: cut'n'paste mutex_lock instead of unlock.
Replace long hold of struct_mutex with a mutex to serialise the worker
threads.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

The kthread will not be interrupted, don't even bother checking.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

The workload took a pointer to the request, and even waited upon,
without holding a reference on the request. Take that reference
explicitly and fix up the error path following request allocation that
missed flushing the request.

v2: [zhenyuw]
- drop request put in error path for dispatch, as main thread
caller will handle it identically to a real request.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

Unpinning the pages prior to the object being release from the GPU may
allow the GPU to read and write into system pages (i.e. use after free
by the hw).
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>