On Apollolake, with stress test warm reboot, audio card was not getting
enumerated after reboot. This was a spurious issue happening on
Apollolake. HW codec and HD audio controller link was going out of sync
for which there was a fix in i915 driver but was not getting invoked for
BXT. Extending this fix to BXT as well.

Tested on apollolake chromebook by stress test warm reboot with 2500
iterations.

Bspec: 21829
Signed-off-by: NGaurav K Singh <gaurav.k.singh@intel.com>
Reviewed-by: NDhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1522946544-11524-1-git-send-email-gaurav.k.singh@intel.com

Static code analysis tool reported memory leak in
intel_hdcp_auth_downstream. Fixing the memory leak.

v2: Rebase, move free to a cleanup label(Jani)

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Signed-off-by: NRadhakrishna Sripada <radhakrishna.sripada@intel.com>
Reviewed-by: NAnusha Srivatsa <anusha.srivatsa@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180404225957.7457-1-radhakrishna.sripada@intel.com

If we skip the intel_prepare_reset(), we should also skip the
intel_display_reset(). If we we use a flag set by intel_prepare_reset()
then we do not have to second guess based on external user controlled
state whether or not the prepare was called before deciding to finish
it after the reset. igt/gem_eio is one such example that may tweak
i915.reset faster than the code is expecting, leading to

[  190.233528] =====================================
[  190.233534] WARNING: bad unlock balance detected!
[  190.233540] 4.16.0-rc7-g335ef9849310-drmtip_10+ #1 Tainted: G     U
[  190.233547] -------------------------------------
[  190.233553] gem_eio/1348 is trying to release lock (crtc_ww_class_acquire) at:
[  190.233569] [<ffffffff895c7810>] drm_modeset_acquire_fini+0x0/0x60
[  190.233575] but there are no more locks to release!
[  190.233580]
               other info that might help us debug this:
[  190.233588] 3 locks held by gem_eio/1348:
[  190.233592]  #0:  (&f->f_pos_lock){+.+.}, at: [<00000000ab90c784>] __fdget_pos+0x3a/0x50
[  190.233607]  #1:  (sb_writers#11){.+.+}, at: [<00000000e1529265>] vfs_write+0x188/0x1a0
[  190.233622]  #2:  (&attr->mutex){+.+.}, at: [<0000000011f40afe>] simple_attr_write+0x36/0xd0
[  190.233635]
               stack backtrace:
[  190.233644] CPU: 0 PID: 1348 Comm: gem_eio Tainted: G     U           4.16.0-rc7-g335ef9849310-drmtip_10+ #1
[  190.233655] Hardware name: Dell Inc.                 OptiPlex GX280               /0G8310, BIOS A04 02/09/2005
[  190.233664] Call Trace:
[  190.233674]  dump_stack+0x67/0x95
[  190.233682]  ? drm_modeset_backoff+0x1b0/0x1b0
[  190.233690]  print_unlock_imbalance_bug+0xd2/0xe0
[  190.233698]  ? drm_modeset_backoff+0x1b0/0x1b0
[  190.233704]  lock_release+0x23e/0x300
[  190.233712]  drm_modeset_acquire_fini+0x16/0x60
[  190.233835]  intel_finish_reset+0x72/0x160 [i915]
[  190.233894]  i915_reset_device+0x1e9/0x240 [i915]
[  190.233953]  ? __intel_get_crtc_scanline+0x1c0/0x1c0 [i915]
[  190.233962]  ? work_on_cpu_safe+0x50/0x50
[  190.234020]  i915_handle_error+0x1f2/0x470 [i915]
[  190.234031]  ? __might_fault+0x39/0x90
[  190.234037]  ? __might_fault+0x39/0x90
[  190.234099]  i915_wedged_set+0x7f/0xc0 [i915]
[  190.234107]  simple_attr_write+0xb0/0xd0
[  190.234117]  full_proxy_write+0x51/0x80
[  190.234125]  __vfs_write+0x21/0x140
[  190.234133]  ? rcu_read_lock_sched_held+0x6f/0x80
[  190.234140]  ? rcu_sync_lockdep_assert+0x29/0x50
[  190.234147]  ? __sb_start_write+0x152/0x1f0
[  190.234152]  ? __sb_start_write+0x168/0x1f0
[  190.234159]  vfs_write+0xbd/0x1a0
[  190.234166]  SyS_write+0x40/0xa0
[  190.234173]  ? do_syscall_64+0x19/0x1b0
[  190.234180]  do_syscall_64+0x6b/0x1b0
[  190.234188]  entry_SYSCALL_64_after_hwframe+0x42/0xb7
[  190.234196] RIP: 0033:0x7f84c1b392b7
[  190.234201] RSP: 002b:00007f84b6755b00 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
[  190.234211] RAX: ffffffffffffffda RBX: 0000000000000046 RCX: 00007f84c1b392b7
[  190.234218] RDX: 0000000000000002 RSI: 000055ec20abc8d6 RDI: 0000000000000046
[  190.234225] RBP: 000055ec20abc8d6 R08: 0000000000000000 R09: 0000000000000000
[  190.234231] R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002
[  190.234238] R13: 0000000000000000 R14: 00007f84b0000b20 R15: 000055ec20ce4eb8

