Memory with 16GB dimms require an increase of 1us in level-0 latency.
This patch implements the same.
Bspec: 4381

changes since V1:
 - s/memdev_info/dram_info
 - make skl_is_16gb_dimm pure function
Changes since V2:
 - make is_16gb_dimm more generic
 - rebase
Changes since V3:
 - Simplify condition (Maarten)
Signed-off-by: NMahesh Kumar <mahesh1.kumar@intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180831110942.9234-1-mahesh1.kumar@intel.com

This patch adds support to decode system memory bandwidth and other
parameters for skylake and Gen9+ platforms, which will be used for
arbitrated display memory bandwidth calculation in GEN9 based
platforms and WM latency level-0 Work-around calculation on GEN9+.

Changes Since V1:
 - s/memdev_info/dram_info
 - create a struct to hold channel info
Changes Since V2:
 - rewrite code to adhere i915 coding style
 - not valid for GLK
Signed-off-by: NMahesh Kumar <mahesh1.kumar@intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180824093225.12598-3-mahesh1.kumar@intel.com

This patch adds support to decode system memory bandwidth and other
parameters for broxton platform, which will be used for arbitrated
display memory bandwidth calculation in GEN9 based platforms and
WM latency level-0 Work-around calculation on GEN9+ platforms.

Changes since V1:
 - s/memdev_info/dram_info
Changes since V2:
 - Adhere to i915 coding style (Rodrigo)
Signed-off-by: NMahesh Kumar <mahesh1.kumar@intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180824093225.12598-2-mahesh1.kumar@intel.com

Add Support to load DMC on Icelake.

While at it, also add support to load the firmware
during system resume.

v2: load firmware during system resume.(Imre)

v3: enable has_csr for icelake.(Jyoti)

v4: Only load the firmware in this patch

Cc: Jyoti Yadav <jyoti.r.yadav@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NAnusha Srivatsa <anusha.srivatsa@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180828003844.4682-2-anusha.srivatsa@intel.com

If we have framebuffers that are >= 4GiB in size we will overflow
the fb size check in intel_fill_fb_info().

Currently that is only possible with NV12 and CCS as offsets[1]
may be anything between 0 and 0xffffffff. offsets[0] is currently
required to be 0 so we can't hit the overflow with any single
plane format (thanks to max fb size of 8kx8k and max stride of
32 KiB).

In the future we may allow almost any framebuffer to exceed 4GiB
in size so we really should fix the overflow. Not that the overflow
is particularly dangerous. It's mostly just a sanity check against
insane userspace. The display engine can't write to memory anyway
so I suppose in the worst case we might anger the hw by attempting
scanout past the end of the ggtt, or we might scan out some data
that we're not supposed to see from other parts of the ggtt.

Note that triggering this overflow depends on the driver
aligning the fb height to the next tile boundary to push the
calculated size above 4GiB. With linear buffers the effective
tile height is one so that never happens, and the core already
has a check for 32bit overflow of offsets[]+pitches[]*height.

v2: Drop the unnecessary cast (Chris)

Testcase: igt/kms_big_fb/x-tiled-addfb-size-offset-overflow
Testcase: igt/kms_big_fb/y-tiled-addfb-size-offset-overflow
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180912180443.28649-1-ville.syrjala@linux.intel.com

Use I915_GTT_PAGE_SIZE when talking about GTT pages rather than
physical pages.

There are some PAGE_SHIFTs left though. Not sure if we want to
introduce I915_GTT_PAGE_SHIFT or what?

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Suggested-by: Chris Wilson <chris@chris-wilson.co.uk> # at least some of it :)
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180913150405.706-1-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

We can remove the update-via-batch-buffer code path, which is basically an
effective duplicate of update-via-context-image path, if we notice that
after we have idled the GPU, we can update the context image even of the
kernel context directly. (Update-via-batch-buffer path existed only to
solve the problem of how to update the kernel context image.)

Only additional thing needed is to activate the edited configuration by
sending one empty request down the pipe. This accomplishes context restore
of the updated kernel context and so the OA configuration gets written out
to it's control registers.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180912152930.28237-1-tvrtko.ursulin@linux.intel.com

Extract intel_cursor_check_surface() to better match the code layout
of the other plane types.
Reviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907152413.15761-14-ville.syrjala@linux.intel.com

Move the chv rotation vs. reflections checks to the plane->check() hook,
away from the (now) platform agnostic
intel_plane_atomic_check_with_state().
Reviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907152413.15761-13-ville.syrjala@linux.intel.com

Move the display w/a #1175 to a better place. That place
being the new skl+ specific plane->check() hook. This leaves
the skl_check_plane_surface() stuff to deal with the gtt offset
and src coordinate stuff as originally envisioned.
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907152413.15761-12-ville.syrjala@linux.intel.com

