We already implement this workaround, but it was missing its name.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NMichel Thierry <michel.thierry@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Similar to a patch from Thomas Daniel for lrc contexts. This keeps
both sides somewhat in sync and should make Dave Gordon happy.

Note that both the wa and the golden context init code suffer a bit
from an inssuficient split into driver load and hw init code. Which
means we have a bunch of tests all over the place to check whether the
one-time initialization has been done already or not.

All that one-tim code should be moved into the one-time ring setup
code, but that's work for later.

Cc: Dave Gordon <david.s.gordon@intel.com>
Cc: Thomas Daniel <thomas.daniel@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For debugging purposes, it is useful to be able to uniquely identify a given
request structure as it works its way through the system. This becomes
especially tricky once the seqno value is lazily allocated as then the request
has nothing but its pointer to identify it for much of its life.

Change-Id: Ie76b2268b940467f4cdf5a4ba6f5a54cbb96445d
For: VIZ-4377
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NThomas Daniel <Thomas.Daniel@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There is a general theory that kzmalloc is better/safer than kmalloc, especially
for interesting data structures. This change updates the request structure
allocation to be zero filled.

This also fixes crashes in the reset code. Quoting Mika's patch:

"Clean the request structure on alloc. Otherwise we might end up
referencing uninitialized fields.  This is apparent when we try to
cleanup the preallocated request on ring reset, before any request has
been submitted to the ring.  The request->ctx is foobar and we end up
freeing the foobarness."

Note that this fixes a regression introduced in

commit 9eba5d4a
Author: John Harrison <John.C.Harrison@Intel.com>
Date:   Mon Nov 24 18:49:23 2014 +0000

    drm/i915: Ensure OLS & PLR are always in sync

References: https://bugs.freedesktop.org/show_bug.cgi?id=86959
References: https://bugs.freedesktop.org/show_bug.cgi?id=86962
References: https://bugs.freedesktop.org/show_bug.cgi?id=86992
Change-Id: I68715ef758025fab8db763941ef63bf60d7031e2
For: VIZ-4377
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NThomas Daniel <Thomas.Daniel@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We already have it for chv, but was missing for bdw.
Signed-off-by: NMichel Thierry <michel.thierry@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that sanity prevails and we have the clean split between software
init and starting the engines we can drop all the "have we allocate
this struct already?" nonsense.

Execlist code could benefit quite a bit more still, but that's for
another patch.
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

We can do this.

And now there's finally the clean split between software setup and
hardware setup I kinda wanted since multi-ring support was merged
aeons ago. It only took almost 5 years.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

With this all the ->init_hw hooks really only set up hw state needed
to start the ring, all the software state setup and memory/buffer
allocations happen beforehand.

v2: We need to call intel_init_pipe_control after the ring init since
otherwise engine->dev is NULL and it falls over. Currently that's
now after the hw ring is enabled but a) we'll be fine as long as no
one submits a batch b) this will change soon.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is (mostly, some exceptions that need fixing) the hw setup
function which starts the ring. And not the function which allocates
all the resources.

Make this clear by giving it a better name.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There are numerous places in the code where the driver's idea of
how much space is left in a ring is updated using the driver's
latest notions of the positions of 'head' and 'tail' for the ring.
Among them are some that update one or both of these values before
(re)doing the calculation. In particular, there are four different
places in the code where 'last_retired_head' is copied to 'head'
and then set to -1; and two of these do not have a guard to check
that it has actually been updated since last time it was consumed,
leaving the possibility that the dummy -1 can be transferred from
'last_retired_head' to 'head', causing the space calculation to
produce 'impossible' results (previously seen on Android/VLV).

This code therefore consolidates all the calculation and updating of
these values, such that there is only one place where the ring space
is updated, and it ALWAYS uses (and consumes) 'last_retired_head' if
(and ONLY if) it has been updated since the last call.
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The used space in a ring is given by the cyclic distance from the
consumer (HEAD) to the producer (TAIL), i.e. ((tail-head) MOD size);
conversely, the available space in a ring is the cyclic distance
from the producer to the consumer, MINUS the amount reserved for a
"gap" that is supposed to guarantee that the producer never catches
up with or overruns the consumer. Note that some GEN h/w requires
that TAIL never approach to within one cacheline of HEAD, so the gap
is usually set to twice the cacheline size to ensure this.

