For BXT, description of polarities of PORT_PLL_REF_SEL
has been reversed for newer Gen9LP steppings according to the
recent update in Bspec. This bit now should be set for
"Non-SSC" mode for all Gen9LP starting from B0 stepping.

v2: Only B0 and newer stepping should be affected by this
change.
Signed-off-by: NDongwon Kim <dongwon.kim@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94866Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458176773-26925-1-git-send-email-dongwon.kim@intel.com

Check functions are used by atomic to see if the new state will
be allowed. There's also a hw state checker which checks afterwards
that the committed state is correct. Rename it to hw state verifier
to reduce some confusion.
Suggested-by: NMatt Roper <matthew.d.roper@intel.com>
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/56FB8785.8020506@linux.intel.comReviewed-by: NMatt Roper <matthew.d.roper@intel.com>

The modeset state verifier no longer has full access to the hardware,
instead it should only verify affected crtc's.

Looking for disabled stuff can be verified immediately after all crtc
disables have completed, while each enabled crtc can be verified right
after being enabled.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458741487-23801-3-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NMatt Roper <matthew.d.roper@intel.com>
[mlankhorst: check -> verify]

This will make it easier to keep the crtc checker when atomic
commit is reworked for asynchronous commits. This prevents checking
crtc's that were not part of the state. It's safe to verify disabled
encoders, connectors and dpll's that are not part of the state,
because during modeset connection_mutex is held.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458741487-23801-2-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NMatt Roper <matthew.d.roper@intel.com>
[mlankhorst: Extend commit message and rename check to verify.]

When reading from the HWS page, we use barrier() to prevent the compiler
optimising away the read from the volatile (may be updated by the GPU)
memory address. This is more suited to READ_ONCE(); make it so.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460195877-20520-5-git-send-email-chris@chris-wilson.co.uk

Rather than call a function to compute the matching cachelines and
clflush them, just call the clflush *instruction* directly. We also know
that we can use the unpatched plain clflush rather than the clflushopt
alternative.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460195877-20520-4-git-send-email-chris@chris-wilson.co.uk

Only declare a missed interrupt if we find that the GPU is idle with
waiters and a hangcheck interval has passed in which no new user
interrupts have been raised.

v2: Clear the stuck interrupt marker between successful batches
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460195877-20520-3-git-send-email-chris@chris-wilson.co.uk

In order to simplify future patches, extract the
lazy_coherency optimisation our of the engine->get_seqno() vfunc into
its own callback.

v2: Rename the barrier to engine->irq_seqno_barrier to try and better
reflect that the barrier is only required after the user interrupt before
reading the seqno (to ensure that the seqno update lands in time as we
do not have strict seqno-irq ordering on all platforms).

Reviewed-by: Dave Gordon <david.s.gordon@intel.com> [#v2]

v3: Comments for hangcheck paranoia. Mika wanted to keep the extra
barrier inside the hangcheck, just in case. I can argue that it doesn't
provide a barrier against anything, but the side-effects of applying the
barrier may prevent a false declaration of a hung GPU.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Dave Gordon <david.s.gordon@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460195877-20520-2-git-send-email-chris@chris-wilson.co.uk

In order to ensure seqno/irq coherency, we currently read a ring register.
The mmio transaction following the interrupt delays the inspection of
the seqno long enough for the MI_STORE_DWORD_IMM to update the CPU
cache. However, it is only the memory timing that is important for the
purposes of the delay, we do not need nor desire the extra forcewake.

v3: Update commentary
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com> [v2]
Link: http://patchwork.freedesktop.org/patch/msgid/1460195877-20520-1-git-send-email-chris@chris-wilson.co.uk

Currently for the case where there is enough space at the end of Ring
buffer for accommodating only the base request, the wrapround is done
immediately and as a result the base request gets added at the start
of Ring buffer. But there may not be enough free space at the beginning
to accommodate the base request, as before the wraparound, the wait was
effectively done for the reserved_size free space from the start of
Ring buffer. In such a case there is a potential of Ring buffer overflow,
the instructions at the head of Ring (ACTHD) can get overwritten.