Move the skl+ specific framebuffer related checks from
intel_plane_atomic_check_with_state() into a new function
(skl_plane_check_fb()) which we'll simply call from the skl
plane->check() hook.

v2: Split out the Y/Yf+CCS vs. interlaced change (José)
Reviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907152413.15761-11-ville.syrjala@linux.intel.com

Split up intel_check_primary_plane() and intel_check_sprite_plane()
into per-platform variants. This way we can get a unified behaviour
between the SKL universal planes, and we stop checking for non-SKL
specific scaling limits for the "sprite" planes. And we now get
a natural place where to add more plarform specific checks.

v2: Split the .check_plane() calling convention change out (José)
Reviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907152413.15761-10-ville.syrjala@linux.intel.com

We can easily calculate the plane can_scale/min_downscale on demand.
And later on we'll probably want to start calculating these dynamically
based on the cdclk just as skl already does.
Reviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907152413.15761-9-ville.syrjala@linux.intel.com

To reduce the confusion between a drm plane and the planes of
framebuffers let's desiginate the latter as "color plane".
Weak-Reviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907152413.15761-8-ville.syrjala@linux.intel.com

Stash the gtt_view structure into the plane state. This will become
useful when we do GTT remapping as the gtt_view will not come directly
from the fb anymore.
Reviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907152413.15761-7-ville.syrjala@linux.intel.com

Let's store the final plane stride in the plane state. This avoids
having to pick between the normal vs. rotated stride during hardware
programming. And once we get GTT remapping the plane stride will
no longer match the fb stride so we'll need a place to store it
anyway.

v2: Keep checking fb->pitches[0] for cursor as later on we won't
    populate plane_state->color_plane[0].stride for invisible planes
    and we have been checking the cursor fb stride even for invisible
    planes
v3: s/betwen/between in commit msg (José)
v4: Check color_plane[0].stride instead of fb->pitches[0] in
    the skl_check_main_surface() X-tiling kludge
Reviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180911150139.23922-1-ville.syrjala@linux.intel.com

Make the main/aux surface stuff a bit more generic by using an array
of structures. This will allow us to deal with both the main and aux
surfaces with common code.
Reviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907152413.15761-5-ville.syrjala@linux.intel.com

Let's assume that the primary plane for pipe A has the highest max
stride of all planes, and we'll use that as the global limit when
creating a new framebuffer.
Reviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907152413.15761-4-ville.syrjala@linux.intel.com

Each plane may have different stride limitations. Let's add a new
plane function to retutn the maximum stride for each plane. There's
going to be some use for this outside the .atomic_check() stuff hence
the separate hook.

v2: Fix ilk+ x-tiled max stride to be 32k (José)
Reviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907152413.15761-3-ville.syrjala@linux.intel.com

Rename some of the tile_offset() functions to aligned_offset() since
they operate on both linear and tiled functions. And we'll include
_plane_ in the name of all the variants that take a plane state.
Should make it more clear which function to use where.

v2: Pimp the patch subject a bit (José)
Reviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907152413.15761-2-ville.syrjala@linux.intel.com

If the caller supplies more than 4G of objects and than one that has to
be in the low 4G, it is possible for the low 4G to be full before we
attempt to find room for the last object that must be there. As we don't
reorder the two types, every pass hits the same problem and we fail with
ENOSPC. However, if we impose a little bit of ordering between the two
classes of objects, on the second pass we will be able to fit the
special object as we do it first. For setups that only use !48b objects,
we now reverse the order between passes, hopefully making the subsequent
passes more likely to succeed given that we are trying a different
order (rather than repeating the previous pass!)

v2: Quick one line explanation for the relative priorities given to
reservations.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180912101133.31377-1-chris@chris-wilson.co.uk

Baytrail takes a little more convincing that it needs to actually reload
its Page Directoy (ppGTT) before the context switch, so repeat it until
it gets the message. Once again the arbitrary values here are
empirically derived.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107861
Testcase: igt/gem_exec_parallel/fds
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180910130808.10809-1-chris@chris-wilson.co.uk

Userspace should be free to race against itself and shoot itself in
the foot if it so desires to adjust a parameter at the same time as
submitting a batch to that context. As such, the struct_mutex in context
setparam is only being used to serialise userspace against itself and
not for any protection of internal structs and so is superfluous.

v2: Separate user_flags from internal flags to reduce chance of
interference; and use locked bit ops for user updates.
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/20180911132206.23032-1-chris@chris-wilson.co.uk

This patch defines DSI_T_INIT_MASTER register for DSI ports
0/1 which will be used in dphy programming.
Signed-off-by: NMadhav Chauhan <madhav.chauhan@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1531215614-6828-5-git-send-email-madhav.chauhan@intel.com

The user parameters to put_image are not copied back to userspace
(DRM_IOW), and so we can modify the ioctl parameters (having already been
copied to a temporary kernel struct) directly and use those in place,
avoiding another temporary malloc and lots of manual copying.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180906190144.1272-2-chris@chris-wilson.co.uk

Given that we are now reasonably confident in our ability to detect and
reserve the stolen memory (physical memory reserved for graphics by the
BIOS) for ourselves on most machines, we can put it to use. In this
case, we need a page to hold the overlay registers.

