drm/i915/gt: Another tweak for flushing the tasklets

tasklet_kill() ensures that we _yield_ the processor until a remote
tasklet is completed. However, this leads to a starvation condition as
being at the bottom of the scheduler's runqueue means that anything else
is able to run, including all hogs keeping the tasklet occupied.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201220134858.10510-1-chris@chris-wilson.co.uk

drm/i915: Check for rq->hwsp validity after acquiring RCU lock

Since we allow removing the timeline map at runtime, there is a risk
that rq->hwsp points into a stale page. To control that risk, we hold
the RCU read lock while reading *rq->hwsp, but we missed a couple of
important barriers. First, the unpinning / removal of the timeline map
must be after all RCU readers into that map are complete, i.e. after an
rcu barrier (in this case courtesy of call_rcu()). Secondly, we must
make sure that the rq->hwsp we are about to dereference under the RCU
lock is valid. In this case, we make the rq->hwsp pointer safe during
i915_request_retire() and so we know that rq->hwsp may become invalid
only after the request has been signaled. Therefore is the request is
not yet signaled when we acquire rq->hwsp under the RCU, we know that
rq->hwsp will remain valid for the duration of the RCU read lock.

This is a very small window that may lead to either considering the
request not completed (causing a delay until the request is checked
again, any wait for the request is not affected) or dereferencing an
invalid pointer.

Fixes: 3adac4689f58 ("drm/i915: Introduce concept of per-timeline (context) HWSP")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: <stable@vger.kernel.org> # v5.1+
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201218122421.18344-1-chris@chris-wilson.co.uk

drm/i915/tgl: Add bound checks and simplify TGL REVID macros

Add bound checks for TGL REV ID array. Since, there might
be a possibility of using older kernels on latest platform
revisions, resulting in out of bounds access for rev ID array.
In this scenario, use the latest rev ID available and apply
those WAs.

Also, modify GT macros for TGL rev ID to reuse tgl_revids_get().

Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Aditya Swarup <aditya.swarup@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201203072359.156682-2-aditya.swarup@intel.com

drm/i915/tgl: Fix REVID macros for TGL to fetch correct stepping

Fix TGL REVID macros to fetch correct display/gt stepping based
on SOC rev id from INTEL_REVID() macro. Previously, we were just
returning the first element of the revid array instead of using
the correct index based on SOC rev id.

Fixes: c33298cb34f5 ("drm/i915/tgl: Fix stepping WA matching")
Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Aditya Swarup <aditya.swarup@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201203072359.156682-1-aditya.swarup@intel.com

drm/i915/gt: Track the overall awake/busy time

Since we wake the GT up before executing a request, and go to sleep as
soon as it is retired, the GT wake time not only represents how long the
device is powered up, but also provides a summary, albeit an overestimate,
of the device runtime (i.e. the rc0 time to compare against rc6 time).

v2: s/busy/awake/
v3: software-gt-awake-time and I915_PMU_SOFTWARE_GT_AWAKE_TIME

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201215154456.13954-1-chris@chris-wilson.co.uk

drm/i915/gt: Drain the breadcrumbs just once

Matthew Brost pointed out that the while-loop on a shared breadcrumb was
inherently fraught with danger as it competed with the other users of
the breadcrumbs. However, in order to completely drain the re-arming irq
worker, the while-loop is a necessity, despite my optimism that we could
force cancellation with a couple of irq_work invocations.

Given that we can't merely drop the while-loop, use an activity counter on
the breadcrumbs to detect when we are parking the breadcrumbs for the
last time.

Based on a patch by Matthew Brost.

Reported-by: Matthew Brost <matthew.brost@intel.com>
Suggested-by: Matthew Brost <matthew.brost@intel.com>
Fixes: 9d5612ca165a ("drm/i915/gt: Defer enabling the breadcrumb interrupt to after submission")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201217091524.10258-1-chris@chris-wilson.co.uk

drm/i915: Encode fence specific waitqueue behaviour into the wait.flags

Use the wait_queue_entry.flags to denote the special fence behaviour
(flattening continuations along fence chains, and for propagating
errors) rather than trying to detect ordinary waiters by their
functions.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201216165850.25030-1-chris@chris-wilson.co.uk

drm/i915/gt: Move gen8 CS emitters into gen8_engine_cs.h

Reduce the pollution of intel_engine.h by moving gen8_emit_pipe_control
and friends to gen8_engine_cs.h

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201216135452.6063-1-chris@chris-wilson.co.uk

drm/i915/gem: Drop free_work for GEM contexts

The free_list and worker was introduced in commit 5f09a9c8ab6b ("drm/i915:
Allow contexts to be unreferenced locklessly"), but subsequently made
redundant by the removal of the last sleeping lock in commit 2935ed5339c4
("drm/i915: Remove logical HW ID"). As we can now free the GEM context
immediately from any context, remove the deferral of the free_list

v2: Lift removing the context from the global list into close().

Suggested-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201215152138.8158-1-chris@chris-wilson.co.uk

drm/i915: Fix mismatch between misplaced vma check and vma insert

When inserting a VMA, we restrict the placement to the low 4G unless the
caller opts into using the full range. This was done to allow usersapce
the opportunity to transition slowly from a 32b address space, and to
avoid breaking inherent 32b assumptions of some commands.

However, for insert we limited ourselves to 4G-4K, but on verification
we allowed the full 4G. This causes some attempts to bind a new buffer
to sporadically fail with -ENOSPC, but at other times be bound
successfully.

commit 48ea1e32c39d ("drm/i915/gen9: Set PIN_ZONE_4G end to 4GB - 1
page") suggests that there is a genuine problem with stateless addressing
that cannot utilize the last page in 4G and so we purposefully excluded
it. This means that the quick pin pass may cause us to utilize a buggy
placement.

Reported-by: CQ Tang <cq.tang@intel.com>
Testcase: igt/gem_exec_params/larger-than-life-batch
Fixes: 48ea1e32c39d ("drm/i915/gen9: Set PIN_ZONE_4G end to 4GB - 1 page")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: CQ Tang <cq.tang@intel.com>
Reviewed-by: CQ Tang <cq.tang@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Cc: <stable@vger.kernel.org> # v4.5+
Link: https://patchwork.freedesktop.org/patch/msgid/20201216092951.7124-1-chris@chris-wilson.co.uk

doc: Fix build of documentation after i915 file rename

Commit 70a2b431c364 ("drm/i915/gt: Rename lrc.c to
execlists_submission.c") renamed intel_lrc.c to
intel_execlists_submission.c but forgot to update i915.rst.

Fixes: 70a2b431c364 ("drm/i915/gt: Rename lrc.c to execlists_submission.c")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201214185440.243537-1-jose.souza@intel.com

drm/i915/pmu: Remove !CONFIG_PM code

Chris spotted that since 16ffe73c186b ("drm/i915/pmu: Use GT parked for
estimating RC6 while asleep") we don't rely on runtime pm internals when
estimating RC6 while asleep. We can remove the ifdef code to simplify and
at the same time wake up the device less when querying RC6 if CONFIG_PM is
not compiled in.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
References: 16ffe73c186b ("drm/i915/pmu: Use GT parked for estimating RC6 while asleep")
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201214094349.3563876-3-tvrtko.ursulin@linux.intel.com

drm/i915/pmu: Use raw clock for rc6 estimation

RC6 is a hardware counter and as such estimating it using the raw clock
during runtime suspend is more appropriate.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
References: 34f439278cef ("perf: Add per event clockid support")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201214094349.3563876-2-tvrtko.ursulin@linux.intel.com

drm/i915/pmu: Don't grab wakeref when enabling events

Chris found a CI report which points out calling intel_runtime_pm_get from
inside i915_pmu_enable hook is not allowed since it can be invoked from
hard irq context. This is something we knew but forgot, so lets fix it
once again.

We do this by syncing the internal book keeping with hardware rc6 counter
on driver load.

v2:
 * Always sync on parking and fully sync on init.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Fixes: f4e9894b6952 ("drm/i915/pmu: Correct the rc6 offset upon enabling")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201214094349.3563876-1-tvrtko.ursulin@linux.intel.com

drm/i915/gt: Wean workaround selftests off GEM context

The workarounds are tied to the GT and we should derive the tests local
to the GT.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201210080240.24529-2-chris@chris-wilson.co.uk

drm/i915/gt: Mark legacy ring context as lost

When we reset the legacy ring context, due to potential corruption over
suspend/resume, remove the valid bit so that we avoid loading garbage.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201210080240.24529-1-chris@chris-wilson.co.uk

drm/i915: Correct location of Wa_1408615072

The above workaround was added as an engine workaround not a GT
workaround. Moved it to the correct location.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201210170615.3107266-1-lucas.demarchi@intel.com

drm/i915: split gen8+ flush and bb_start emission functions

These functions are independent from the backend used and can therefore
be split out of the exelists submission file, so they can be re-used by
the upcoming GuC submission backend.

Based on a patch by Chris Wilson.

