Ignore the central i915->kernel_context for allocating an engine, as
that GEM context is being phased out. For internal clients, we just need
the per-engine logical state, so allocate it at the point of use.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190808110612.23539-1-chris@chris-wilson.co.uk

With its original name intel_drv.h the intel_display_types.h header was
superfluously cargo-cult included all over the place, while it's really
mostly about display internals. Remove the unnecessary includes.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/e3d737f0ab87c55969e62c1e077e15c04c238297.1565085692.git.jani.nikula@intel.com

Everything about the file is about display, and mostly about types
related to display. Move under display/ as intel_display_types.h to
reflect the facts.

There's still plenty to clean up, but start off with moving the file
where it logically belongs and naming according to contents.

v2: fix the include guard name in the renamed file
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190806113933.11799-1-jani.nikula@intel.com

To maintain a fast lookup from a GT centric irq handler, we want the
engine lookup tables on the intel_gt. To avoid having multiple copies of
the same multi-dimension lookup table, move the generic user engine
lookup into an rbtree (for fast and flexible indexing).

v2: Split uabi_instance cf uabi_class
v3: Set uabi_class/uabi_instance after collating all engines to provide a
stable uabi across parallel unordered construction.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com> #v2
Link: https://patchwork.freedesktop.org/patch/msgid/20190806124300.24945-2-chris@chris-wilson.co.uk

We do not notify userspace when the scheduler capabilities are changed
(due to wedging the driver) and as such userspace will expect the caps
to be static and unchanging. Make it so, and so we only need to compute
our caps once during driver registration.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190806124300.24945-1-chris@chris-wilson.co.uk

As we increase the number of RCU objects, it becomes easier for us to
have several hundred thousand objects in the deferred RCU free queues.
An example is gem_ctx_create/files which continually creates active
contexts, which are not immediately freed upon close as they are kept
alive by outstanding requests. This lack of backpressure allows the
context objects to persist until they overwhelm and starve the system.
We can increase our backpressure by flushing the freed object queue upon
closing the device fd which should then not impact other clients.

Testcase: igt/gem_ctx_create/*files
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190802212137.22207-2-chris@chris-wilson.co.uk

We don't have to immediately fail on WOPCM partitioning, we can wait
until we will start programming WOPCM registers. This should give us
more options if we decide to restore fallback in case of GuC failures.

v3: rebased
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190802184055.31988-7-michal.wajdeczko@intel.com

Inject probe errors into intel_uc_init_hw to make sure we
correctly handle any uC initialization failure.

To avoid complains from CI about injected errors use
i915_probe_error to lower message level.

v4: rebased after moving hot fixes moved to separate patches
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> #v1
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190802184055.31988-6-michal.wajdeczko@intel.com

With i915 added to i915_inject_probe_failure we can use dedicated
printk when injecting artificial load failure.

Also make this function look like other i915 functions that return
error code and make it more flexible to return any provided error
code instead of previously assumed -ENODEV.
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190802184055.31988-2-michal.wajdeczko@intel.com

We don't call the init_early function from within the gem code, so we
shouldn't do it for the cleanup either.

v2: while at it, s/gt_cleanup_early/gt_late_release (Chris)
v3: s/late_release/driver_late_release/ (Chris)
Signed-off-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> #v1
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190801005709.34092-1-daniele.ceraolospurio@intel.com

Hide the details of MOCS setup from i915_gem by moving both current calls
into one in intel_mocs_init.

Cc: Stuart Summers <stuart.summers@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NLucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: NStuart Summers <stuart.summers@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190713010940.17711-21-lucas.demarchi@intel.com
Link: https://patchwork.freedesktop.org/patch/msgid/20190730180407.5993-6-lucas.demarchi@intel.com

Until Icelake, each engine had its own set of 64 MOCS registers. In
order to simplify, Tigerlake moves to only 64 Global MOCS registers,
which are no longer part of the engine context. Since these registers
are now global, they also only need to be initialized once.