On an i915g running MythTv, H Buus noticed that

	commit 6a2c4232
	Author: Chris Wilson <chris@chris-wilson.co.uk>
	Date:   Tue Nov 4 04:51:40 2014 -0800
	drm/i915: Make the physical object coherent with GTT

introduced stuttering into his video playback. After discarding the
likely suspect of it being the physical cursor updates, we were left
with the use of the phys object for the overlay. And lo, if we
completely avoid using the phys object (allocated just once on module
load!) by switching to stolen memory, the stuttering goes away.

For lack of a better explanation, claim victory and kill two birds with
one stone.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107600
Fixes: 6a2c4232 ("drm/i915: Make the physical object coherent with GTT")
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>
Link: https://patchwork.freedesktop.org/patch/msgid/20180906190144.1272-1-chris@chris-wilson.co.uk

During modeset, previously configured csc coefficient matrix,if any, will
not persist. This can result in blank screen as csc mode will be programmed
while loading LUT but csc coefficient matrix remains unprogrammed.

Changes since V1:
- Removed platform check
Signed-off-by: NP Raviraj Sitaram <raviraj.p.sitaram@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1536589634-29680-1-git-send-email-raviraj.p.sitaram@intel.com

We should update GuC power domain states also when GuC submission
is disabled, otherwise GuC might complain or ignore our requests.
This seems to be required for all currently released GuC firmwares.

v2: it is only needed by pre-Gen11 firmwares
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: John Spotswood <john.a.spotswood@intel.com>
Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Cc: Tomasz Lis <tomasz.lis@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: NAnusha Srivatsa <anusha.srivatsa@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180910104150.101752-1-michal.wajdeczko@intel.com

Using the guc, we cannot disable the user interrupt generation as we use
it for driving submission. And from Icelake, we no longer have the
ability to individually mask interrupt generation from each engine,
disabling our ability to fake missed interrupts.

In both cases, report back to userspace that the missed interrupt
generator is no longer available.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907112856.28242-1-chris@chris-wilson.co.uk

Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

gvt-next-2018-09-04

- guest context shadow optimization for restore inhibit one (Yan)
- cmd parser optimization (Yan)
- W=1 warning fixes (Zhenyu)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

# Conflicts:
#	drivers/gpu/drm/i915/gvt/reg.h
From: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180904030154.GG20737@zhen-hp.sh.intel.com

Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

Introduce a complementary function to i915_driver_create() to undo all
that is created.
Suggested-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180905140921.17467-2-chris@chris-wilson.co.uk

Attach our device_info to the our i915 private on creation so that it is
always available for inspection.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180905140921.17467-1-chris@chris-wilson.co.uk

During IPS disabling the current 42ms timeout value leads to occasional
timeouts, increase it to 100ms which seems to get rid of the problem.

References: https://bugs.freedesktop.org/show_bug.cgi?id=107494
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107562Reported-by: NDiego Viola <diego.viola@gmail.com>
Tested-by: NDiego Viola <diego.viola@gmail.com>
Cc: Diego Viola <diego.viola@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180905100005.7663-1-imre.deak@intel.com

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

If the previous modeset commit has completed and is no longer part of
the crtc state, skip waiting for it.

Ville pointed out that, in fact, the commit is never removed after a
modeset so the only way we could see a NULL here should be if there was
never a commit attached. Nevertheless, we have the evidence it can be
NULL and it has been defended against elsewhere, for example commit
93313538 ("drm/i915: Pass idle crtc_state to intel_dp_sink_crc").

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107792
Fixes: c44301fc ("drm/i915: Allow control of PSR at runtime through debugfs, v6")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180904162902.2578-1-chris@chris-wilson.co.uk

Elsewhere we manipulate uncore.unclaimed_mmio_check and
i915_param.mmio_debug under the irq lock (e.g. preserving the current
value across a user forcewake grab), but do not protect the manipulation
inside intel_uncore_arm_unclaimed_mmio_detection() from concurrent
access, even from itself. This is an issue as we do call
arm_unclaimed_mmio_detection from multiple threads without coordination.
Suggested-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intelcom>
Link: https://patchwork.freedesktop.org/patch/msgid/20180904131207.17563-1-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