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201209233618.4287-3-chris@chris-wilson.co.uk
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drm/i915/gt: Rename lrc.c to execlists_submission.c

We want to separate the utility functions for controlling the logical
ring context from the execlists submission mechanism (which is an
overgrown scheduler).

This is similar to Daniele's work to split up the files, but being
selfish I wanted to base it after my own changes to intel_lrc.c petered
out.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201209233618.4287-2-chris@chris-wilson.co.uk

drm/i915/gt: Move move context layout registers and offsets to lrc_reg.h

Cleanup intel_lrc.h by moving some of the residual common register
definitions into intel_lrc_reg.h, prior to rebranding and splitting off
the submission backends.

v2: keep the SCHEDULE enum in the old file, since it is specific to the
gvt usage of the execlists submission backend (John)

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com> #v2
Cc: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201209233618.4287-1-chris@chris-wilson.co.uk

drm/i915/gt: Remove uninterruptible parameter from intel_gt_wait_for_idle

Now that the only user of the uninterruptible wait was eliminated,
remove the support.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201209164008.5487-3-chris@chris-wilson.co.uk

drm/i915: Sleep around performing iommu unmaps on Tigerlake

Tigerlake is plagued by spontaneous DMAR faults [reason 7, next page
table ptr is invalid] which lead to GPU hangs. These faults occur when
an iommu map is immediately reused. Adding further clflushes and
barriers around either the GTT PTE or iommu PTE updates do not prevent
the faults. So far the only effect has been from inducing a delay
between reuse of the iommu on the GPU, and applying the delay at the
iommu map allows for the smallest stable delay.

Note that such a delay is hideous and clearly does not fix the root cause,
and so should only be a bandaid until a complete solution is found. The
delay was determined by running igt/gem_exec_fence/parallel in a loop for
a few hours (unpatched MTBF is about 10s).

We have also seen such DMAR fault [reason 7] errors on other platforms,
notably gen9-gen11, but so far it has only been trivially and
consistently reproduced on Tigerlake.

v2: Leave a tell-tale to know when we apply the vt'd quirk, and as a
reminder to remove it again. Hopefully.

Testcase: igt/gem_exec_fence/parallel
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Acked-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201209164008.5487-2-chris@chris-wilson.co.uk

drm/i915: Remove livelock from "do_idle_maps" vtd w/a

A call to wait for the GT to idle from inside the put_pages fallback is
prone to cause an uninterruptible livelock. As it does not provide
adequate serialisation with new requests, simply fallback to a trivial
sleep.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201209164008.5487-1-chris@chris-wilson.co.uk

drm/i915/gt: document masked registers

Document what a masked register is according to bspec so we avoid
developers using the wrong functions to implement WAs.

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201209045246.2905675-3-lucas.demarchi@intel.com

drm/i915/gt: rename wa_write_masked_or()

The use of "masked" in this function is due to its history. Once upon a
time it received a mask and a value as parameter. Since
commit eeec73f8a4a4 ("drm/i915/gt: Skip rmw for masked registers")
that is not true anymore and now there is a clear and a set parameter.
Depending on the case, that can still be thought as a mask and value,
but there are some subtle differences: what we clear doesn't need to be
the same bits we are setting, particularly when we are using masked
registers.

The fact that we also have "masked registers", i.e. registers whose mask
is stored in the upper 16 bits of the register, makes it even more
confusing, because "masked" in wa_write_masked_or() has little to do
with masked registers, but rather refers to the old mask parameter the
function received (that can also, but not exclusively, be used to write
to masked register).

Avoid the ambiguity and misnomer by renaming it to something else,
hopefully less confusing: wa_write_clr_set(), to designate that we are
doing both clr and set operations in the register.

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201209045246.2905675-2-lucas.demarchi@intel.com

drm/i915/gt: stop ignoring read with wa_masked_field_set

When using masked registers, there is nothing to clear since a masked
register has the mask in the upper 16b: we can just write to the
location we want and use the mask to control what bits we are writing
to.

However that doesn't mean we don't want to read back the register and
check the value actually matched what we wanted to write, i.e. that
the WA stick. That should be an explicit opt-out for registers that are
either write-only or that are affected by hardware misbehavior.

Moreover both wa_masked_en() and wa_masked_dis() check the WA stick, so
skipping the check just because the field is more than 1 bit is
surprising and error-prone.

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201209045246.2905675-1-lucas.demarchi@intel.com

drm/i915/gem: Drop false !i915_vma_is_closed assertion

Closed vma are protected by the GT wakeref held as we lookup the vma, so
we know that the vma will not be freed as we process it for the execbuf.
Instead we expect to catch the closed status of the context, and simply
allow the close-race on an individual vma to be washed away.

Longer term, the GT wakeref protection will be removed by explicit
vma.kref tracking.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/2245
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201207193824.18114-1-chris@chris-wilson.co.uk

drm/i915/selftests: Improve error reporting for igt_mock_max_segment

When we fail to find a single block large enough to require splitting,
report the largest block we did find.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Ramalingam C <ramalingam.c@intel.com>
Reviewed-by: Ramalingam C <ramalingam.c@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201207130346.11849-1-chris@chris-wilson.co.uk

drm/i915: fix size_t greater or equal to zero comparison

Currently the check that the unsigned size_t variable i is >= 0
is always true because the unsigned variable will never be negative,
causing the loop to run forever.  Fix this by changing the
pre-decrement check to a zero check on i followed by a decrement of i.

Addresses-Coverity: ("Unsigned compared against 0")
Fixes: bfed6708d6c9 ("drm/i915: use vmap in shmem_pin_map")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201002170354.94627-1-colin.king@canonical.com

drm/i915: remove WA_SET_FIELD_MASKED()

Remove the last macro and implement it as a function like the rest of
the operations that don't assume there is a `wal` list, but rather
receive it as argument.

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201205092542.2325477-4-lucas.demarchi@intel.com

drm/i915: remove WA_CLR_BIT_MASKED()

Just ommitting the list it's operating on doesn't save much typing
and adds another way to do the same thing. Just replace it with
wa_masked_dis().

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201205092542.2325477-3-lucas.demarchi@intel.com

drm/i915: remove WA_SET_BIT_MASKED()

Just ommitting the list it's operating on doesn't save much typing and
adds another way to do the same thing. Just replace it with
wa_masked_en().

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201205092542.2325477-2-lucas.demarchi@intel.com

drm/i915/dg1: Implement WA_16011163337

Set GS Timer to 224 to prevent a HS/DS hang.

Bspec: 53508

v2: reword commit message and add comment explaining why read
verification is ignored (Chris)

Cc: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Swathi Dhanavanthri <swathi.dhanavanthri@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201205092542.2325477-1-lucas.demarchi@intel.com

drm/i915/gt: Clear the execlists timers upon reset

Across a reset, we stop the engine but not the timers. This leaves a
window where the timers have inconsistent state with the engine, but
should only result in a spurious timeout. As we cancel the outstanding
events, also cancel their timers.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201204151234.19729-4-chris@chris-wilson.co.uk

drm/i915/gt: Include reset failures in the trace

The GT and engine reset failures are completely invisible when looking at
a trace for a bug, but are vital to understanding the incomplete flow.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201204151234.19729-3-chris@chris-wilson.co.uk

drm/i915/gt: Cancel the preemption timeout on responding to it

We currently presume that the engine reset is successful, cancelling the
expired preemption timer in the process. However, engine resets can
fail, leaving the timeout still pending and we will then respond to the
timeout again next time the tasklet fires. What we want is for the
failed engine reset to be promoted to a full device reset, which is
kicked by the heartbeat once the engine stops processing events.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/1168
Fixes: 3a7a92aba8fb ("drm/i915/execlists: Force preemption")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: <stable@vger.kernel.org> # v5.5+
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201204151234.19729-2-chris@chris-wilson.co.uk

drm/i915/gt: Ignore repeated attempts to suspend request flow across reset

Before reseting the engine, we suspend the execution of the guilty
request, so that we can continue execution with a new context while we
slowly compress the captured error state for the guilty context. However,
if the reset fails, we will promptly attempt to reset the same request
again, and discover the ongoing capture. Ignore the second attempt to
suspend and capture the same request.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/1168
Fixes: 32ff621fd744 ("drm/i915/gt: Allow temporary suspension of inflight requests")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: <stable@vger.kernel.org> # v5.7+
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201204151234.19729-1-chris@chris-wilson.co.uk

drm/i915/gem: Propagate error from cancelled submit due to context closure

In the course of discovering and closing many races with context closure
and execbuf submission, since commit 61231f6bd056 ("drm/i915/gem: Check
that the context wasn't closed during setup") we started checking that
the context was not closed by another userspace thread during the execbuf
ioctl. In doing so we cancelled the inflight request (by telling it to be
skipped), but kept reporting success since we do submit a request, albeit
one that doesn't execute. As the error is known before we return from the
ioctl, we can report the error we detect immediately, rather than leave
it on the fence status. With the immediate propagation of the error, it
is easier for userspace to handle.