>From Gen12 onwards, MOCS must specify the target cache (3:2) and LRU
management (5:4) fields and cannot be programmed to 'use the value from
Private PAT', because these fields are no longer part of the PPAT. Also
cacheability control (1:0) field has changed, 00 no longer means 'use
controls from page table', but uncacheable (UC).

v2 (Lucas):
    - Move the changes to the fault registers to a separate commit - the
      old ones overlap with the range used by the new global MOCS
      (requested by Daniele)
v3 (Lucas):
    - Clarify comment about setting the unused entries to the same value
      of index 0, that is the invalid entry (requested by Daniele)
    - Move changes to DONE_REG and ERROR_GEN6 to a separate commit
      (requested by Daniele)

Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: NMichel Thierry <michel.thierry@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NLucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: NTomasz Lis <tomasz.lis@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190730180407.5993-5-lucas.demarchi@intel.com

The register we write are not WOPCM regs but uC ones related to how
GuC and HuC are going to use the WOPCM, so it makes logical sense
for them to be programmed as part of uc_init_hw. The WOPCM map on the
other side is not uC-specific (although that is our main use-case), so
keep that separate.

v2: move write_and_verify to uncore, fix log, re-use err_out tag,
    add intel_wopcm_guc_base, fix log
Signed-off-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190730230743.19542-2-daniele.ceraolospurio@intel.com

We only use the init_context vfunc once while recording the default
context state, and we use the same sequence in each backend (eliding
steps that do not apply). Remove the vfunc for simplicity and
de-duplication.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190729113720.24830-1-chris@chris-wilson.co.uk

If the system is already idle, omit the GEM_TRACE saying we are about to
wait for idle. It looks confusing in the logs to see a continual stream
of wait-for-idle, as one immediately assumes it is stuck in a loop.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NStuart Summers <stuart.summers@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190723091218.5886-1-chris@chris-wilson.co.uk

As recently disovered by forcing big-core (!llc) machines to use the GTT
paths, we need our full GTT write flush before manipulating the GTT PTE
or else the writes may be directed to the wrong page.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190718145407.21352-2-chris@chris-wilson.co.uk

Inside pread, we only ever read from the GTT so the serialising wmb()
instructions around the GGTT PTE updates are pointless.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190718145407.21352-1-chris@chris-wilson.co.uk

All the intel_uc_* can now be moved to work on the intel_uc structure
for better encapsulation of uc-related actions.

Note: I've introduced uc_to_gt instead of uc_to_i915 because the aim is
to move everything to be gt-focused in the medium term, so we would've
had to replace it soon anyway.
Signed-off-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Acked-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190713100016.8026-8-chris@chris-wilson.co.ukSigned-off-by: NChris Wilson <chris@chris-wilson.co.uk>

The "misc" terminology doesn't clearly explain what we intend to cover
in this phase. The only thing we used ot do in there apart from FW fetch
was initializing the log workqueue, with the latter being required only in
the very rare case where we enable the log relay. As we no longer create
our own workqueue, piggybacking on the system_highpri_wq instead, we can
rename the function to clarify that they only fetch/release the blobs.

v2: only create log wq when needed (Michal), reword commit msg
accordingly
v3: after rebase the wq is gone, reword commit msg accordingly
Signed-off-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190713100016.8026-2-chris@chris-wilson.co.ukSigned-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Having taken the first step in encapsulating the functionality by moving
the related files under gt/, the next step is to start encapsulating by
passing around the relevant structs rather than the global
drm_i915_private. In this step, we pass intel_gt to intel_reset.c
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190712192953.9187-1-chris@chris-wilson.co.uk

Similar to the "_release" case, consistently replace mixed
"_cleanup"/"_fini"/"_fini_hw" components found in names of functions
called from i915_driver_remove() with "_remove" or "_driver_remove"
suffixes for better code readability.
Signed-off-by: NJanusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190712112429.740-6-janusz.krzysztofik@linux.intel.com

Replace mixed "_fini"/"_cleanup"/"_cleanup_hw" suffixes found in names
of functions called from i915_driver_release() with "_release" suffix
consistently.  This provides better code readability, especially
helpful when trying to work out which phase the code is in.

Functions names starting with "i915_driver_", i.e., those defined in
drivers/gpu/dri/i915/i915_drv.c, just have their "cleanup" or "fini"
parts of their names replaced with the "_release" suffix, while names
of functions coming from other source files have been suffixed with
"_driver_release" to avoid ambiguity with other possible .release entry
points.

v2: early_probe pairs better with late_release (Chris)
v3: fix typo in commit message (Joonas)
Suggested-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJanusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190712112429.740-5-janusz.krzysztofik@linux.intel.com

Use the "_probe" nomenclature not only in i915_driver_probe() helper
name but also in other related function / variable names for
consistency.  Only the userspace exposed name of a related module
parameter is left untouched.
Signed-off-by: NJanusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190712112429.740-4-janusz.krzysztofik@linux.intel.com