Testcase: igt/gem_eio
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180405123714.3638-1-chris@chris-wilson.co.uk

Before adding a new feature to execlists submission, we should endeavour
to cover the baseline behaviour with selftests. So start the ball
rolling.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiarski@intel.com>
CC: Michel Thierry <michel.thierry@intel.com>
Cc: Jeff McGee <jeff.mcgee@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180404093329.5383-1-chris@chris-wilson.co.uk

Along the eb_lookup_vmas() error path, the return value from
kmem_cache_alloc() was freed using kfree(). Fix it to use the proper
kmem_cache_free() instead.

Fixes: d1b48c1e ("drm/i915: Replace execbuf vma ht with an idr")
Signed-off-by: NXidong Wang <wangxidong_97@163.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: <stable@vger.kernel.org> # v4.14+
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180404093824.9313-1-chris@chris-wilson.co.uk

HDCP1.4 key can be loaded, only when Power well #1 is enabled and cdclk
is enabled. Using the I915 power well infrastruture, above requirement
is verified.

This patch enables the hdcp initialization for HSW, BDW, and BXT.

v2:
  Choose the PW# based on the platform.
v3:
  No Changes.
Signed-off-by: NRamalingam C <ramalingam.c@intel.com>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1522663834-24482-4-git-send-email-ramalingam.c@intel.com

In case of V prime mismatch, DP HDCP spec mandates the re-read of
Vprime atleast twice.

This patch needed for DP HDCP1.4 CTS Test: 1B-05.

v2:
  Moved the V' validation into a function for retry. [Sean Paul]
v3:
  Removed Inline keyword and DRM_DEBUG_KMS are used [Sean Paul]
Signed-off-by: NRamalingam C <ramalingam.c@intel.com>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1522663834-24482-3-git-send-email-ramalingam.c@intel.com

As per DP spec when R0 mismatch is detected, HDCP source supported
re-read the R0 atleast twice.

And For HDMI and DP minimum wait required for the R0 availability is
100mSec. So this patch changes the wait time to 100mSec but retries
twice with the time interval of 100mSec for each attempt.

This patch is needed for DP HDCP1.4 CTS Test: 1A-06.

v2:
  No Change
v3:
  Comment on R0 retry is moved closer to the code[Seanpaul]
v4:
  Removing unwanted noise introduced in v3.
Signed-off-by: NRamalingam C <ramalingam.c@intel.com>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1522669822-2508-1-git-send-email-ramalingam.c@intel.com

Let's avoid having to delve down the pointer chain to see if the i915
device has support for preemption and store that on the engine, which
made the decision in the first place!

v2: Refactor common preemption policy between execlists/guc.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tomasz Lis <tomasz.lis@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180403183537.5522-1-chris@chris-wilson.co.uk

We would like to start doing some bookkeeping at the beginning, between
contexts and at the end of execlists submission. We already mark the
beginning and end using EXECLISTS_ACTIVE_USER, to provide an indication
when the HW is idle. This give us a pair of sequence points we can then
expand on for further bookkeeping.

v2: Refactor guc submission to share the same begin/end.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Francisco Jerez <currojerez@riseup.net>
Reviewed-by: NFrancisco Jerez <currojerez@riseup.net>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180331130626.10712-1-chris@chris-wilson.co.uk

Commit 'aee3bac0 ("drm/i915/psr: Tie PSR2 support to Y
coordinate requirement")' got merged to drm-intel-next-queued
but the variable was defined commit 'c5fe4732 ("drm: Add PSR
version 3 macro") who was merged through drm-misc.

So backmerging to get drm-intel-next-queued compiling back again.
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>

In the 2 eDP1.4a pannels tested set or not set bit have no effect
but is better set it and comply with specification.
Signed-off-by: NJosé Roberto de Souza <jose.souza@intel.com>
Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180328223046.16125-9-jose.souza@intel.com

This value do not change overtime so better cache it than
fetch it every PSR enable.

Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NJosé Roberto de Souza <jose.souza@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180328223046.16125-8-jose.souza@intel.com

Cosmetic change.
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NJosé Roberto de Souza <jose.souza@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180328223046.16125-7-jose.souza@intel.com

Sink can support our PSR2 requirements but userspace can request
a resolution that PSR2 hardware do not support, in this case it
was overwritten the PSR2 sink support.
Adding another flag here, this way if requested resolution changed
to a value that PSR2 hardware can handle, PSR2 can be enabled.

Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NJosé Roberto de Souza <jose.souza@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180328223046.16125-6-jose.souza@intel.com

For Geminilake and Cannonlake+ the Y-coordinate support must be
enabled in PSR2_CTL too.

Spec: 7713 and 7720

Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NJosé Roberto de Souza <jose.souza@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180328223046.16125-5-jose.souza@intel.com

Although i915 don't implement aux sync frame through tests was
findout that pannels can do selective update when the y-coordinate
is also included in SDP, that is why it is required to run PSR2 in
i915.

So moving to only one place the sink requirements that the actual
driver needs to enable PSR2.

Also intel_psr2_config_valid() is called every time the crtc config
is computed, wasting some time every time it was checking for
Y coordinate requirement.

This allow us to nuke y_cord_support and some of VSC setup code that
was handling a scenario that would never happen(PSR2 without Y
coordinate).

Also here renaming intel_dp_get_y_cord_status() to
intel_dp_get_y_coord_required() as it more accurate to the name and
function of bit according to eDP spec.

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NDhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: NJosé Roberto de Souza <jose.souza@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180328223046.16125-4-jose.souza@intel.com

eDP spec states that aux frame is required to do PSR2 selective
update but i915 don't fully implement it. It sends the aux frame
sync messages but the value is always zero as the GTC is not enabled
in driver.

Through tests was findout that pannels can do selective update when
the y-coordinate is also included in SDP, that is why it is required
to run PSR2 in i915.

A dummy value is not useful at all to sink, so removing everything
related to aux frame sync, if GTC is enabled we can bring this back.

Cc: Vathsala Nagaraju <vathsala.nagaraju@intel.com>
Acked-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NDhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: NJosé Roberto de Souza <jose.souza@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180328223046.16125-3-jose.souza@intel.com

This is a register to help debug what is in the last SDP VSC
packet revived by sink.
Signed-off-by: NJosé Roberto de Souza <jose.souza@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180328223046.16125-2-jose.souza@intel.com

To comply with eDP1.4a this bit should be set when enabling PSR2.
Signed-off-by: NJosé Roberto de Souza <jose.souza@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180328223046.16125-1-jose.souza@intel.com

As intel_wait_for_register_fw() may use, and if successful only use, a
busy-wait loop, the might_sleep() warning is a little over-zealous.
Restrict it to a might_sleep_if() a slow timeout is specified (and so
the caller authorises use of a usleep).
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/20180329224519.13598-2-chris@chris-wilson.co.uk

Only sleep and repeat when asked for a full device reset (ALL_ENGINES)
and avoid using sleeping waits when asked for a per-engine reset. The
goal is to be able to use a per-engine reset from hardirq/softirq/timer
context. A consequence is that our individual wait timeouts are a
thousand times shorter, on the order of a hundred microseconds rather
than hundreds of millisecond. This may make hitting the timeouts more
common, but hopefully the fallover to the full-device reset will be
sufficient to pick up the pieces.

Note, that the sleeps inside older gen (pre-gen8) have been left as they
are only used in full device reset mode.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
CC: Michel Thierry <michel.thierry@intel.com>
Cc: Jeff McGee <jeff.mcgee@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180329224519.13598-1-chris@chris-wilson.co.uk

This will make it easier to spot issues related to config
creation/usage.
Signed-off-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180326090831.22686-9-lionel.g.landwerlin@intel.com

We had a generic field name used across 2 registers but it feels like
it's clearer we make it obvious what register this field belongs to.
Signed-off-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180326090831.22686-7-lionel.g.landwerlin@intel.com

This was added by mistake in commit 28964cf2 ("drm/i915/perf:
disable NOA logic when not used").
Signed-off-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180326090831.22686-6-lionel.g.landwerlin@intel.com

In commit d7965152 ("drm/i915: Enable i915 perf stream for
Haswell OA unit") the enable/disable vfunc hadn't appear yet and the
same function would deal with enabling/disabling the OA unit.

