commit 4a15c75c ("drm/i915: Introduce per-engine workarounds")
refactored the workaround code to have functions per-engine, but didn't
call any of them from logical_xcs_ring_init. Since we do have a non-RCS
workaround for KBL (WaKBLVECSSemaphoreWaitPoll) we do need to call
intel_engine_init_workarounds for non-RCS engines.
Note that whitelist is still RCS-only.

v2: move the call to logical_ring_init (Chris)

Fixes: 4a15c75c ("drm/i915: Introduce per-engine workarounds")
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190110013232.8972-2-daniele.ceraolospurio@intel.com

Needs just a few additional includes here and there.

Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190108082709.3748-1-jani.nikula@intel.com

First move the low hanging fruit, the fields that are only initialized
runtime. Use RUNTIME_INFO() exclusively to access the fields.

Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/c24fe7a4b0492a888690c46814c0ff21ce2f12b1.1546267488.git.jani.nikula@intel.com

In preparation for removing the manual EMIT_FLUSH prior to emitting the
breadcrumb implement the flush inline with writing the breadcrumb for
execlists. Using one command to both flush and write the breadcrumb is
naturally a tiny bit faster than splitting it into two.
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/20181228153114.4948-1-chris@chris-wilson.co.uk

Having completed a test run of gem_eio across all machines in CI we also
observe the phenomenon (of lost interrupts after resetting the GPU) on
gen3 machines as well as the previously sighted gen6/gen7. Let's apply
the same HWSTAM workaround that was effective for gen6+ for all, as
although we haven't seen the same failure on gen4/5 it seems prudent to
keep the code the same.

As a consequence we can remove the extra setting of HWSTAM and apply the
register from a single site.

v2: Delazy and move the HWSTAM into its own function
v3: Mask off all HWSP writes on driver unload and engine cleanup.
v4: And what about the physical hwsp?
v5: No, engine->init_hw() is not called from driver_init_hw(), don't be
daft. Really scrub HWSTAM as early as we can in driver_init_mmio()
v6: Rename set_hwsp as it was setting the mask not the hwsp register.
v7: Ville pointed out that although vcs(bsd) was introduced for g4x/ilk,
per-engine HWSTAM was not introduced until gen6!

References: https://bugs.freedesktop.org/show_bug.cgi?id=108735Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181218102712.11058-1-chris@chris-wilson.co.uk

Define IS_GEN() similarly to our IS_GEN_RANGE(). but use gen instead of
gen_mask to do the comparison. Now callers can pass then gen as a parameter,
so we don't require one macro for each gen.

The following spatch was used to convert the users of these macros:

@@
expression e;
@@
(
- IS_GEN2(e)
+ IS_GEN(e, 2)
|
- IS_GEN3(e)
+ IS_GEN(e, 3)
|
- IS_GEN4(e)
+ IS_GEN(e, 4)
|
- IS_GEN5(e)
+ IS_GEN(e, 5)
|
- IS_GEN6(e)
+ IS_GEN(e, 6)
|
- IS_GEN7(e)
+ IS_GEN(e, 7)
|
- IS_GEN8(e)
+ IS_GEN(e, 8)
|
- IS_GEN9(e)
+ IS_GEN(e, 9)
|
- IS_GEN10(e)
+ IS_GEN(e, 10)
|
- IS_GEN11(e)
+ IS_GEN(e, 11)
)

v2: use IS_GEN rather than GT_GEN and compare to info.gen rather than
    using the bitmask
Signed-off-by: NLucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181212181044.15886-2-lucas.demarchi@intel.com

Currently we allocate a scratch page for each engine, but since we only
ever write into it for post-sync operations, it is not exposed to
userspace nor do we care for coherency. As we then do not care about its
contents, we can use one page for all, reducing our allocations and
avoid complications by not assuming per-engine isolation.