As we have dropped the final reference to the object, we do not need to
wait until after the rcu grace period to drop its pages. We still require
struct_mutex to completely unbind the object to release the pages, so we
still need a free-worker to manage that from process context. By
scheduling the release of pages before waiting for the rcu should mean
that we are not trapping those pages from beyond the reach of the
shrinker.

v2: Pass along the request to skip if the vma is busy to the underlying
unbind routine, to avoid checking the reservation underneath the
i915->mm.obj_lock which may be used from inside irq context.

v3: Flip the bit for unbinding while active, for later convenience.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=111035
Fixes: a93615f9 ("drm/i915: Throw away the active object retirement complexity")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190703091726.11690-6-chris@chris-wilson.co.uk

Since the reset path wants to recover the engines itself, it only wants
to reinitialise the hardware using i915_gem_init_hw(). Pull the call to
intel_engines_resume() to the module init/resume path so we can avoid it
during reset.

Fixes: 79ffac85 ("drm/i915: Invert the GEM wakeref hierarchy")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190626154549.10066-3-chris@chris-wilson.co.uk

Switch from passing the i915 container to newly named struct intel_gt.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190625130128.11009-2-chris@chris-wilson.co.uk

Since the anonymous i915_gt became struct intel_gt and encloses
struct i915_gt_timelines, rename i915_gt_timelines to intel_gt_timelines
to match its parentage.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190621131640.28864-1-chris@chris-wilson.co.uk

Scratch vma lives under gt but the API used to work on i915. Make this
consistent by renaming the function to intel_gt_scratch_offset and make
it take struct intel_gt.

v2:
 * Move to intel_gt. (Chris)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190621070811.7006-33-tvrtko.ursulin@linux.intel.com

Move all timeline code under gt and rename to intel_gt prefix.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Suggested-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190621070811.7006-32-tvrtko.ursulin@linux.intel.com

Continuing on the theme of better logical organization of our code, make
the first step towards making the ggtt code better isolated from wider
struct drm_i915_private.

v2:
 * Bring the ickle onion unwind back. (Chris)
 * Rename to i915_init_ggtt. (Chris)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190621070811.7006-27-tvrtko.ursulin@linux.intel.com

This aligns better with the rest of restructuring.

v2:
 * Move call out of line. (Chris)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Suggested-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190621070811.7006-24-tvrtko.ursulin@linux.intel.com

Having introduced struct intel_gt (named the anonymous structure in i915)
we can start using it to compartmentalize our code better. It makes more
sense logically to have the code internally like this and it will also
help with future split between gt and display in i915.

v2:
 * Keep ggtt flush before fb obj flush. (Chris)

v3:
 * Fix refactoring fail.
 * Always flush ggtt writes. (Chris)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190621070811.7006-23-tvrtko.ursulin@linux.intel.com

More legacy mmio accessor removal. We pass in intel_gt explicitly allowing
code to use new intel_uncore_read/write helpers.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190621070811.7006-17-tvrtko.ursulin@linux.intel.com

Since this part still operates on i915 and not intel_gt, move it to the
common (top-level) function.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190621070811.7006-16-tvrtko.ursulin@linux.intel.com

More removal of implicit dev_priv from using old mmio accessors.

Actually the top level function remains but is split into a part which
writes to i915 and part which operates on intel_gt in order to initialize
the hardware.

GuC and engines are the only odd ones out remaining.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190621070811.7006-15-tvrtko.ursulin@linux.intel.com

More removal of implicit dev_priv from using old mmio accessors.

v2:
 * Rebase for uncore_to_i915 removal.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190621070811.7006-13-tvrtko.ursulin@linux.intel.com

More removal of implicit dev_priv from using old mmio accessors.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190621070811.7006-12-tvrtko.ursulin@linux.intel.com

More conversion of i915_gem_init_hw to uncore.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190621070811.7006-10-tvrtko.ursulin@linux.intel.com

More removal of implicit dev_priv from using old mmio accessors.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190621070811.7006-9-tvrtko.ursulin@linux.intel.com

Start using the newly introduced struct intel_gt to fuse together correct
logical init flow with uncore for more removal of implicit dev_priv in
mmio access.

v2:
 * Move code to i915_gem_fence_reg. (Chris)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190621070811.7006-7-tvrtko.ursulin@linux.intel.com