Fixes: 61231f6bd056 ("drm/i915/gem: Check that the context wasn't closed during setup")
Testcase: igt/gem_ctx_exec/basic-close-race
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: <stable@vger.kernel.org> # v5.7+
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201203103432.31526-1-chris@chris-wilson.co.uk

drm/i915/gem: Check the correct variable in selftest

There is a copy and paste bug in this code.  It's supposed to check
"obj2" instead of checking "obj" a second time.

Fixes: 80f0b679d6f0 ("drm/i915: Add an implementation for i915_gem_ww_ctx locking, v2.")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/8ilneOcJAjwqU4t@mwand

Revert "drm/i915/lmem: Limit block size to 4G"

Mixing I915_ALLOC_CONTIGUOUS and I915_ALLOC_MAX_SEGMENT_SIZE fared
badly. The two directives conflict, with the contiguous request setting
the min_order to the full size of the object, and the max-segment-size
setting the max_order to the limit of the DMA mapper. This results in a
situation where max_order < min_order, causing our sanity checks to
fail.

Instead of limiting the buddy block size, in the previous patch we split
the oversized buddy into multiple scatterlist elements.

Fixes: d2cf0125d4a1 ("drm/i915/lmem: Limit block size to 4G")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201202173444.14903-2-chris@chris-wilson.co.uk

drm/i915/gem: Limit lmem scatterlist elements to UINT_MAX

Adhere to the i915_sg_max_segment() limit on the lengths of individual
scatterlist elements, and in doing so split up very large chunks of lmem
into manageable pieces for the dma-mapping backend.

Reported-by: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota@intel.com>
Suggested-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201202173444.14903-1-chris@chris-wilson.co.uk

drm/i915/selftests: Tidy prng constructor for client blits

Since we only initialise the prng once within the scope of the selftest,
we can use the default initialiser.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201202130406.18461-1-chris@chris-wilson.co.uk

drm/i915/pmu: Deprecate I915_PMU_LAST and optimize state tracking

Adding any kinds of "last" abi markers is usually a mistake which I
repeated when implementing the PMU because it felt convenient at the time.

This patch marks I915_PMU_LAST as deprecated and stops the internal
implementation using it for sizing the event status bitmask and array.

New way of sizing the fields is a bit less elegant, but it omits reserving
slots for tracking events we are not interested in, and as such saves some
runtime space. Adding sampling events is likely to be a special event and
the new plumbing needed will be easily detected in testing. Existing
asserts against the bitfield and array sizes are keeping the code safe.

First event which gets the new treatment in this new scheme are the
interrupts - which neither needs any tracking in i915 pmu nor needs
waking up the GPU to read it.

v2:
 * Streamline helper names. (Chris)

v3:
 * Comment which events need tracking. (Chris)

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201201131757.206367-1-tvrtko.ursulin@linux.intel.com

drm/i915/gem: Report error for vmap() failure

Convert the NULL pointer from a failed vmap() to ERR_PTR(-ENOMEM) for
propagation.

<1> [269.830447] BUG: kernel NULL pointer dereference, address: 0000000000000000
<1> [269.830455] #PF: supervisor write access in kernel mode
<1> [269.830457] #PF: error_code(0x0002) - not-present page
<6> [269.830459] PGD 0 P4D 0
<4> [269.830465] Oops: 0002 [#1] PREEMPT SMP PTI
<4> [269.830469] CPU: 3 PID: 5789 Comm: i915_selftest Tainted: G     U            5.10.0-rc6-CI-CI_DRM_9412+ #1
<4> [269.830472] Hardware name: Intel Corp. Geminilake/GLK RVP2 LP4SD (07), BIOS GELKRVPA.X64.0062.B30.1708222146 08/22/2017
<4> [269.830636] RIP: 0010:igt_client_fill+0x1b9/0x5f0 [i915]
<4> [269.830640] Code: e8 0c 32 02 00 48 89 c5 48 3d 00 f0 ff ff 0f 87 e9 02 00 00 48 8b 8b 78 06 00 00 44 89 f0 48 89 ef 35 af be ad de 48 c1 e9 02 <f3> ab 0f b6 83 80 03 00 00 89 c2 c0 ea 03 83 e2 02 75 09 83 c8 20
<4> [269.830642] RSP: 0018:ffffc900007a79e8 EFLAGS: 00010206
<4> [269.830645] RAX: 00000000df0bf37b RBX: ffff88811d8af3c0 RCX: 00000000010afc00
<4> [269.830647] RDX: 0000000000000000 RSI: ffffffff822f2b17 RDI: 0000000000000000
<4> [269.830648] RBP: 0000000000000000 R08: ffff888111c80930 R09: 00000000fffffffe
<4> [269.830650] R10: 0000000000000000 R11: 00000000ffbc70e4 R12: ffff88811090f700
<4> [269.830652] R13: ffff88810df60180 R14: 0000000001a64dd4 R15: 0000000000000000
<4> [269.830655] FS:  00007f137b07de40(0000) GS:ffff88817b980000(0000) knlGS:0000000000000000
<4> [269.830657] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4> [269.830659] CR2: 0000000000000000 CR3: 0000000115984000 CR4: 0000000000350ee0
<4> [269.830661] Call Trace:
<4> [269.830780]  __i915_subtests.cold.7+0x42/0x92 [i915]
<4> [269.830886]  ? __i915_nop_teardown+0x10/0x10 [i915]
<4> [269.830989]  ? __i915_live_setup+0x30/0x30 [i915]
<4> [269.831104]  __run_selftests.part.3+0xf7/0x14c [i915]
<4> [269.831939]  i915_live_selftests.cold.5+0x1f/0x47 [i915]
<4> [269.832027]  i915_pci_probe+0x93/0x1d0 [i915]
<4> [269.832037]  ? _raw_spin_unlock_irqrestore+0x2f/0x50
<4> [269.832043]  pci_device_probe+0x9e/0x110
<4> [269.832049]  really_probe+0x1c4/0x430
<4> [269.832053]  driver_probe_device+0xd9/0x140
<4> [269.832056]  device_driver_attach+0x4a/0x50
<4> [269.832059]  __driver_attach+0x83/0x140
<4> [269.832062]  ? device_driver_attach+0x50/0x50
<4> [269.832064]  ? device_driver_attach+0x50/0x50
<4> [269.832067]  bus_for_each_dev+0x75/0xc0
<4> [269.832070]  bus_add_driver+0x14b/0x1f0
<4> [269.832073]  driver_register+0x66/0xb0
<4> [269.832160]  i915_init+0x70/0x87 [i915]
<4> [269.832164]  ? 0xffffffffa05e3000
<4> [269.832168]  do_one_initcall+0x56/0x2e0
<4> [269.832174]  ? kmem_cache_alloc_trace+0x6a4/0x770
<4> [269.832180]  do_init_module+0x55/0x200
<4> [269.832184]  load_module+0x22a2/0x2480
<4> [269.832191]  ? __do_sys_finit_module+0xad/0x110
<4> [269.832194]  __do_sys_finit_module+0xad/0x110
<4> [269.832199]  do_syscall_64+0x33/0x80
<4> [269.832202]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
<4> [269.832204] RIP: 0033:0x7f137a718839
<4> [269.832208] Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 1f f6 2c 00 f7 d8 64 89 01 48
<4> [269.832210] RSP: 002b:00007ffc4267d308 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
<4> [269.832214] RAX: ffffffffffffffda RBX: 000056288b88f0d0 RCX: 00007f137a718839
<4> [269.832216] RDX: 0000000000000000 RSI: 000056288b895850 RDI: 0000000000000007
<4> [269.832218] RBP: 000056288b895850 R08: 312d3d7374736574 R09: 000056288b88c020
<4> [269.832220] R10: 00007ffc4267d450 R11: 0000000000000246 R12: 0000000000000000
<4> [269.832222] R13: 000056288b8877a0 R14: 0000000000000020 R15: 0000000000000045
<4> [269.832226] Modules linked in: i915(+) vgem mei_hdcp snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio x86_pkg_temp_thermal coretemp crct10dif_pclmul crc32_pclmul ghash_clmulni_intel cdc_ether usbnet snd_intel_dspcfg mii snd_hda_codec snd_hwdep snd_hda_core r8169 snd_pcm realtek mei_me mei prime_numbers intel_lpss_pci i2c_hid pinctrl_geminilake [last unloaded: i915]
<4> [269.832264] CR2: 0000000000000000

Fixes: cb2ce93e5b05 ("drm/i915/gem: Differentiate oom failures from invalid map types")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201201215441.31900-1-chris@chris-wilson.co.uk

drm/i915/tgl, rkl, dg1: Apply WA_1406941453 to TGL, RKL and DG1

This workaround is applicable only for tgl,rkl and dg1.

Bspec: 52890, 53273, 53508.