For later use, it simplifies engine initialisation (by removing the
allocation that required struct_mutex!) and means that we can always rely
on there being a scratch page.

v2: Check that we allocated a large enough scratch for I830 w/a

Fixes: 06e562e7f515 ("drm/i915/ringbuffer: Delay after EMIT_INVALIDATE for gen4/gen5") # v4.18.20
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108850Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181204141522.13640-1-chris@chris-wilson.co.uk
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: <stable@vger.kernel.org> # v4.18.20+
(cherry picked from commit 51797499)
[Joonas: Use new function in gen9_init_indirectctx_bb too]
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

Braswell is really picky about having our writes posted to memory before
we execute or else the GPU may see stale values. A wmb() is insufficient
as it only ensures the writes are visible to other cores, we need a full
mb() to ensure the writes are in memory and visible to the GPU.

The most frequent failure in flushing before execution is that we see
stale PTE values and execute the wrong pages.

References: 987abd5c ("drm/i915/execlists: Force write serialisation into context image vs execution")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181206084431.9805-3-chris@chris-wilson.co.uk
(cherry picked from commit 490b8c65)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

Currently we face a severe problem on Braswell that manifests as invalid
ppGTT accesses. The code tries to maintain the PDP (page directory
pointers) inside the context in two ways, direct write into the context
and a pipelined LRI update. The direct write into the context is
fundamentally racy as it is unserialised with any access (read or write)
the GPU is doing. By asserting that Braswell is not used with vGPU
(currently an unsupported platform) we can eliminate the dangerous
direct write into the context image and solely use the pipelined update.

However, the LRI of the PDP fouls up the GPU, causing it to freeze and
take out the machine with "forcewake ack timeouts". This seems possible
to workaround by preventing the GPU from sleeping (via means of
disabling the power-state management interface, i.e. forcing each ring
to remain awake) around the update. Equally, it seems an EMIT_INVALIDATE
before the LRI is sufficient to prevent the forcewake errors.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108656
References: https://bugs.freedesktop.org/show_bug.cgi?id=108714Signed-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/20181207090213.14352-3-chris@chris-wilson.co.uk

Move the common engine->emit_flush(EMIT_INVALIDATE) back to the backends
(where it was once previously) as we seek to specialise it in future
patches.
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/20181207090213.14352-1-chris@chris-wilson.co.uk

Gen11 fails to deliver wrt global observation point on
tail/entry updates and we sometimes see old entry.

Use clflush to forcibly evict our possibly stale copy
of the cacheline in hopes that we get fresh one from gpu.
Obviously there is something amiss in the coherency protocol so
this can be consired as a workaround until real cause
is found.

The working hardware will do the evict without our cue anyways,
so the cost in there should be ameliorated by that fact.

v2: for next pass, s/flush/evict, add reset (Chris)

References: https://bugzilla.freedesktop.org/show_bug.cgi?id=108315
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20181205134612.24822-1-mika.kuoppala@linux.intel.com

Braswell is really picky about having our writes posted to memory before
we execute or else the GPU may see stale values. A wmb() is insufficient
as it only ensures the writes are visible to other cores, we need a full
mb() to ensure the writes are in memory and visible to the GPU.

The most frequent failure in flushing before execution is that we see
stale PTE values and execute the wrong pages.

References: 987abd5c ("drm/i915/execlists: Force write serialisation into context image vs execution")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181206084431.9805-3-chris@chris-wilson.co.uk

We can move the remaining RCS workarounds applied to only gen8 to the
engine->wa_list, and then reduce all engine->init_hw callbacks to common
code. The benefit of using the new wa_list is that we verify that the
registers are indeed restored and keep their magic values.

v2: INSTPM_FORCE_ORDERING is already part of gen8_ctx_workarounds, and
as confirmed by the mmio verification is a part of the context image!
v3: MI_MODE is already part of gen8_ctx_workarounds...
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/20181206180713.6827-2-chris@chris-wilson.co.uk

We stopped re-applying the GT workarounds after engine reset since commit
59b449d5 ("drm/i915: Split out functions for different kinds of
workarounds").