Since the base request can fit in the remaining space, there is no need
to wraparound immediately. The wraparound will anyway happen later when
the reserved part starts getting used.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NAkash Goel <akash.goel@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1457688402-10411-1-git-send-email-akash.goel@intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org

Having fixed the tracking of the engine's last_submitted_seqno, we can
now rely on it for detecting when the engine is idle (and not have to
touch the requests pointer).

Testcase: igt/gem_exec_whisper
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460010558-10705-9-git-send-email-chris@chris-wilson.co.ukReviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>

Seal the request and mark it as pending execution before we submit it to
hardware. We assume that the actual submission cannot fail (that
guarantee is provided by preallocating space in the request for the
submission). As we may inspect this state without holding any locks
during hangcheck we should apply a barrier to ensure that we do
not see a more recent value in the HWS than we are tracking.

Based on a patch by Mika Kuoppala.
Suggested-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460010558-10705-8-git-send-email-chris@chris-wilson.co.ukReviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>

When we change the current seqno, we also need to remember to reset the
last_submitted_seqno for the engine.

Testcase: igt/gem_exec_whisper
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460010558-10705-7-git-send-email-chris@chris-wilson.co.uk

An oversight is that when we wrap the seqno, we need to reset the hw
semaphore counters to 0. We did this for gen6 and gen7 and forgot to do
so for the new implementation required for gen8 (legacy).
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460010558-10705-6-git-send-email-chris@chris-wilson.co.uk

We reuse the same calculation into two macros, and I want to add a third
user. Time to refactor.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460010558-10705-5-git-send-email-chris@chris-wilson.co.uk

Since we are setting engine local values that are tied to the hardware,
move it out of i915_gem_init_seqno() into the intel_ring_init_seqno()
backend, next to where the other hw semaphore registers are written.

v2: Make the explanatory comment about always resetting the semaphores to
0 irrespective of the value of the reset seqno.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460010558-10705-4-git-send-email-chris@chris-wilson.co.uk

We only use drm_i915_private within the function, so delete the unneeded
drm_device local.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460010558-10705-3-git-send-email-chris@chris-wilson.co.uk

After the GPU reset and we discard all of the incomplete requests, mark
the GPU as having advanced to the last_submitted_seqno (as having
completed the requests and ready for fresh work). The impact of this is
negligible, as all the requests will be considered completed by this
point, it just brings the HWS into line with expectations for external
viewers.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460010558-10705-2-git-send-email-chris@chris-wilson.co.uk

It's useful to look at the last seqno submitted on a particular engine
and compare it against the HWS value to check for irregularities.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460010558-10705-1-git-send-email-chris@chris-wilson.co.uk

At BXT DSI, PIPE registers are inactive. So we can't get the
PIPE's mode parameters from them. The possible option is
retriving them from the PORT registers.

The required changes are added for BXT in intel_dsi_get_config
(encoder->get_config).

v2: Addressed the Jani's comments
    -removed the redundant call to encoder->get_config
    -read bpp from port register
    -removed retrival of src_size from encoder->get_config

v3: pipe_config->pipe_bpp is fixed
    Jani's review comments addressed:
	Few horizontal timing parameters dropped from the patch to make
	progress, as there seems to be some disagreement on
	best/feasible/possible options.
Signed-off-by: NRamalingam C <ramalingam.c@intel.com>
Signed-off-by: NUma Shankar <uma.shankar@intel.com>

Previously Reviewed at: https://lists.freedesktop.org/archives/intel-gfx/2016-April/091737.htmlSigned-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460019967-26501-2-git-send-email-ramalingam.c@intel.com

Shared the function pixel_format_from_vbt for whole display module.
Function declaration is added to intel_dsi.h.