Signed-off-by: Swathi Dhanavanthri <swathi.dhanavanthri@intel.com>
Reviewed-by: Clint Taylor <Clinton.A.Taylor@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201201175735.1377372-1-lucas.demarchi@intel.com

drm/i915/gem: Differentiate oom failures from invalid map types

After a cursory check on the parameters to i915_gem_object_pin_map(),
where we return a precise error, if the backend rejects the mapping we
always return PTR_ERR(-ENOMEM). Let us also return a more precise error
here so we can differentiate between running out of memory and
programming errors (or situations where we may be trying different paths
and looking for an error from an unsupported map).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201127195334.13134-1-chris@chris-wilson.co.uk

drm/i915/lmem: Limit block size to 4G

Block sizes are only limited by the largest power-of-two that will fit
in the region size, but to construct an object we also require feeding
it into an sg list, where the upper limit of the sg entry is at most
UINT_MAX. Therefore to prevent issues with allocating blocks that are
too large, add the flag I915_ALLOC_MAX_SEGMENT_SIZE which should limit
block sizes to the i915_sg_segment_size().

v2: (matt)
  - query the max segment.
  - prefer flag to limit block size to 4G, since it's best not to assume
    the user will feed the blocks into an sg list.
  - simple selftest so we don't have to guess.

Cc: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: CQ Tang <cq.tang@intel.com>
Signed-off-by: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201130134721.54457-1-matthew.auld@intel.com

drm/i915/selftest: assert we get 2M GTT pages

For the LMEM case if we have suitable alignment and 2M physical pages we
should always get 2M GTT pages within the constraints of the hugepages
selftest. If we don't then something might be wrong in our construction
of the backing pages.

References: 330b7d33056b ("drm/i915/region: fix order when adding blocks")
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201130141809.65330-2-matthew.auld@intel.com

drm/i915/selftest: also consider non-contiguous objects

In igt_ppgtt_sanity_check we should also exercise the non-contiguous
option for LMEM, since this will give us slightly different sg layouts
and alignment.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201130141809.65330-1-matthew.auld@intel.com

drm/i915/gt: Limit frequency drop to RPe on parking

We treat idling the GT (intel_rps_park) as a downclock event, and reduce
the frequency we intend to restart the GT with. Since the two workloads
are likely related (e.g. a compositor rendering every 16ms), we want to
carry the frequency and load information from across the idling.
However, we do also need to update the frequencies so that workloads
that run for less than 1ms are autotuned by RPS (otherwise we leave
compositors running at max clocks, draining excess power). Conversely,
if we try to run too slowly, the next workload has to run longer. Since
there is a hysteresis in the power graph, below a certain frequency
running a short workload for longer consumes more energy than running it
slightly higher for less time. The exact balance point is unknown
beforehand, but measurements with 30fps media playback indicate that RPe
is a better choice.

Reported-by: Edward Baker <edward.baker@intel.com>
Tested-by: Edward Baker <edward.baker@intel.com>
Fixes: 043cd2d14ede ("drm/i915/gt: Leave rps->cur_freq on unpark")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Edward Baker <edward.baker@intel.com>
Cc: Andi Shyti <andi.shyti@intel.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: <stable@vger.kernel.org> # v5.8+
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201124183521.28623-1-chris@chris-wilson.co.uk

drm/i915/perf: replace idr_init() by idr_init_base()

idr_init() uses base 0 which is an invalid identifier. The new function
idr_init_base allows IDR to set the ID lookup from base 1. This avoids
all lookups that otherwise starts from 0 since 0 is always unused.

References: commit 6ce711f27500 ("idr: Make 1-based IDRs more efficient")

Signed-off-by: Deepak R Varma <mh12gx2825@gmail.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201104150339.GA68663@localhost

drm/i915/gt: Retain default context state across shrinking

As we use a shmemfs file to hold the context state, when not in use it
may be swapped out, such as across suspend. Since we wrote into the
shmemfs without marking the pages as dirty, the contents may be dropped
instead of being written back to swap. On re-using the shmemfs file,
such as creating a new context after resume, the contents of that file
were likely garbage and so the new context could then hang the GPU.

Simply mark the page as being written when copying into the shmemfs
file, and it the new contents will be retained across swapout.

Fixes: be1cb55a07bf ("drm/i915/gt: Keep a no-frills swappable copy of the default context state")
Cc: Sudeep Dutt <sudeep.dutt@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Ramalingam C <ramalingam.c@intel.com>
Signed-off-by: CQ Tang <cq.tang@intel.com>
Signed-off-by: Venkata Ramana Nayana <venkata.ramana.nayana@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: <stable@vger.kernel.org> # v5.8+
Link: https://patchwork.freedesktop.org/patch/msgid/20201127120718.454037-161-matthew.auld@intel.com

drm/i915/gt: Declare gen9 has 64 mocs entries!

We checked the table size against a hardcoded number of entries, and
that number was excluding the special mocs registers at the end.

Fixes: 977933b5da7c ("drm/i915/gt: Program mocs:63 for cache eviction on gen9")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: <stable@vger.kernel.org> # v4.3+
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201127102540.13117-1-chris@chris-wilson.co.uk

drm/i915/gt: Move the breadcrumb to the signaler if completed upon cancel

If while we are cancelling the breadcrumb signaling, we find that the
request is already completed, move it to the irq signaler and let it be
signaled.

v2: Tweak reference counting so that we only acquire a new reference on
adding to a signal list, as opposed to a hidden i915_request_put of the
caller's reference.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201126140407.31952-5-chris@chris-wilson.co.uk

drm/i915/gt: Split the breadcrumb spinlock between global and contexts

As we funnel more and more contexts into the breadcrumbs on an engine,
the hold time of b->irq_lock grows. As we may then contend with the
b->irq_lock during request submission, this increases the burden upon
the engine->active.lock and so directly impacts both our execution
latency and client latency. If we split the b->irq_lock by introducing a
per-context spinlock to manage the signalers within a context, we then
only need the b->irq_lock for enabling/disabling the interrupt and can
avoid taking the lock for walking the list of contexts within the signal
worker. Even with the current setup, this greatly reduces the number of
times we have to take and fight for b->irq_lock.

Furthermore, this closes the race between enabling the signaling context
while it is in the process of being signaled and removed:

<4>[  416.208555] list_add corruption. prev->next should be next (ffff8881951d5910), but was dead000000000100. (prev=ffff8882781bb870).
<4>[  416.208573] WARNING: CPU: 7 PID: 0 at lib/list_debug.c:28 __list_add_valid+0x4d/0x70
<4>[  416.208575] Modules linked in: i915(+) vgem snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio mei_hdcp x86_pkg_temp_thermal coretemp ax88179_178a usbnet mii crct10dif_pclmul snd_intel_dspcfg crc32_pclmul snd_hda_codec snd_hwdep ghash_clmulni_intel snd_hda_core e1000e snd_pcm ptp pps_core mei_me mei prime_numbers intel_lpss_pci [last unloaded: i915]
<4>[  416.208611] CPU: 7 PID: 0 Comm: swapper/7 Tainted: G     U            5.8.0-CI-CI_DRM_8852+ #1
<4>[  416.208614] Hardware name: Intel Corporation Ice Lake Client Platform/IceLake Y LPDDR4x T4 RVP TLC, BIOS ICLSFWR1.R00.3212.A00.1905212112 05/21/2019
<4>[  416.208627] RIP: 0010:__list_add_valid+0x4d/0x70
<4>[  416.208631] Code: c3 48 89 d1 48 c7 c7 60 18 33 82 48 89 c2 e8 ea e0 b6 ff 0f 0b 31 c0 c3 48 89 c1 4c 89 c6 48 c7 c7 b0 18 33 82 e8 d3 e0 b6 ff <0f> 0b 31 c0 c3 48 89 f2 4c 89 c1 48 89 fe 48 c7 c7 00 19 33 82 e8
<4>[  416.208633] RSP: 0018:ffffc90000280e18 EFLAGS: 00010086
<4>[  416.208636] RAX: 0000000000000000 RBX: ffff888250a44880 RCX: 0000000000000105
<4>[  416.208639] RDX: 0000000000000105 RSI: ffffffff82320c5b RDI: 00000000ffffffff
<4>[  416.208641] RBP: ffff8882781bb870 R08: 0000000000000000 R09: 0000000000000001
<4>[  416.208643] R10: 00000000054d2957 R11: 000000006abbd991 R12: ffff8881951d58c8
<4>[  416.208646] R13: ffff888286073880 R14: ffff888286073848 R15: ffff8881951d5910
<4>[  416.208669] FS:  0000000000000000(0000) GS:ffff88829c180000(0000) knlGS:0000000000000000
<4>[  416.208671] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4>[  416.208673] CR2: 0000556231326c48 CR3: 0000000005610001 CR4: 0000000000760ee0
<4>[  416.208675] PKRU: 55555554
<4>[  416.208677] Call Trace:
<4>[  416.208679]  <IRQ>
<4>[  416.208751]  i915_request_enable_breadcrumb+0x278/0x400 [i915]
<4>[  416.208839]  __i915_request_submit+0xca/0x2a0 [i915]
<4>[  416.208892]  __execlists_submission_tasklet+0x480/0x1830 [i915]
<4>[  416.208942]  execlists_submission_tasklet+0xc4/0x130 [i915]
<4>[  416.208947]  tasklet_action_common.isra.17+0x6c/0x1c0
<4>[  416.208954]  __do_softirq+0xdf/0x498
<4>[  416.208960]  ? handle_fasteoi_irq+0x150/0x150
<4>[  416.208964]  asm_call_on_stack+0xf/0x20
<4>[  416.208966]  </IRQ>
<4>[  416.208969]  do_softirq_own_stack+0xa1/0xc0
<4>[  416.208972]  irq_exit_rcu+0xb5/0xc0
<4>[  416.208976]  common_interrupt+0xf7/0x260
<4>[  416.208980]  asm_common_interrupt+0x1e/0x40
<4>[  416.208985] RIP: 0010:cpuidle_enter_state+0xb6/0x410
<4>[  416.208987] Code: 00 31 ff e8 9c 3e 89 ff 80 7c 24 0b 00 74 12 9c 58 f6 c4 02 0f 85 31 03 00 00 31 ff e8 e3 6c 90 ff e8 fe a4 94 ff fb 45 85 ed <0f> 88 c7 02 00 00 49 63 c5 4c 2b 24 24 48 8d 14 40 48 8d 14 90 48
<4>[  416.208989] RSP: 0018:ffffc90000143e70 EFLAGS: 00000206
<4>[  416.208991] RAX: 0000000000000007 RBX: ffffe8ffffda8070 RCX: 0000000000000000
<4>[  416.208993] RDX: 0000000000000000 RSI: ffffffff8238b4ee RDI: ffffffff8233184f
<4>[  416.208995] RBP: ffffffff826b4e00 R08: 0000000000000000 R09: 0000000000000000
<4>[  416.208997] R10: 0000000000000001 R11: 0000000000000000 R12: 00000060e7f24a8f
<4>[  416.208998] R13: 0000000000000003 R14: 0000000000000003 R15: 0000000000000003
<4>[  416.209012]  cpuidle_enter+0x24/0x40
<4>[  416.209016]  do_idle+0x22f/0x2d0
<4>[  416.209022]  cpu_startup_entry+0x14/0x20
<4>[  416.209025]  start_secondary+0x158/0x1a0
<4>[  416.209030]  secondary_startup_64+0xa4/0xb0
<4>[  416.209039] irq event stamp: 10186977
<4>[  416.209042] hardirqs last  enabled at (10186976): [<ffffffff810b9363>] tasklet_action_common.isra.17+0xe3/0x1c0
<4>[  416.209044] hardirqs last disabled at (10186977): [<ffffffff81a5e5ed>] _raw_spin_lock_irqsave+0xd/0x50
<4>[  416.209047] softirqs last  enabled at (10186968): [<ffffffff810b9a1a>] irq_enter_rcu+0x6a/0x70
<4>[  416.209049] softirqs last disabled at (10186969): [<ffffffff81c00f4f>] asm_call_on_stack+0xf/0x20

<4>[  416.209317] list_del corruption, ffff8882781bb870->next is LIST_POISON1 (dead000000000100)
<4>[  416.209317] WARNING: CPU: 7 PID: 46 at lib/list_debug.c:47 __list_del_entry_valid+0x4e/0x90
<4>[  416.209317] Modules linked in: i915(+) vgem snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio mei_hdcp x86_pkg_temp_thermal coretemp ax88179_178a usbnet mii crct10dif_pclmul snd_intel_dspcfg crc32_pclmul snd_hda_codec snd_hwdep ghash_clmulni_intel snd_hda_core e1000e snd_pcm ptp pps_core mei_me mei prime_numbers intel_lpss_pci [last unloaded: i915]
<4>[  416.209317] CPU: 7 PID: 46 Comm: ksoftirqd/7 Tainted: G     U  W         5.8.0-CI-CI_DRM_8852+ #1
<4>[  416.209317] Hardware name: Intel Corporation Ice Lake Client Platform/IceLake Y LPDDR4x T4 RVP TLC, BIOS ICLSFWR1.R00.3212.A00.1905212112 05/21/2019
<4>[  416.209317] RIP: 0010:__list_del_entry_valid+0x4e/0x90
<4>[  416.209317] Code: 2e 48 8b 32 48 39 fe 75 3a 48 8b 50 08 48 39 f2 75 48 b8 01 00 00 00 c3 48 89 fe 48 89 c2 48 c7 c7 38 19 33 82 e8 62 e0 b6 ff <0f> 0b 31 c0 c3 48 89 fe 48 c7 c7 70 19 33 82 e8 4e e0 b6 ff 0f 0b
<4>[  416.209317] RSP: 0018:ffffc90000280de8 EFLAGS: 00010086
<4>[  416.209317] RAX: 0000000000000000 RBX: ffff8882781bb848 RCX: 0000000000010104
<4>[  416.209317] RDX: 0000000000010104 RSI: ffffffff8238b4ee RDI: 00000000ffffffff
<4>[  416.209317] RBP: ffff8882781bb880 R08: 0000000000000000 R09: 0000000000000001
<4>[  416.209317] R10: 000000009fb6666e R11: 00000000feca9427 R12: ffffc90000280e18
<4>[  416.209317] R13: ffff8881951d5930 R14: dead0000000000d8 R15: ffff8882781bb880
<4>[  416.209317] FS:  0000000000000000(0000) GS:ffff88829c180000(0000) knlGS:0000000000000000
<4>[  416.209317] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4>[  416.209317] CR2: 0000556231326c48 CR3: 0000000005610001 CR4: 0000000000760ee0
<4>[  416.209317] PKRU: 55555554
<4>[  416.209317] Call Trace:
<4>[  416.209317]  <IRQ>
<4>[  416.209317]  remove_signaling_context.isra.13+0xd/0x70 [i915]
<4>[  416.209513]  signal_irq_work+0x1f7/0x4b0 [i915]

This is caused by virtual engines where although we take the breadcrumb
lock on each of the active engines, they may be different engines on
different requests, It turns out that the b->irq_lock was not a
sufficient proxy for the engine->active.lock in the case of more than
one request, so introduce an explicit lock around ce->signals.

v2: ce->signal_lock is acquired with only RCU protection and so must be
treated carefully and not cleared during reallocation. We also then need
to confirm that the ce we lock is the same as we found in the breadcrumb
list.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/2276
Fixes: c18636f76344 ("drm/i915: Remove requirement for holding i915_request.lock for breadcrumbs")
Fixes: 2854d866327a ("drm/i915/gt: Replace intel_engine_transfer_stale_breadcrumbs")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201126140407.31952-4-chris@chris-wilson.co.uk

drm/i915/gt: Protect context lifetime with RCU

Allow a brief period for continued access to a dead intel_context by
deferring the release of the struct until after an RCU grace period.
As we are using a dedicated slab cache for the contexts, we can defer
the release of the slab pages via RCU, with the caveat that individual
structs may be reused from the freelist within an RCU grace period. To
handle that, we have to avoid clearing members of the zombie struct.

This is required for a later patch to handle locking around virtual
requests in the signaler, as those requests may want to move between
engines and be destroyed while we are holding b->irq_lock on a physical
engine.

v2: Drop mutex_reinit(), if we never mark the mutex as destroyed we
don't need to reset the debug code, at the loss of having the mutex
debug code spot us attempting to destroy a locked mutex.
v3: As the intended use will remain strongly referenced counted, with
very little inflight access across reuse, drop the ctor.
v4: Drop the unrequired change to remove the temporary reference around
dropping the active context, and add back some more missing ctor
operations.
v5: The ctor is back. Tvrtko spotted that ce->signal_lock [introduced
later] maybe accessed under RCU and so needs special care not to be
reinitialised.
v6: Don't mix SLAB_TYPESAFE_BY_RCU and RCU list iteration.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201126140407.31952-3-chris@chris-wilson.co.uk

drm/i915/gt: Check for a completed last request once

Pull the repeated check for the last active request being completed to a
single spot, when deciding whether or not execlist preemption is
required.

In doing so, we remove the tasklet kick, introduced with the completion
checks in commit 35f3fd8182ba ("drm/i915/execlists: Workaround switching
back to a completed context"), if we find the request was completed but
have not yet seen the corresponding CS event. This was devolving into a
busy spin of the tasklet while we waited for the event as the delivery
was not as instantaneous as expected. Under load this is sufficient to
exhaust the tasklet softirq timeslice, and force ksoftirqd. Quite
noticeable overhead for no apparent improvement in latency.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201126140407.31952-2-chris@chris-wilson.co.uk

drm/i915/gt: Decouple completed requests on unwind

Since the introduction of preempt-to-busy, requests can complete in the
background, even while they are not on the engine->active.requests list.
As such, the engine->active.request list itself is not in strict
retirement order, and we have to scan the entire list while unwinding to
not miss any. However, if the request is completed we currently leave it
on the list [until retirement], but we could just as simply remove it
and stop treating it as active. We would only have to then traverse it
once while unwinding in quick succession.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201126140407.31952-1-chris@chris-wilson.co.uk

drm/i915/gt: Program mocs:63 for cache eviction on gen9

Ville noticed that the last mocs entry is used unconditionally by the HW
when it performs cache evictions, and noted that while the value is not
meant to be writable by the driver, we should program it to a reasonable
value nevertheless.