Issue with this is that some of the GT workarounds live in the MMIO space
which gets lost during engine resets. So far the registers in 0x2xxx and
0xbxxx address range have been identified to be affected.

This losing of applied workarounds has obvious negative effects and can
even lead to hard system hangs (see the linked Bugzilla).

Rather than just restoring this re-application, because we have also
observed that it is not safe to just re-write all GT workarounds after
engine resets (GPU might be live and weird hardware states can happen),
we introduce a new class of per-engine workarounds and move only the
affected GT workarounds over.

Using the framework introduced in the previous patch, we therefore after
engine reset, re-apply only the workarounds living in the affected MMIO
address ranges.

v2:
 * Move Wa_1406609255:icl to engine workarounds as well.
 * Rename API. (Chris Wilson)
 * Drop redundant IS_KABYLAKE. (Chris Wilson)
 * Re-order engine wa/ init so latest platforms are first. (Rodrigo Vivi)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Bugzilla: https://bugzilla.freedesktop.org/show_bug.cgi?id=107945
Fixes: 59b449d5 ("drm/i915: Split out functions for different kinds of workarounds")
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: intel-gfx@lists.freedesktop.org
Acked-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20181203133341.10258-1-tvrtko.ursulin@linux.intel.com
(cherry picked from commit 4a15c75c)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

Currently we allocate a scratch page for each engine, but since we only
ever write into it for post-sync operations, it is not exposed to
userspace nor do we care for coherency. As we then do not care about its
contents, we can use one page for all, reducing our allocations and
avoid complications by not assuming per-engine isolation.

For later use, it simplifies engine initialisation (by removing the
allocation that required struct_mutex!) and means that we can always rely
on there being a scratch page.

v2: Check that we allocated a large enough scratch for I830 w/a

Fixes: 06e562e7f515 ("drm/i915/ringbuffer: Delay after EMIT_INVALIDATE for gen4/gen5") # v4.18.20
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108850Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181204141522.13640-1-chris@chris-wilson.co.uk
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: <stable@vger.kernel.org> # v4.18.20+

Convert the per context workaround handling code to run against the newly
introduced common workaround framework and fuse the two to use the
existing smarter list add helper, the one which does the sorted insert and
merges registers where possible.

This completes migration of all four classes of workarounds onto the
common framework.

Existing macros are kept untouched for smaller code churn.

v2:
 * Rename to list name ctx_wa_list and move from dev_priv to engine.

v3:
 * API rename and parameters tweaking. (Chris Wilson)
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/20181203133357.10341-1-tvrtko.ursulin@linux.intel.com

Instead of having a separate list of white-listed registers we can
trivially move this to the common workarounds framework.

This brings us one step closer to the goal of driving all workaround
classes using the same code.

v2:
 * Use GEM_DEBUG_WARN_ON for the sanity check. (Chris Wilson)

v3:
 * API rename. (Chris Wilson)
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/20181203125014.3219-6-tvrtko.ursulin@linux.intel.com

We stopped re-applying the GT workarounds after engine reset since commit
59b449d5 ("drm/i915: Split out functions for different kinds of
workarounds").

Issue with this is that some of the GT workarounds live in the MMIO space
which gets lost during engine resets. So far the registers in 0x2xxx and
0xbxxx address range have been identified to be affected.

This losing of applied workarounds has obvious negative effects and can
even lead to hard system hangs (see the linked Bugzilla).

Rather than just restoring this re-application, because we have also
observed that it is not safe to just re-write all GT workarounds after
engine resets (GPU might be live and weird hardware states can happen),
we introduce a new class of per-engine workarounds and move only the
affected GT workarounds over.