While the existing code gives the correct answer for correct inputs,
if the producer HAS overrun into the reserved space, the result can
be a value larger than the maximum valid value (size-reserved). We
can improve this by reorganising the calculation, so that in the
event of overrun the result will be negative rather than over-large.

This means that the commonly-used test (available >= required)
will then reject further writes into the ring after an overrun,
giving some chance that we can recover from or at least diagnose
the original problem; whereas allowing more writes would likely both
confuse the h/w and destroy the evidence of what went wrong.
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It makes a lot more sense (and makes future seqno -> request conversion patches
simpler) to fill in the 'ring' field of the request structure at the point of
creation rather than submission. Given that the request structure is assigned by
ring specific code and thus is locked to a ring from the start, there really is
no reason to defer this assignment.

For: VIZ-4377
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NThomas Daniel <Thomas.Daniel@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There is no longer any need to retrieve a seqno value from an i915_add_request()
call. The calling code already knows which request structure is being processed
(it can only be ring->OLR). And as the request itself is now used in preference
to the basic seqno value, the latter is now redundant in this situation.

For: VIZ-4377
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NThomas Daniel <Thomas.Daniel@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Updated i915_wait_seqno() to take a request structure instead of a seqno value
and renamed it accordingly. Internally, it just pulls the seqno out of the
request and calls on to __wait_seqno() as before. However, all the code further
up the stack is now simplified as it can just pass the request object straight
through without having to peek inside.

For: VIZ-4377
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NThomas Daniel <Thomas.Daniel@intel.com>
[danvet: Squash in hunk from an earlier patch which was rebased
wrongly.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The OLS value is now obsolete. Exactly the same value is guarateed to be always
available as PLR->seqno. Thus it is safe to remove the OLS completely. And also
to rename the PLR to OLR to keep the 'outstanding lazy ...' naming convention
valid.

For: VIZ-4377
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NThomas Daniel <Thomas.Daniel@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The plan is to use request structures everywhere that seqno values were
previously used. This means saving pointers to structures in places that used to
be simple integers. In turn, that means that the target structure now needs much
more stringent lifetime tracking. That is, it must not be freed while some other
random object still holds a pointer to it.

To achieve this tracking, a reference count needs to be added. Whenever a
pointer to the structure is saved away, the count must be incremented and the
free must only occur when all references have been released.

For: VIZ-4377
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NThomas Daniel <Thomas.Daniel@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The aim is to replace seqno values with request structures. A step along the way
is to switch to using the PLR in preference to the OLS. That requires the PLR to
only be valid when and only when the OLS is also valid. I.e., the two must be
kept in lock step. Then, code which was using the OLS can be safely switched
over to using the PLR instead.

For: VIZ-4377
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NThomas Daniel <Thomas.Daniel@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

With the deprecation of UMS, and by association DRI1, we have a tough
choice when updating the ring access routines. We either rewrite the
DRI1 routines blindly without testing (so likely to be broken) or take
the liberty of declaring them no longer supported and remove them
entirely. This takes the latter approach.

v2: Also remove the DRI1 sarea updates
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Fix rebase conflicts.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Same as with the context, pinning to GGTT regardless is harmful (it
badly fragments the GGTT and can even exhaust it).

Unfortunately, this case is also more complex than the previous one
because we need to map and access the ringbuffer in several places
along the execbuffer path (and we cannot make do by leaving the
default ringbuffer pinned, as before). Also, the context object
itself contains a pointer to the ringbuffer address that we have to
keep updated if we are going to allow the ringbuffer to move around.

v2: Same as with the context pinning, we cannot really do it during
an interrupt. Also, pin the default ringbuffers objects regardless
(makes error capture a lot easier).

v3: Rebased. Take a pin reference of the ringbuffer for each item
in the execlist request queue because the hardware may still be using
the ringbuffer after the MI_USER_INTERRUPT to notify the seqno update
is executed.  The ringbuffer must remain pinned until the context save
is complete.  No longer pin and unpin ringbuffer in
populate_lr_context() - this transient address is meaningless and the
pinning can cause a sleep while atomic.

v4: Moved ringbuffer pin and unpin into the lr_context_pin functions.
Downgraded pinning check BUG_ONs to WARN_ONs.

v5: Reinstated WARN_ONs for unexpected execlist states.  Removed unused
variable.