As it turns out, we can change the value of mocs:63 and the value we
were programming into it would cause hard hangs in conjunction with
atomic operations.

v2: Add details from bspec about how it is used by HW

Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/2707
Fixes: 3bbaba0ceaa2 ("drm/i915: Added Programming of the MOCS")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
Cc: <stable@vger.kernel.org> # v4.3+
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201126140841.1982-1-chris@chris-wilson.co.uk

drm/i915/guc: Use correct lock for CT event handler

CT event handler is called under the gt->irq_lock from the interrupt
handling paths so make it the same from the init path. I don't think this
mismatch caused any functional issue but we need to wean the code of the
global i915->irq_lock.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201120095636.1987395-2-tvrtko.ursulin@linux.intel.com

drm/i915/guc: Use correct lock for accessing guc->mmio_msg

Guc->mmio_msg is set under the guc->irq_lock in guc_get_mmio_msg so it
should be consumed under the same lock from guc_handle_mmio_msg.

I am not sure if the overall flow here makes complete sense but at least
the correct lock is now used.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201120095636.1987395-1-tvrtko.ursulin@linux.intel.com

drm/i915/gt: Free stale request on destroying the virtual engine

Since preempt-to-busy, we may unsubmit a request while it is still on
the HW and completes asynchronously. That means it may be retired and in
the process destroy the virtual engine (as the user has closed their
context), but that engine may still be holding onto the unsubmitted
compelted request. Therefore we need to potentially cleanup the old
request on destroying the virtual engine. We also have to keep the
virtual_engine alive until after the sibling's execlists_dequeue() have
finished peeking into the virtual engines, for which we serialise with
RCU.

v2: Be paranoid and flush the tasklet as well.
v3: And flush the tasklet before the engines, as the tasklet may
re-attach an rb_node after our removal from the siblings.

Fixes: 6d06779e8672 ("drm/i915: Load balancing across a virtual engine")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201123113717.20500-4-chris@chris-wilson.co.uk

drm/i915/gt: Don't cancel the interrupt shadow too early

We currently want to keep the interrupt enabled until the interrupt after
which we have no more work to do. This heuristic was broken by us
kicking the irq-work on adding a completed request without attaching a
signaler -- hence it appearing to the irq-worker that an interrupt had
fired when we were idle.

Fixes: 2854d866327a ("drm/i915/gt: Replace intel_engine_transfer_stale_breadcrumbs")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201123113717.20500-3-chris@chris-wilson.co.uk

drm/i915/gt: Track signaled breadcrumbs outside of the breadcrumb spinlock

Make b->signaled_requests a lockless-list so that we can manipulate it
outside of the b->irq_lock.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201123113717.20500-2-chris@chris-wilson.co.uk

drm/i915/gt: Defer enabling the breadcrumb interrupt to after submission

Move the register slow register write and readback from out of the
critical path for execlists submission and delay it until the following
worker, shaving off around 200us. Note that the same signal_irq_work() is
allowed to run concurrently on each CPU (but it will only be queued once,
once running though it can be requeued and reexecuted) so we have to
remember to lock the global interactions as we cannot rely on the
signal_irq_work() itself providing the serialisation (in constrast to a
tasklet).

By pushing the arm/disarm into the central signaling worker we can close
the race for disarming the interrupt (and dropping its associated
GT wakeref) on parking the engine. If we loose the race, that GT wakeref
may be held indefinitely, preventing the machine from sleeping while
the GPU is ostensibly idle.

v2: Move the self-arming parking of the signal_irq_work to a flush of
the irq-work from intel_breadcrumbs_park().

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/2271
Fixes: e23005604b2f ("drm/i915/gt: Hold context/request reference while breadcrumbs are active")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201123113717.20500-1-chris@chris-wilson.co.uk

drm/i915/gt: Plug IPS into intel_rps_set

The old IPS interface did not match the RPS interface that we tried to
plug it into (bool vs int return). Once repaired, our minimal
selftesting is finally happy!

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201121190352.15996-1-chris@chris-wilson.co.uk

drm/i915/selftests: Small tweak to put the termination conditions together

If we run out of ring space, or exceed the desired runtime, we wish to
stop the subtest. Put these checks together, so that we always keep the
requests flushed on completion.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201120140314.24749-3-chris@chris-wilson.co.uk

drm/i915/selftests: Improve granularity for mocs reset checks

Allow us to validate mocs configurations after reset if we have either
engine or global reset.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201120140314.24749-2-chris@chris-wilson.co.uk

drm/i915/gem: Remove incorrect early dbg print

We print out the "logical" context support before we discover whether or
not the engines have logical contexts. No one, except Tvrtko, seems to
have noticed the error, so the debug message must not be useful to
anyone.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201120140314.24749-1-chris@chris-wilson.co.uk

drm/i915: Show timeline dependencies for debug

Include the signalers each request in the timeline is waiting on, as a
means to try and identify the cause of a stall. This can be quite
verbose, even as for now we only show each request in the timeline and
its immediate antecedents.

This generates output like:

Timeline 886: { count 1, ready: 0, inflight: 0, seqno: { current: 664, last: 666 }, engine: rcs0 }
  U 886:29a-  prio=0 @ 134ms: gem_exec_parall<4621>
    U bc1:27a-  prio=0 @ 134ms: gem_exec_parall[4917]
Timeline 825: { count 1, ready: 0, inflight: 0, seqno: { current: 802, last: 804 }, engine: vcs0 }
  U 825:324  prio=0 @ 107ms: gem_exec_parall<4518>
    U b75:140-  prio=0 @ 110ms: gem_exec_parall<5486>
Timeline b46: { count 1, ready: 0, inflight: 0, seqno: { current: 782, last: 784 }, engine: vcs0 }
  U b46:310-  prio=0 @ 70ms: gem_exec_parall<5428>
    U c11:170-  prio=0 @ 70ms: gem_exec_parall[5501]
Timeline 96b: { count 1, ready: 0, inflight: 0, seqno: { current: 632, last: 634 }, engine: vcs0 }
  U 96b:27a-  prio=0 @ 67ms: gem_exec_parall<4878>
    U b75:19e-  prio=0 @ 67ms: gem_exec_parall<5486>

Signed-off-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>
Link: https://patchwork.freedesktop.org/patch/msgid/20201119165616.10834-6-chris@chris-wilson.co.uk

drm/i915: Lift waiter/signaler iterators

Lift the list iteration defines for traversing the signaler/waiter lists
into i915_scheduler.h for reuse.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201119165616.10834-5-chris@chris-wilson.co.uk

drm/i915/gt: Show all active timelines for debugging

Include the active timelines for debugfs/i915_engine_info, so that we
can see which have unready requests inflight which are not shown
otherwise.

Suggested-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201119165616.10834-4-chris@chris-wilson.co.uk

drm/i915/gt: Update request status flags for debug pretty-printer

We plan to expand upon the number of available statuses for when we
pretty-print the requests along the timelines, and so need a new set of
flags. We have settled upon:

Unready [U]
  - initial status after being submitted, the request is not
    ready for execution as it is waiting for external fences

Ready [R]
  - all fences the request was waiting on have been signaled,
            and the request is now ready for execution and will be
    in a backend queue

  - a ready request may still need to wait on semaphores
    [internal fences]

Ready/virtual [V]
  - same as ready, but queued over multiple backends

Executing [E]
  - the request has been transferred from the backend queue and
    submitted for execution on HW

  - a completed request may still be regarded as executing, its
    status may not be updated until it is retired and removed
    from the lists

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201119165616.10834-3-chris@chris-wilson.co.uk

drm/i915: Lift i915_request_show()

Extract i915_request_show for reuse in other request chain pretty
printers.

For a bonus point, quietly change the seqno format from %llx to %lld to
match everywhere else.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201119165616.10834-2-chris@chris-wilson.co.uk

drm/i915/gt: Include semaphore status in print_request()

When pretty-printing the requests for debug, also show the status of any
semaphore waits as part of its runnable status.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201119165616.10834-1-chris@chris-wilson.co.uk

drm/i915/gvt: Remove incorrect kerneldoc marking

Just a normal comment, not a kerneldoc function description.

drivers/gpu/drm/i915/gvt/handlers.c:1666: warning: Function parameter or member 'vgpu' not described in 'bxt_ppat_low_write'
drivers/gpu/drm/i915/gvt/handlers.c:1666: warning: Function parameter or member 'offset' not described in 'bxt_ppat_low_write'
drivers/gpu/drm/i915/gvt/handlers.c:1666: warning: Function parameter or member 'p_data' not described in 'bxt_ppat_low_write'
drivers/gpu/drm/i915/gvt/handlers.c:1666: warning: Function parameter or member 'bytes' not described in 'bxt_ppat_low_write'

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201103204307.15723-1-chris@chris-wilson.co.uk

drm/i915/gt: Remember to free the virtual breadcrumbs

Since we allocate some breadcrumbs for the virtual engine, and the
virtual engine has a custom destructor, we also need to free the
breadcrumbs after use.