Using the framework introduced in the previous patch, we therefore after
engine reset, re-apply only the workarounds living in the affected MMIO
address ranges.

v2:
 * Move Wa_1406609255:icl to engine workarounds as well.
 * Rename API. (Chris Wilson)
 * Drop redundant IS_KABYLAKE. (Chris Wilson)
 * Re-order engine wa/ init so latest platforms are first. (Rodrigo Vivi)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Bugzilla: https://bugzilla.freedesktop.org/show_bug.cgi?id=107945
Fixes: 59b449d5 ("drm/i915: Split out functions for different kinds of workarounds")
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: intel-gfx@lists.freedesktop.org
Acked-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20181203133341.10258-1-tvrtko.ursulin@linux.intel.com

We inspect the requests under the assumption that they will be marked as
completed when they are removed from the queue. Currently however, in the
process of wedging the requests will be removed from the queue before they
are completed, so rearrange the code to complete the fences before the
locks are dropped.

<1>[  354.473346] BUG: unable to handle kernel NULL pointer dereference at 0000000000000250
<6>[  354.473363] PGD 0 P4D 0
<4>[  354.473370] Oops: 0000 [#1] PREEMPT SMP PTI
<4>[  354.473380] CPU: 0 PID: 4470 Comm: gem_eio Tainted: G     U            4.20.0-rc4-CI-CI_DRM_5216+ #1
<4>[  354.473393] Hardware name: Intel Corporation NUC7CJYH/NUC7JYB, BIOS JYGLKCPX.86A.0027.2018.0125.1347 01/25/2018
<4>[  354.473480] RIP: 0010:__i915_schedule+0x311/0x5e0 [i915]
<4>[  354.473490] Code: 49 89 44 24 20 4d 89 4c 24 28 4d 89 29 44 39 b3 a0 04 00 00 7d 3a 41 8b 44 24 78 85 c0 74 13 48 8b 93 78 04 00 00 48 83 e2 fc <39> 82 50 02 00 00 79 1e 44 89 b3 a0 04 00 00 48 8d bb d0 03 00 00
<4>[  354.473515] RSP: 0018:ffffc900001bba90 EFLAGS: 00010046
<4>[  354.473524] RAX: 0000000000000003 RBX: ffff8882624c8008 RCX: f34a737800000000
<4>[  354.473535] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8882624c8048
<4>[  354.473545] RBP: ffffc900001bbab0 R08: 000000005963f1f1 R09: 0000000000000000
<4>[  354.473556] R10: ffffc900001bba10 R11: ffff8882624c8060 R12: ffff88824fdd7b98
<4>[  354.473567] R13: ffff88824fdd7bb8 R14: 0000000000000001 R15: ffff88824fdd7750
<4>[  354.473578] FS:  00007f44b4b5b980(0000) GS:ffff888277e00000(0000) knlGS:0000000000000000
<4>[  354.473590] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4>[  354.473599] CR2: 0000000000000250 CR3: 000000026976e000 CR4: 0000000000340ef0
<4>[  354.473611] Call Trace:
<4>[  354.473622]  ? lock_acquire+0xa6/0x1c0
<4>[  354.473677]  ? i915_schedule_bump_priority+0x57/0xd0 [i915]
<4>[  354.473736]  i915_schedule_bump_priority+0x72/0xd0 [i915]
<4>[  354.473792]  i915_request_wait+0x4db/0x840 [i915]
<4>[  354.473804]  ? get_pwq.isra.4+0x2c/0x50
<4>[  354.473813]  ? ___preempt_schedule+0x16/0x18
<4>[  354.473824]  ? wake_up_q+0x70/0x70
<4>[  354.473831]  ? wake_up_q+0x70/0x70
<4>[  354.473882]  ? gen6_rps_boost+0x118/0x120 [i915]
<4>[  354.473936]  i915_gem_object_wait_fence+0x8a/0x110 [i915]
<4>[  354.473991]  i915_gem_object_wait+0x113/0x500 [i915]
<4>[  354.474047]  i915_gem_wait_ioctl+0x11c/0x2f0 [i915]
<4>[  354.474101]  ? i915_gem_unset_wedged+0x210/0x210 [i915]
<4>[  354.474113]  drm_ioctl_kernel+0x81/0xf0
<4>[  354.474123]  drm_ioctl+0x2de/0x390
<4>[  354.474175]  ? i915_gem_unset_wedged+0x210/0x210 [i915]
<4>[  354.474187]  ? finish_task_switch+0x95/0x260
<4>[  354.474197]  ? lock_acquire+0xa6/0x1c0
<4>[  354.474207]  do_vfs_ioctl+0xa0/0x6e0
<4>[  354.474217]  ? __fget+0xfc/0x1e0
<4>[  354.474225]  ksys_ioctl+0x35/0x60
<4>[  354.474233]  __x64_sys_ioctl+0x11/0x20
<4>[  354.474241]  do_syscall_64+0x55/0x190
<4>[  354.474251]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4>[  354.474260] RIP: 0033:0x7f44b3de65d7
<4>[  354.474267] Code: b3 66 90 48 8b 05 b1 48 2d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 81 48 2d 00 f7 d8 64 89 01 48
<4>[  354.474293] RSP: 002b:00007fff974948e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
<4>[  354.474305] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f44b3de65d7
<4>[  354.474316] RDX: 00007fff97494940 RSI: 00000000c010646c RDI: 0000000000000007
<4>[  354.474327] RBP: 00007fff97494940 R08: 0000000000000000 R09: 00007f44b40bbc40
<4>[  354.474337] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000c010646c
<4>[  354.474348] R13: 0000000000000007 R14: 0000000000000000 R15: 0000000000000000