This was split later on for gen8 but the gen7 retained some code that
isn't actually useful anymore.
Signed-off-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180326090831.22686-4-lionel.g.landwerlin@intel.com

We've been a bit loose about this opening parameter. We should only
add the flag for writing OA reports when the value of this parameter
is != 0.
Signed-off-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180326090831.22686-3-lionel.g.landwerlin@intel.com

No significant changes from either context offsets, nor report
formats, nor register whitelist.

v2: Also drop slice/unslice clock ratio changes (Matt)
Signed-off-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180326133949.12469-3-lionel.g.landwerlin@intel.com

When we include a request's global_seqno in a GEM_TRACE it often helps
to know how that relates to the current breadcrumb as seen by the
hardware.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180327210157.16896-3-chris@chris-wilson.co.ukReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

Probably lost while rebasing commit eacd8391 ("drm/i915/guc: Keep GuC
interrupts enabled when using GuC").

Not really needed since i915_gem_init_hw is called before uc_resume, but
it brings symmetry to uc_suspend.
Signed-off-by: NMichel Thierry <michel.thierry@intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Reviewed-by: NMichał Winiarski <michal.winiarski@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180328205851.16188-1-michel.thierry@intel.com

- Mask mode type garbage from userspace (Ville)

Something went wrong on the misc tree side, but I'll pull the patch directly.

* 'drm-misc-next-fixes' of git://anongit.freedesktop.org/drm/drm-misc:
  drm: Fix uabi regression by allowing garbage mode->type from userspace

During debug we may want to investigate all communication
from the Guc. Add proper tracing macros in debug config.

v2: convert remaining DRM_DEBUG into new CT_DEBUG (Michal)
v3: use dedicated Kconfig (Daniele)
v4: checkpatch
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180326194829.58836-12-michal.wajdeczko@intel.com

When running on platform with CTB based GuC communication enabled,
GuC to Host event data will be delivered as CT request message.
However, content of the data[1] of this CT message follows format
of the scratch register used in MMIO based communication, so some
code reuse is still possible.

v2:  filter disabled messages (Daniele)
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Reviewed-by: Michel Thierry <michel.thierry@intel.com> #1
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Acked-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180327214124.70680-1-michal.wajdeczko@intel.com

Requests are read from CT in the irq handler, but actual processing
will be done in the work thread. Processing of specific actions will
be added in the upcoming patches.

v2: don't use GEM_BUG_ON (Chris)
    don't kmalloc too large buffer (Michal)
v3: rebased
v4: don't name it 'dispatch' (Michel) and fix checkpatch
    add some documentation (Michal)
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180326194829.58836-10-michal.wajdeczko@intel.com

Instead of returning small data in response status dword,
GuC may append longer data as response message payload.
If caller provides response buffer, we will copy received
data and use number of received data dwords as new success
return value. We will WARN if response from GuC does not
match caller expectation.

v2: fix timeout and checkpatch warnings (Michal)
v3: fix checkpatch again (Michel)
    update wait function name (Michal)
    no need for spinlock_irqsave (MichalWi)
    no magic numbers (MichalWi)
    must check before use (Jani)
    add some more documentation (Michal)
v4: update documentation (Michal)
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Michel Thierry <michel.thierry@intel.com> #2.5
Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180327121439.70096-1-michal.wajdeczko@intel.com

In next patch we will introduce another way of waiting for the response
that will use RECV buffer. To avoid misleading names, rename old wait
function to reflect the fact that it is based on descriptor update.

v2: fix comment style (Michal)
v3: use more specific name (Michel)
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180326194829.58836-8-michal.wajdeczko@intel.com

GuC can respond to our commands not only by updating SEND buffer
descriptor, but can also send a response message over RECV buffer.
Guc can also send unsolicited request messages over RECV buffer.
Let's start reading those messages and make placeholders
for actual response/request handlers.

v2: misc improvements (Michal)
v3: change response detection (Michal)
    invalid status is protocol error (Michal)
v4: rebase
v5: fix checkpatch (Michel)
    don't use fields before check (Jani)
    add some documentation (Michal)
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Michel Thierry <michel.thierry@intel.com> # 4.5
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180326194829.58836-7-michal.wajdeczko@intel.com

On platforms with CTB based GuC communications, we will handle
GuC events in a different way. Let's make event handler a virtual
function to allow easy switch between those variants.

Credits-to: Oscar Mateo <oscar.mateo@intel.com>
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180326194829.58836-6-michal.wajdeczko@intel.com

We're using data encoded in the status MMIO as return value from send
function, but GuC may also write more data in remaining MMIO regs.
Let's copy content of these registers to the buffer provided by caller.

v2: new line (Michel)
v3: updated commit message
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180326194829.58836-5-michal.wajdeczko@intel.com

This is a preparation step for the upcoming patches.
We already can return some small data decoded from the command
status, but we will need more in the future.

v2: add explicit response buf size
v3: squash with helper patch
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180326194829.58836-4-michal.wajdeczko@intel.com