Fixes: b3786b29379c ("drm/i915/gt: Distinguish the virtual breadcrumbs from the irq breadcrumbs")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201118133839.1783-1-chris@chris-wilson.co.uk

drm/i915/gt: Ignore dt==0 for reporting underflows

The presumption was that some time would always elapse between recording
the start and the finish of a context switch. This turns out to be a
regular occurrence and emitting a debug statement superfluous.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201117113103.21480-4-chris@chris-wilson.co.uk

drm/i915/dg1: make Wa_22010271021 permanent

Just like for rkl and tgl, this should be permanent as well for dg1
instead just for A0. The commit making it permanent for those platforms
ended up "racing" with the commit adding the DG1 WAs, so now fix that up.

v2: Add "tgl,dg1" to WA comment (Matt)

Cc: Swathi Dhanavanthri <swathi.dhanavanthri@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201027043228.696518-3-lucas.demarchi@intel.com

drm/i915/selftests: Fix wrong return value of perf_request_latency()

If intel context create failed, the perf_request_latency() will return 0
rather than error, because we doesn't initialize the return value.

Fixes: 25c26f18ea79 ("drm/i915/selftests: Measure dispatch latency")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201116143540.3648870-1-zhangxiaoxu5@huawei.com

drm/i915/selftests: Fix wrong return value of perf_series_engines()

If intel context create failed, the perf_series_engines() will return 0
rather than error, because we doesn't initialize the return value.

Fixes: cbfd3a0c5a55 ("drm/i915/selftests: Add request throughput measurement to perf")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201116144112.3673011-1-zhangxiaoxu5@huawei.com

drm/i915: Avoid memory leak with more than 16 workarounds on a list

I forgot to free the old list when growing past 16 entries.

Luckily, as much as I checked, none of the current platforms has more than
16 workarounds on a single list.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Fixes: 452420d22d5b ("drm/i915: Fuse per-context workaround handling with the common framework")
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201113132510.2298483-1-tvrtko.ursulin@linux.intel.com

Merge branch 'linux-5.11' of git://github.com/skeggsb/linux into drm-next

-next fix for type stuff.

Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Ben Skeggs <skeggsb@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/CACAvsv5vuM54oU1Yp8sX5ZVmJAv+-oQRQj-AeaKFb3qs1EtP-g@mail.gmail.com

drm/nouveau/ttm: avoid using nouveau_drm.ttm.type_vram prior to nv50

Pre-NV50 chipsets don't currently use the MMU subsystem that later
chipsets use, and type_vram is negative here, leading to an OOB memory
access.

This was previously guarded by a chipset check, restore that.

Reported-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 5839172f0980 ("drm/nouveau: explicitly specify caching to use")
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com>

Merge tag 'drm-intel-gt-next-2020-11-12-1' of git://anongit.freedesktop.org/drm/drm-intel into drm-next

Cross-subsystem Changes:
- DMA mapped scatterlist fixes in i915 to unblock merging of
  https://lkml.org/lkml/2020/9/27/70 (Tvrtko, Tom)

Driver Changes:

- Fix for user reported issue #2381 (Graphical output stops with "switching to inteldrmfb from simple"):
  Mark ininitial fb obj as WT on eLLC machines to avoid rcu lockup during fbdev init (Ville, Chris)
- Fix for Tigerlake (and earlier) to avoid spurious empty CSB events leading to hang (Chris, Bruce)
- Delay execlist processing for Tigerlake to avoid hang (Chris)
- Fix for Tigerlake RCS engine health check through heartbeat (Chris)
- Fix for Tigerlake reserved MOCS entries (Ayaz, Chris)
- Fix Media power gate sequence on Tigerlake (Rodrigo)
- Enable eLLC caching of display buffers for SKL+ (Ville)
- Support parsing of oversize batches on Gen9 (Matt, Chris)
- Exclude low pages (128KiB) of stolen from use to avoid thrashing during reset (Chris)
- Flush engines before Tigerlake breadcrumbs (Chris)

- Use the local HWSP offset during submission (Chris)
- Flush coherency domains on first set-domain-ioctl (Chris, Zbigniew)
- Use the active reference on the vma while capturing to avoid use-after-free (Chris)
- Fix MOCS PTE setting for gen9+ (Ville)
- Avoid NULL dereference on IPS driver callback while unbinding i915 (Chris)
- Avoid NULL dereference from PT/PD stash allocation error (Matt)
- Hold request reference for canceling an active context (Chris)
- Avoid infinite loop on x86-32 when mapping a lot of objects (Chris)
- Disallow WC mappings when processor doesn't support them (Chris)
- Return correct error in i915_gem_object_copy_blt() error path (Dan)
- Return correct error in intel_context_create_request() error path (Maarten)
- Tune down GuC communication enabled/disabled messages to debug (Jani)
- Fix rebased commit "Remove i915_request.lock requirement for execution callbacks" (Chris)
- Cancel outstanding work after disabling heartbeats on an engine (Chris)
- Signal cancelled requests (Chris)
- Retire cancelled requests on unload (Chris)
- Scrub HW state on driver remove (Chris)
- Undo forced context restores after trivial preemptions (Chris)
- Handle PCI unbind in PMU code (Tvrtko)
- Fix CPU hotplug with multiple GPUs in PMU code (Trtkko)
- Correctly set SFC capability for video engines (Venkata)

- Update GuC code to use firmware v49.0.1 (John, Matthew B., Daniele, Oscar, Michel, Rodrigo, Michal)
- Improve GuC warnings on loading failure (John)
- Avoid ownership race in buffer pool by clearing age (Chris)
- Use MMIO to read CSB in case of failure (Chris, Mika)
- Show engine properties in engine state dump to indicate changes (Chris, Joonas)
- Break up error capture compression loops with cond_resched() (Chris)
- Reduce GPU error capture mutex hold time to avoid khungtaskd (Chris)
- Serialise debugfs i915_gem_objects with ctx->mutex (Chris)
- Always test execution status on closing the context and close if not persistent (Chris)
- Avoid mixing integer types during batch copies (Chris, Jared)
- Skip over MI_NOOP when parsing to avoid overhead (Chris)
- Hold onto an explicit ref to i915_vma_work.pinned (Chris)
- Perform all asynchronous waits prior to marking payload start (Chris)
- Pull phys pread/pwrite implementations to the backend (Matt)

- Improve record of hung engines in error state (Tvrtko)
- Allow backends to override pread implementation (Matt)
- Reinforce LRC poisoning checks to confirm context survives execution (Chris)
- Fix memory region max size calculation (Matt)
- Fix order when adding blocks to memory region (Matt)
- Eliminate unused intel_virtual_engine_get_sibling func (Chris)
- Cleanup kasan warning for on-stack (unsigned long) casting (Chris)
- Onion unwind for scratch page allocation failure (Chris)
- Poison stolen pages before use (Chris)
- Selftest improvements (Chris)

Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201112163407.GA20320@jlahtine-mobl.ger.corp.intel.com

drm/Kconfig: rename keembay config

This all caps looked ugly.

Signed-off-by: Dave Airlie <airlied@redhat.com>

Merge tag 'drm-misc-next-2020-11-12' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

drm-misc-next for 5.11:

UAPI Changes:

Cross-subsystem Changes:

Core Changes:

 - Remove pgprot_decrypt() before calling io_remap_pfn_range()
 - Revert "drm/dp_mst: Retrieve extended DPCD caps for topology manager"
 - ttm: Add multihop infrastructure
 - doc: Update dma-buf

Driver Changes:

 - amdgpu: Use TTM multihop
 - kmb: select DRM_MIPI_DSI and depend on ARCH_KEEMBAY; Fix build warning;
   Fix typos
 - nouveau: Use TTM multihop; Fix out-of-bounds access
 - radeon: Use TTM multihop
 - ingenic: Search for scaling coefficients to to 102% of screen size

Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20201112080115.GA7954@linux-uq9g

drm/kmb: fix spelling mistakes in drm_info and drm_dbg messages

There are two spelling mistakes of the word sync in drm_info
and drm_dbg messages. Fix these.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201109111225.1485190-1-colin.king@canonical.com

drm/kmb: Fix build warnings

Fixed the following W=1 kernel build warnings
 drivers/gpu/drm/kmb/kmb_plane.h:74:18: warning: ‘kmb_formats_v’
 defined but not used [-Wunused-const-variable=]
 drivers/gpu/drm/kmb/kmb_plane.h:61:18: warning: ‘kmb_formats_g’
 defined but not used [-Wunused-const-variable=]