v2: Avoid floating requests.
v3: Can't call dma_fence_signal() under the timeline lock!
v4: Can't call dma_fence_signal() from inside another fence either.
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/20181203113701.12106-2-chris@chris-wilson.co.uk

Since commit fd8526e5 ("drm/i915/execlists: Trust the CSB") we
actually broke the force-mmio mode for our execlists implementation. No
one noticed, so ergo no one is actually using an old vGPU host (where we
required the older method) and so can simply remove the broken support.

v2: csb_read can go as well (Mika)
Reported-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Fixes: fd8526e5 ("drm/i915/execlists: Trust the CSB")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181130125954.11924-1-chris@chris-wilson.co.uk

Mark A0 as the one and only pre-production variant of Kabylake and
remove its couple of workarounds, consigning them to the annals of
history.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Acked-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181128135325.10641-1-chris@chris-wilson.co.uk

Ensure that the writes into the context image are completed prior to the
register mmio to trigger execution. Although previously we were assured
by the SDM that all writes are flushed before an uncached memory
transaction (our mmio write to submit the context to HW for execution),
we have empirical evidence to believe that this is not actually the
case.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108656
References: https://bugs.freedesktop.org/show_bug.cgi?id=108315
References: https://bugs.freedesktop.org/show_bug.cgi?id=106887Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Acked-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181108081740.25615-1-chris@chris-wilson.co.uk
Cc: stable@vger.kernel.org
(cherry picked from commit 987abd5c)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

We have multiple instances of VCS but only remember to invalidate the
BSD caches on the first, ignoring the stale caches of any other engine.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181108140039.12254-1-chris@chris-wilson.co.uk

Ensure that the writes into the context image are completed prior to the
register mmio to trigger execution. Although previously we were assured
by the SDM that all writes are flushed before an uncached memory
transaction (our mmio write to submit the context to HW for execution),
we have empirical evidence to believe that this is not actually the
case.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108656
References: https://bugs.freedesktop.org/show_bug.cgi?id=108315
References: https://bugs.freedesktop.org/show_bug.cgi?id=106887Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Acked-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181108081740.25615-1-chris@chris-wilson.co.uk
Cc: stable@vger.kernel.org

GEM_WARN_ON currently has dangerous semantics where it is completely
compiled out on !GEM_DEBUG builds. This can leave users who expect it to
be more like a WARN_ON, just without a warning in non-debug builds, in
complete ignorance.