Issue: VIZ-4277
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Signed-off-by: NThomas Daniel <thomas.daniel@intel.com>
Reviewed-by: NAkash Goel <akash.goels@gmail.com>
Reviewed-by: Deepak S<deepak.s@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Following the legacy ring submission example, update the
ring->init_context() hook to support the execlist submission mode.

v2: update to use the new workaround macros and cleanup unused code.
This takes care of both bdw and chv workarounds.

v2.1: Add missing call to init_context() during deferred context creation.

v3: Split init_context (emit) in legacy/lrc modes. For lrc, get the ringbuf
from the context (Mika/Daniel).

v4: Merge init_context interfaces back, the legacy mode only needs the ring,
but the lrc mode needs the ring and context (Mika).

Issue: VIZ-4092
Issue: GMIN-3475
Change-Id: Ie3d093b2542ab0e2a44b90460533e2f979788d6c
Cc: Deepak S <deepak.s@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: NMichel Thierry <michel.thierry@intel.com>
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
[danvet: Align function paramater lists properly.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

+WaForceEnableNonCoherent:chv
+WaHdcDisableFetchWhenMasked:chv

For: VIZ-4090
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

WaDisablePartialInstShootdown:chv and
WaDisableThreadStallDopClockGating:chv are related to the same
register so combine them.
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

-WaDisableDopClockGating:chv
-WaDisableSamplerPowerBypass:chv
-WaDisableGunitClockGating:chv
-WaDisableFfDopClockGating:chv
-WaDisableDopClockGating:chv

v2: Remove pre-production WA instead of restricting them
based on revision id (Ville)

For: VIZ-4090
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If a ring failed to initialise for any reason then the error path would try to
clean up all rings including those that had not yet been allocated. The ring
clean up code did a check that the ring was valid before starting its work.
Unfortunately, that was after it had already dereferenced the ring to obtain a
dev_private pointer.
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The number of DWords should be even when doing ring emits as
command sequences require QWord alignment.

There was some discussion about the maximum length of the MI_LRI
command. Quoting Mika

"I did some test with bdw:

"The maximum is 128 writes, resulting the 8 bit length
field of the command being 0xff, thus following the spec.
The 128'th write went through.

"Perhaps the max command length is then less in older gens?

"Perhaps WARN_ON(x > 128) in MI_LOAD_REGISTER_IMM would be in place
but one needs minor tweak to command parser a bit also then.

	#define I915_MAX_WA_REGS 16

keeps us safe for now atleast."

Ville commented that on pre-gen6 the length field seems to be
restricted to 0x3f though. So for all cases we should be ok.

v2: user LRI variant that can write multiple regs in one go (Damien).
We can simply insert one NOP at the end instead of one per register write.

Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
[danvet: Add a summary of the MI_LRI length discussion.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If we build the workaround list in ring initialization
and decouple it from the actual writing of values, we
gain the ability to decide where and how we want to apply
the values.

The advantage of this will become more clear when
we need to initialize workarounds on older gens where
it is not possible to write all the registers through ring
LRIs.

v2: rebase on newest bdw workarounds

Cc: Arun Siluvery <arun.siluvery@linux.intel.com>
Cc: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NArun Siluvery <arun.siluvery@linux.intel.com>
[danvet: Resolve tiny conflict in comments and ocd alignments a bit.]
[danvet2: Remove bogus force_wake_get call spotted by Paulo and QA.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Let's clean this a bit

v2: Rebase after other Mika's patch that removed some BDW production workarounds.
v3: Removed stepping info.
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This WA affect BDW GT3 pre-production steppings.
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
[danvet: Don't mention steppings ...]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The sw cache clean on BDW is a tempoorary workaround because we cannot
set cache clean on blt ring with risk of hungs. So we are doing the cache clean on sw.
However we are doing much more than needed. Not only when using blt ring.
So, with this extra w/a we minimize the ammount of cache cleans and call it only
on same cases that it was being called on gen7.

The traditional FBC Cache clean happens over LRI on BLT ring when there is a
frontbuffer touch happening. frontbuffer tracking set fbc_dirty variable
to let BLT flush that it must clean FBC cache.

fbc.need_sw_cache_clean works in the opposite information direction
of ring->fbc_dirty telling software on frontbuffer tracking to perform
the cache clean on sw side.

v2: Clean it a little bit and fully check for Broadwell instead of gen8.

v3: Rebase after frontbuffer organization.

v4: Wiggle confused me. So fixing v3!