Signed-off-by: Anitha Chrisanthus <anitha.chrisanthus@intel.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1605045169-2696-1-git-send-email-anitha.chrisanthus@intel.com

drm/nouveau: Fix out-of-bounds access when deferencing MMU type

The value of struct drm_device.ttm.type_vram can become -1 for unknown
types of memory (see nouveau_ttm_init()). This leads to an out-of-bounds
error when accessing struct nvif_mmu.type[]:

  [   18.304116] ==================================================================
  [   18.311649] BUG: KASAN: slab-out-of-bounds in nouveau_ttm_io_mem_reserve+0x17a/0x7e0 [nouveau]
  [   18.320415] Read of size 1 at addr ffff88810ffac1fe by task systemd-udevd/342
  [   18.327681]
  [   18.329208] CPU: 1 PID: 342 Comm: systemd-udevd Tainted: G            E     5.10.0-rc2-1-default+ #581
  [   18.338681] Hardware name: Dell Inc. OptiPlex 9020/0N4YC8, BIOS A24 10/24/2018
  [   18.346032] Call Trace:
  [   18.348536]  dump_stack+0xae/0xe5
  [   18.351919]  print_address_description.constprop.0+0x17/0xf0
  [   18.357787]  ? nouveau_ttm_io_mem_reserve+0x17a/0x7e0 [nouveau]
  [   18.363818]  __kasan_report.cold+0x20/0x38
  [   18.368099]  ? nouveau_ttm_io_mem_reserve+0x17a/0x7e0 [nouveau]
  [   18.374133]  kasan_report+0x3a/0x50
  [   18.377789]  nouveau_ttm_io_mem_reserve+0x17a/0x7e0 [nouveau]
  <...>
  [   18.767690] Allocated by task 342:
  [   18.773087]  kasan_save_stack+0x1b/0x40
  [   18.778890]  __kasan_kmalloc.constprop.0+0xbf/0xd0
  [   18.785646]  __kmalloc_track_caller+0x1be/0x390
  [   18.792165]  kstrdup_const+0x46/0x70
  [   18.797686]  kobject_set_name_vargs+0x2f/0xb0
  [   18.803992]  kobject_init_and_add+0x9d/0xf0
  [   18.810117]  ttm_mem_global_init+0x12c/0x210 [ttm]
  [   18.816853]  ttm_bo_global_init+0x4a/0x160 [ttm]
  [   18.823420]  ttm_bo_device_init+0x39/0x220 [ttm]
  [   18.830046]  nouveau_ttm_init+0x2c3/0x830 [nouveau]
  [   18.836929]  nouveau_drm_device_init+0x1b4/0x3f0 [nouveau]
  <...>
  [   19.105336] ==================================================================

Fix this error, by not using type_vram as an index if it's negative.
Assume default values instead.

The error was seen on Nvidia G72 hardware.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Acked-by: Christian König <christian.koenig@amd.com>
Fixes: 1cf65c45183a ("drm/ttm: add caching state to ttm_bus_placement")
Cc: Christian König <christian.koenig@amd.com>
Cc: Michael J. Ruhl <michael.j.ruhl@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: VMware Graphics <linux-graphics-maintainer@vmware.com>
Cc: Roland Scheidegger <sroland@vmware.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Hawking Zhang <Hawking.Zhang@amd.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Likun Gao <Likun.Gao@amd.com>
Cc: dri-devel@lists.freedesktop.org
Cc: nouveau@lists.freedesktop.org
Cc: virtualization@lists.linux-foundation.org
Cc: spice-devel@lists.freedesktop.org
Cc: amd-gfx@lists.freedesktop.org
Link: https://patchwork.freedesktop.org/patch/msgid/20201110133655.13174-1-tzimmermann@suse.de

dma-buf: Document that dma-buf size is fixed

The fact that the size of dma-buf is invariant over the lifetime of the
buffer is mentioned in the comment of 'dma_buf_ops.mmap', but is not
documented at where the info is defined. Add the missing documentation.

Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/1605044477-51833-7-git-send-email-jianxin.xiong@intel.com

drm/i915/tgl: Fix Media power gate sequence.

Some media power gates are disabled by default. commit 5d86923060fc
("drm/i915/tgl: Enable VD HCP/MFX sub-pipe power gating")
tried to enable it, but it duplicated an existent register.
So, the main PG setup sequences ended up overwriting it.

So, let's now merge this to the main PG setup sequence.

v2: (Chris): s/BIT/REG_BIT, remove useless comment,
          remove useless =0, use the right gt,
     remove rc6 sequence doubt from commit message.

Fixes: 5d86923060fc ("drm/i915/tgl: Enable VD HCP/MFX sub-pipe power gating")
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: stable@vger.kernel.org#v5.5+
Cc: Dale B Stimson <dale.b.stimson@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201111072859.1186070-1-rodrigo.vivi@intel.com

drm/ingenic: ipu: Search for scaling coefs up to 102% of the screen

Increase the scaled image's theorical width/height until we find a
configuration that has valid scaling coefficients, up to 102% of the
screen's resolution. This makes sure that we can scale from almost
every resolution possible at the cost of a very small distorsion.
The CRTC_W / CRTC_H are not modified.

This algorithm was already in place but would not try to go above the
screen's resolution, and as a result would only work if the CRTC_W /
CRTC_H were smaller than the screen resolution. It will now try until it
reaches 102% of the screen's resolution.

Note that this algorithm exists mostly as a band-aid for a missing
functionality: it is not possible for userspace to request the closest
mode that would encapsulate the provided one, because the GEM buffer is
created beforehand. If there was a way to let the kernel tweak the mode,
I could write a better algorithm that would result in a better looking
picture.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201105083905.8780-1-paul@crapouillou.net

drm/radeon/ttm: use multihop

This removes the code to move resources directly between
SYSTEM and VRAM in favour of using the core ttm mulithop code.

Signed-off-by: Dave Airlie <airlied@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201109005432.861936-5-airlied@gmail.com

drm/nouveau/ttm: use multihop

This removes the code to move resources directly between
SYSTEM and VRAM in favour of using the core ttm mulithop code.

Signed-off-by: Dave Airlie <airlied@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201109005432.861936-4-airlied@gmail.com

drm/amdgpu/ttm: use multihop

This removes the code to move resources directly between
SYSTEM and VRAM in favour of using the core ttm mulithop code.

Signed-off-by: Dave Airlie <airlied@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201109005432.861936-3-airlied@gmail.com

drm/ttm: add multihop infrastrucutre (v3)

Currently drivers get called to move a buffer, but if they have to
move it temporarily through another space (SYSTEM->VRAM via TT)
then they can end up with a lot of ttm->driver->ttm call stacks,
if the temprorary space moves requires eviction.

Instead of letting the driver do all the placement/space for the
temporary, allow it to report back (-EMULTIHOP) and a placement (hop)
to the move code, which will then do the temporary move, and the
correct placement move afterwards.

This removes a lot of code from drivers, at the expense of
adding some midlayering. I've some further ideas on how to turn
it inside out, but I think this is a good solution to the call
stack problems.

v2: separate out the driver patches, add WARN for getting
MULTHOP in paths we shouldn't (Daniel)
v3: use memset (Christian)

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: hristian König <christian.koenig@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201109005432.861936-2-airlied@gmail.com

Revert "drm/dp_mst: Retrieve extended DPCD caps for topology manager"

This reverts commit ad44c03208e46b83e4ae3269e32c9e524aa71cf8.

Currently DRM driver assume the source device caps is higher than the MST device
caps. With this commit, this statement would be broken.

e.g. the source device only support DP1.2 and the mst device support DP1.4.

Signed-off-by: Koba Ko <koba.ko@canonical.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201103034907.72129-1-koba.ko@canonical.com

drm: remove pgprot_decrypted() before calls to io_remap_pfn_range()

commit f8f6ae5d077a ("mm: always have io_remap_pfn_range() set
pgprot_decrypted()") moves the pgprot_decrypted() into
io_remap_pfn_range(). Delete any, now confusing, open coded calls that
directly precede io_remap_pfn_range():

- drm_io_prot() is only in drm_mmap_locked() to call io_remap_pfn_range()

- fb_mmap() immediately calls vm_iomap_memory() which is a convenience
  wrapper for io_remap_pfn_range()

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/0-v1-2e6a0db57868+166-drm_sme_clean_jgg@nvidia.com

drm: DRM_KMB_DISPLAY should depend on ARCH_KEEMBAY

The Intel Keem Bay display controller is only present on Intel Keem Bay
SoCs.  Hence add a dependency on ARCH_KEEMBAY, to prevent asking the
user about this driver when configuring a kernel without Intel Keem Bay
platform support.

Note that:
  1. The dependency on ARM is dropped, as Keem Bay SoCs are only
     supported in arm64 kernel builds,
  2. The dependencies on OF and COMMON_CLK can be dropped for
     compile-testing, as the driver builds fine regardless.

Fixes: ed794057b052b52a ("drm/kmb: Build files for KeemBay Display driver")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20201110144350.3279147-1-geert+renesas@glider.be