Another gotcha with it is that it cannot be used as a statement. Which is
again different from a standard kernel WARN_ON.

This patch fixes both problems by making it behave as one would expect.

It can now be used both as an expression and as statement, and also the
condition evaluates properly in all builds - code under the conditional
will therefore not unexpectedly disappear.

To satisfy call sites which really want the code under the conditional to
completely disappear, we add GEM_DEBUG_WARN_ON and convert some of the
callers to it. This one can also be used as both expression and statement.

>From the above it follows GEM_DEBUG_WARN_ON should be used in situations
where we are certain the condition will be hit during development, but at
a place in code where error can be handled to the benefit of not crashing
the machine.

GEM_WARN_ON on the other hand should be used where condition may happen in
production and we just want to distinguish the level of debugging output
emitted between the production and debug build.

v2:
 * Dropped BUG_ON hunk.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Tomasz Lis <tomasz.lis@intel.com>
Reviewed-by: NTomasz Lis <tomasz.lis@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181012063142.16080-1-tvrtko.ursulin@linux.intel.com

Inside the execlists submission tasklet, we often make the mistake of
assuming that everything beneath the request is available for use.
However, the submission and the request live on two separate timelines,
and the request contents may be freed from an early retirement before we
have had a chance to run the submission tasklet (think ksoftirqd). To
safeguard ourselves against any mistakes, flush the tasklet before we
unpin the context if execlists still has a reference to this context.

v2: Pull hw_context->active tracking into schedule_in and schedule_out.

References: 60367132 ("drm/i915: Avoid use-after-free of ctx in request tracepoints")
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/20181003110941.27886-1-chris@chris-wilson.co.uk

Currently, the backend scheduling code abuses struct_mutex into order to
have a global lock to manipulate a temporary list (without widespread
allocation) and to protect against list modifications. This is an
extraneous coupling to struct_mutex and further can not extend beyond
the local device.

Pull all the code that needs to be under the one true lock into
i915_scheduler.c, and make it so.
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/20181001144755.7978-2-chris@chris-wilson.co.uk

Taken from an idea used for FQ_CODEL, we give the first request of a
new request flows a small priority boost. These flows are likely to
correspond with short, interactive tasks and so be more latency sensitive
than the longer free running queues. As soon as the client has more than
one request in the queue, further requests are not boosted and it settles
down into ordinary steady state behaviour.  Such small kicks dramatically
help combat the starvation issue, by allowing each client the opportunity
to run even when the system is under heavy throughput load (within the
constraints of the user selected priority).

v2: Mark the preempted request as the start of a new flow, to prevent a
single client being continually gazumped by its peers.

Testcase: igt/benchmarks/rrul
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181001144755.7978-1-chris@chris-wilson.co.uk

As we are about to allow ourselves to slightly bump the user priority
into a few different sublevels, packthose internal priority lists
into the same i915_priolist to keep the rbtree compact and avoid having
to allocate the default user priority even after the internal bumping.
The downside to having an requests[] rather than a node per active list,
is that we then have to walk over the empty higher priority lists. To
compensate, we track the active buckets and use a small bitmap to skip
over any inactive ones.

v2: Use MASK of internal levels to simplify our usage.
v3: Prevent overflow when SHIFT is zero.
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/20181001123204.23982-4-chris@chris-wilson.co.uk

If the request is currently on the HW (in port 0), then we do not need
to kick the submission tasklet to evaluate whether we should be
preempting itself in order to execute it again.