V2: Moved the function to intel_dsi.c and renamed as per the purpose
	of the function. Suggested by Jani.
Signed-off-by: NRamalingam C <ramalingam.c@intel.com>

Previously reviewed at https://lists.freedesktop.org/archives/intel-gfx/2016-April/091736.htmlSigned-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460019967-26501-1-git-send-email-ramalingam.c@intel.com

The shorthand is easier. Also change the struct name. No functional
changes.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/6572c108424a67b02367ea69cbbe00a03af9b958.1459884518.git.jani.nikula@intel.com

Prepare for future. No functional changes.

v2: Move earlier in the series. Use bool for gpio value.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
[Jani: restored fixme comment while applying.]
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/ee791fed271d7f31c34163de6c6be37d1b704ef3.1459884518.git.jani.nikula@intel.com

Define and store the pad base offset in the array, and reference the
pconf0 and padval registers through macros. Add VLV prefixes to
macros. Use spec nomenclature for pconf0 and padval.

v2: Address Ville's review comments, squash another patch here.

v3: Use the names Ville dug up in the specs.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/34932140b78a3de7f825c78380a08c930694651b.1459884518.git.jani.nikula@intel.com

dev_priv is what the macro works hard to extract, pass it directly.

> sed 's/\([A-Z].*(dev_priv\)->dev)/\1)/g'

v2:
- Include all wrapper macros too (Chris)

v3:
- Include sed cmdline (Chris)

v4:
- Break long line
- Rebase

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460016485-8089-1-git-send-email-joonas.lahtinen@linux.intel.com

According to Chris, use of i915_vm_to_ppgtt is visible in benchmark
unless WARN_ON is removed, so lets get rid of it.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reported-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v1)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

Looks much better without container_of everywhere.

v2:
- In i915_gem_restore_gtt_mappings too (Chris)

v3:
- Do not cause WARN by calling on non PPGTT object (Chris)

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

intel_update_max_cdclk() doesn't have a switch case for Broxton, so
dev_priv->max_cdclk_freq gets set to whatever clock frequency we're
currently running at (e.g., 144 MHz) rather than the true maximum.  This
causes our max dotclock to also be set too low and in turn leads mode
verification to reject perfectly valid modes while loading EDID firmware
blobs.

Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459892239-14041-1-git-send-email-matthew.d.roper@intel.com

Use plane size for relative data rate calculation. don't always use
pipe source width & height.
adjust height & width according to rotation.
use plane size for watermark calculations also.

v2: Address Matt's comments.
    Use intel_plane_state->visible to avoid divide-by-zero error.
    Where FB was present but not visible so causing total data rate to
    be zero, hence divide-by-zero.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93917
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94044
Cc: drm-intel-fixes@lists.freedesktop.org
Signed-off-by: NKumar, Mahesh <mahesh1.kumar@intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459956399-1296-1-git-send-email-matthew.d.roper@intel.com

This patch sets the invert bit for hpd detection for each port
based on VBT configuration. Since each AOB can be designed to
depend on invert bit or not, it is expected if an AOB requires
invert bit, the user will set respective bit in VBT.

v2: Separated VBT parsing from the rest of the logic. (Jani)

v3: Moved setting invert bit logic to bxt_hpd_irq_setup()
    and changed its logic to avoid looping twice. (Ville)

v4: Changed the logic to mask out the bits first and then
    set them to remove need of temporary variable. (Ville)

v5: Moved defines to existing set of defines for the register
    and added required breaks. (Ville)
Signed-off-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Signed-off-by: NDurgadoss R <durgadoss.r@intel.com>
Signed-off-by: NShubhangi Shrivastava <shubhangi.shrivastava@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
[Jani: fixed some checkpatch noise, added kernel-doc.]
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459420907-11383-2-git-send-email-shubhangi.shrivastava@intel.com

This patch adds new fields that are not yet added in drm code
in child devices struct
Signed-off-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Signed-off-by: NDurgadoss R <durgadoss.r@intel.com>
Signed-off-by: NShubhangi Shrivastava <shubhangi.shrivastava@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459420907-11383-1-git-send-email-shubhangi.shrivastava@intel.com

Currently we set the initial GPU frequency to min_freq_softlimit
on gen9, and to efficient_freq on VLV/CHV. On all the other platforms
we set it to idle_freq. Let's use idle_freq across the board to make
sure we don't waste power. This is especially relevant for VLV since
Vnn won't drop to minimum unless the GPU is at the minimum frequency.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1457120584-26080-3-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

Extract the GPLL reference frequency from CCK and use it in the
GPU freq<->opcode conversions on VLV/CHV. This eliminates all the
assumptions we have about which divider is used for which czclk
frequency.