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The following sets the AsyncFlip performance mode for everything above
Gen6:

commit 4790cb36b3eede8fb0cca529dc1d31b9936fa24b
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Sun Jan 20 16:11:20 2013 +0000

    drm/i915: Disable AsyncFlip performance optimisations

Starting from Gen9 the MI_MODE register layout changes and doesn't
include the above bit.
Reviewed-by: NThomas Wood <thomas.wood@intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

as these have been fixed in production hw and hurt performance
if applied.

v2: adjust requested ring space (Ville)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=83482Tested-by: Nzhoujian <jianx.zhou@intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Yet another place that wasn't properly transformed when implementing
SOix. While at it convert the checks to WARN_ON on gen5+ (since we
don't have UMS potentially doing stupid things on those platforms).
And also add the corresponding checks to the put functions (again with
a WARN_ON) for gen5+.

v2: Drop the WARNINGS in the irq_put functions (including the existing
one for vebox), Chris convinced me that they're not that terribly
useful.

v3: Don't forget about execlist code.

Cc: Imre Deak <imre.deak@intel.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: "Volkin, Bradley D" <bradley.d.volkin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

gen6 and earlier conflate address space selection (ppgtt vs ggtt) with
the security bit (i.e. only privileged batches were allowed to run from
ggtt). From Haswell only, you are able to select the security bit
separate from the address space - and we always requested to use ppgtt.
This breaks the golden render state batch execution with full-ppgtt as
that is only present in the global GTT and more generally any secure
batch that is not colocated in the ppgtt and ggtt. So we need to
disable the use of the ppgtt selector bit for secure batches, or else we
hang immediately upon boot and thence after every GPU reset...

v2: Only HSW differentiates between secure dispatch and ggtt, so simply
ignore the differentiation and always use secure==ggtt.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
[danvet: Rectify commit message as noted by Chris.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

One small change I forgot to make in

commit c4d69da1
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Mon Sep 8 14:25:41 2014 +0100

    drm/i915: Evict CS TLBs between batches

was to update the copy width for the compact BLT copy instruction.
Reported-by: NThomas Richter <thor@math.tu-berlin.de>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Thomas Richter <thor@math.tu-berlin.de>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: stable@vger.kernel.org
Tested-by: NThomas Richter <thor@math.tu-berlin.de>
Acked-by: NDaniel Vetter <daniel@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Running igt, I was encountering the invalid TLB bug on my 845g, despite
that it was using the CS workaround. Examining the w/a buffer in the
error state, showed that the copy from the user batch into the
workaround itself was suffering from the invalid TLB bug (the first
cacheline was broken with the first two words reversed). Time to try a
fresh approach. This extends the workaround to write into each page of
our scratch buffer in order to overflow the TLB and evict the invalid
entries. This could be refined to only do so after we update the GTT,
but for simplicity, we do it before each batch.

I suspect this supersedes our current workaround, but for safety keep
doing both.

v2: The magic number shall be 2.

This doesn't conclusively prove that it is the mythical TLB bug we've
been trying to workaround for so long, that it requires touching a number
of pages to prevent the corruption indicates to me that it is TLB
related, but the corruption (the reversed cacheline) is more subtle than
a TLB bug, where we would expect it to read the wrong page entirely.

Oh well, it prevents a reliable hang for me and so probably for others
as well.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Ville found an old w/a documented for g4x that suggested that we need to
reset the HEAD after writing START. This is a useful fixup for some of
the g4x ring initialisation woes, but as usual, not all.

v2: Do the rewrite unconditionally anyway

References: https://bugs.freedesktop.org/show_bug.cgi?id=76554Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If we happen to emit more than I915_MAX_WA_REGS workarounds, we will
currently discard them, not even emit the LRI. Not really what we want,
so warn loudly.
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

When entering intel_ring_emit_wa() with num_wa_regs equal to
I915_MAX_WA_REGS, we end up indexing the intel_wa_regs array beyond its
allocation.

Fix the check then.
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Follow the BDW example and apply the workarounds touching registers
which are saved in the context image through LRIs in the new
ring->init_context() hook.

This makes Mesa much happier and eg. glxgears doesn't hang after
the first frame.

Cc: Arun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
[danvet: Add missing wa table initialization to avoid a functional
conflict with Arun's wa table debugfs support.]
Reviewed-by: N"Barbalho, Rafael" <rafael.barbalho@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>