In the case that was annoying me:

   execlists_schedule: rq(18:211173).prio=0 -> 2
   need_preempt: last(18:211174).prio=0, queue.prio=2

We are bumping the priority of the first of a pair of requests running
in the current context. Then when evaluating preempt, we would see that
that our priority request is higher than the last executing request in
ELSP0 and so trigger preemption, not realising that our intended request
was already executing.

v2: As we assume state of the execlists->port[] that is only valid while
we hold the timeline lock we have to repeat some earlier tests that on
the validity of the node.
v3: Wrap guc submission under the timeline.lock as is now the way of all
things.
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/20180925083205.2229-2-chris@chris-wilson.co.uk

Now that we are confident in providing full-ppgtt where supported,
remove the ability to override the context isolation.

v2: Remove faked aliasing-ppgtt for testing as it no longer is accepted.
v3: s/USES/HAS/ to match usage and reject attempts to load the module on
old GVT-g setups that do not provide support for full-ppgtt.
v4: Insulate ABI ppGTT values from our internal enum (later plans
involve moving ppGTT depth out of the enum, thus potentially breaking
ABI unless we document the current values).
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Acked-by: NZhi Wang <zhi.a.wang@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180926201222.5643-1-chris@chris-wilson.co.uk

We mix hexa- and decimal which is confusing when reading the logs. So make
the single odd one out instance decimal for consistency.

v2:
 * Do the intel_ringbuffer.c as well. (Chris Wilson)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180926145033.16318-1-tvrtko.ursulin@linux.intel.com

Our execlist dispatch code requires a ppGTT so make sure we enforce that
option in intel_sanitize_enable_ppgtt(). The comment already tries to
explain that execlists requires ppgtt, but was written when gen8 may
have also taken the legacy path; so rewrite the code to match the
comment by using HAS_EXECLISTS() feature instead of the gen.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180922141804.21183-1-chris@chris-wilson.co.uk

In the sequence

<0>[  531.960431] drv_self-4806    7.... 527402570us : intel_gpu_reset: engine_mask=1, ret=0, retry=0
<0>[  531.960431] drv_self-4806    7.... 527402571us : execlists_reset: rcs0 request global=115de, current=71133
<0>[  531.960431] drv_self-4806    7d..1 527402571us : execlists_cancel_port_requests: rcs0:port0 global=71134 (fence 826b:198), (current 71133)
<0>[  531.960431] drv_self-4806    7d..1 527402572us : execlists_cancel_port_requests: rcs0:port1 global=71135 (fence 826c:53), (current 71133)
<0>[  531.960431] drv_self-4806    7d..1 527402572us : __i915_request_unsubmit: rcs0 fence 826c:53 <- global=71135, current 71133
<0>[  531.960431] drv_self-4806    7d..1 527402579us : __i915_request_unsubmit: rcs0 fence 826b:198 <- global=71134, current 71133
<0>[  531.960431] drv_self-4806    7.... 527402613us : intel_engine_cancel_stop_cs: rcs0
<0>[  531.960431] drv_self-4806    7.... 527402624us : execlists_reset_finish: rcs0

we are missing the execlists_submission_tasklet() invocation before the
execlists_reset_fini() implying that either the queue is empty, or we
failed to schedule and run the tasklet on finish. Add an assert so we
are sure that on unsubmitting the incomplete request after reset, the
queue is indeed populated.
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/20180919195544.1511-12-chris@chris-wilson.co.uk

Fix up the error unwind for logical_ring_init() failing by moving the
cleanup into the callers who own the various bits of state during
initialisation, so we don't forget to free the state allocated by the
caller.
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/20180920195948.16448-1-chris@chris-wilson.co.uk

That we use a WB mapping for updating the RING_TAIL register inside the
context image even on !llc machines has been a source of consternation
for every reader. It appears to work on bsw+, but it may just have been
that we have been incredibly bad at detecting the errors.

v2: With extra enthusiasm.
v3: Drop force of map type for pinned default_state as by the time we
pin it, the map type is always WB and doesn't conflict with the earlier
use by ce->state.
v4: Transfer engine->default_state from MAP_WC to MAP_WB on creation so
we do not need the MAP_FORCE littered around the backends
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/20180914123504.2062-3-chris@chris-wilson.co.uk