Note that unlike most clocks from CCK, the GPLL ref clock is a divided
down version of the CZ clock rather than the HPLL clock. CZ clock itself
is a divided down version of the HPLL clock though, so in effect it just
gets divided down twice.

While at it, throw in a few comments explaining the remaining constants
for anyone who later wants to compare this to the spreadsheets.

v2: Add slow/fast notes for CHV clocks (Imre)
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1457120584-26080-2-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Imre Deak <imre.deak@intel.com> (v1)

After a suspend-resume cycle, the resumed kernel has no idea what the
booted kernel may have done to the GuC before replacing itself with the
resumed image. In particular, it may have already loaded the GuC with
firmware, which will then cause this kernel's attempt to (re)load the
firmware to fail (GuC program memory is write-once!). The symptoms
(GuC firmware reload fails after hibernation) are further described
in the Bugzilla reference below.

So let's *always* reset the GuC just before (re)loading the firmware;
the hardware should then be in a well-known state, and we may even
avoid some of the issues arising from unpredictable timing.

Also added some more fields & values to the definition of the GUC_STATUS
register, which is the key diagnostic indicator if the GuC load fails.
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Cc: Alex Dai <yu.dai@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94390Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

Due to timing issues in the HW, some of the status bits required for GuC
authentication occasionally don't get set; when that happens, the GuC
cannot be initialized and we will be left with a wedged GPU. The W/A
suggested is to perform a soft reset of the GuC and attempt to reload
the F/W again for few times before giving up.

As the failure is dependent on timing, tests performed by triggering
manual full gpu reset (i915_wedged) showed that we could sometimes hit
this after several thousand iterations, but sometimes tests ran even
longer without any issues. Reset and reload mechanism proved helpful
when we indeed hit f/w load failure, so it is better to include this
to improve driver stability.

This change implements the following WAs,

	WaEnableuKernelHeaderValidFix:skl,bxt
	WaEnableGuCBootHashCheckNotSet:skl,bxt
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NAlex Dai <yu.dai@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

Both the oom and vmap notifier callbacks have a loop to acquire the
struct_mutex and set the device as uninterruptible, within a certain
time. Refactor the common code into a pair of functions.
Suggested-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459848145-24042-1-git-send-email-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

If the core runs out of vmap address space, it will call a notifier in
case any driver can reap some of its vmaps. As i915.ko is possibily
holding onto vmap address space that could be recovered, hook into the
notifier chain and try and reap objects holding onto vmaps.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Roman Pen <r.peniaev@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kahola <mika.kahola@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459777603-23618-4-git-send-email-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

vmaps are temporary kernel mappings that may be of long duration.
Reusing a vmap on an object is preferrable for a driver as the cost of
setting up the vmap can otherwise dominate the operation on the object.
However, the vmap address space is rather limited on 32bit systems and
so we add a notification for vmap pressure in order for the driver to
release any cached vmappings.

The interface is styled after the oom-notifier where the callees are
passed a pointer to an unsigned long counter for them to indicate if they
have freed any space.

v2: Guard the blocking notifier call with gfpflags_allow_blocking()
v3: Correct typo in forward declaration and move to head of file
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Roman Peniaev <r.peniaev@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Andrew Morton <akpm@linux-foundation.org> # for inclusion via DRM
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459777603-23618-3-git-send-email-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

Since we only attempt to purge an object if can_release_pages() report
true, we should also only add it to the count of potential recoverable
pages when can_release_pages() is true.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Akash Goel <akash.goel@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459777603-23618-2-git-send-email-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/65d58c578adecc205a741102329bc9c9f6eb79cf.1458299160.git.jani.nikula@intel.com