Now that we reload both RING_HEAD and RING_TAIL when rebinding the
context, we do not need to scrub those registers immediately on resume.

v2: Handle the perma-pinned contexts.
v3: Set RING_TAIL on context-pin so that we always have known state in
the context image for the ring registers and all parties have similar
code (ripe for refactoring).
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180914123504.2062-1-chris@chris-wilson.co.uk

Future gen reduce the number of bits we will have available to
differentiate between contexts, so reduce the lifetime of the ID
assignment from that of the context to its current active cycle (i.e.
only while it is pinned for use by the HW, will it have a constant ID).
This means that instead of a max of 2k allocated contexts (worst case
before fun with bit twiddling), we instead have a limit of 2k in flight
contexts (minus a few that have been pinned by the kernel or by perf).

To reduce the number of contexts id we require, we allocate a context id
on first and mark it as pinned for as long as the GEM context itself is,
that is we keep it pinned it while active on each engine. If we exhaust
our context id space, then we try to reclaim an id from an idle context.
In the extreme case where all context ids are pinned by active contexts,
we force the system to idle in order to recover ids.

We cannot reduce the scope of an HW-ID to an engine (allowing the same
gem_context to have different ids on each engine) as in the future we
will need to preassign an id before we know which engine the
context is being executed on.

v2: Improved commentary (Tvrtko) [I tried at least]

References: https://bugs.freedesktop.org/show_bug.cgi?id=107788Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180904153117.3907-1-chris@chris-wilson.co.uk

There are two issues with the current RPCS programming for Icelake:

Expansion of the slice count bitfield has been missed, as well as the
required programming workaround for the subslice count bitfield size
limitation.

1)

Bitfield width for configuring the active slice count has grown so we need
to program the GEN8_R_PWR_CLK_STATE accordingly.

Current code was always requesting eight times the number of slices (due
writing to a bitfield starting three bits higher than it should). These
requests were luckily a) capped by the hardware to the available number of
slices, and b) we haven't yet exported the code to ask for reduced slice
configurations.

Due both of the above there was no impact from this incorrect programming
but we should still fix it.

2)

Due subslice count bitfield being only three bits wide and furthermore
capped to a maximum documented value of four, special programming
workaround is needed to enable more than four subslices.

With this programming driver has to consider the GT configuration as
2x4x8, while the hardware internally translates this to 1x8x8.

A limitation stemming from this is that either a subslice count between
one and four can be selected, or a subslice count equaling the total
number of subslices in all selected slices. In other words, odd subslice
counts greater than four are impossible, as are odd subslice counts
greater than a single slice subslice count.

This also had no impact in the current code base due breakage from 1)
always reqesting more than one slice.

While fixing this we also add some asserts to flag up any future bitfield
overflows.

v2:
 * Use a local in all branches for clarity. (Lionel)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Bspec: 12247
Reported-by: tony.ye@intel.com
Suggested-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: tony.ye@intel.com
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180903113007.2643-1-tvrtko.ursulin@linux.intel.com

On finishing the reset, the intention is to restart the GPU before we
relinquish the forcewake taken to handle the reset - the goal being the
GPU reloads a context before it is allowed to sleep. For this purpose,
we used tasklet_flush() which although it accomplished the goal of
restarting the GPU, carried with it a sting in its tail: it cleared the
TASKLET_STATE_SCHED bit. This meant that if another CPU queued a new
request to this engine, we would clear the flag and later attempt to
requeue the tasklet on the local CPU, breaking the per-cpu softirq
lists.

Remove the dangerous tasklet_kill() and just run the tasklet func
directly as we know it is safe to do so (the tasklets are internally
locked to allow mixed usage from direct submission).
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180828152702.27536-1-chris@chris-wilson.co.uk