With NV12 we have two color planes to deal with so we must compute the
surface and x/y offsets for the second plane as well.

What makes this a bit nasty is that the hardware expects the surface
offset to be specified as a distance from the main surface offset.
What's worse, the distance must be non-negative (no neat wraparound or
anything). So we must make sure that the main surface offset is always
less or equal to the AUX surface offset. We do that by computing the AUX
offset first and the main surface offset second. If the main surface
offset ends up being above the AUX offset, we just push it down as far
as is required while still maintaining the required alignment etc.

Fortunately the AUX offset only reuqires 4K alignment, so we don't need
to do any of the backwards searching for an acceptable offset that we
must do for the main surface. And X tiled + NV12 isn't a supported
combination anyway.

Note that this just computes aux surface offsets, we do not yet program
them into the actual hardware registers, and hence we can't yet expose
NV12.

v2: Rebase due to drm_plane_state src/dst rects
    s/TODO.../something else/ in the commit message/ (Daniel)
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470821001-25272-12-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

SKL has nasty limitations with the display surface offsets:
* source x offset + width must be less than the stride for X tiled
  surfaces or the display engine falls over
* the surface offset requires lots of alignment (256K or 1M)

These facts mean that we can't just pick any suitably aligned tile
boundary as the offset and expect the resulting x offset to be useable.
The solution is to start with the closest boundary as before, but then
keep searching backwards until we find one that works, or don't. This
means we must be prepared to fail, hence the whole surface offset
calculation needs to be moved to the .check_plane() hook from the
.update_plane() hook.

While at it we can check that the source width/height don't exceed
maximum plane size limits.

We'll store the results of the computation in the plane state to make
it easy for the .update_plane() hook to do its thing.

v2: Replace for+break loop with while loop
    Rebase due to drm_plane_state src/dst rects
    Rebase due to plane_check_state()
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470821001-25272-11-git-send-email-ville.syrjala@linux.intel.com

To make life less surprising we can make intel_adjust_tile_offset()
deal with linear buffers as well. Currently it doesn't seem like there's
a real need for this since only X tiling and NV12 (which would always
be tiled currently) should need it. But I've used it for some debug
hacks already so seems like a reasonable thing to have.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470821001-25272-10-git-send-email-ville.syrjala@linux.intel.com

Minimize the resulting X coordinate after intel_adjust_tile_offset() is
done with it's offset adjustment. This allows calling
intel_adjust_tile_offset() multiple times in case we need to adjust
the offset several times.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470821001-25272-9-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If there's a fence on the object it will be aligned to the start
of the object, and hence CPU rendering to any fb that straddles
the fence edge will come out wrong due to lines wrapping at the
wrong place.

We have no API to manage fences on a sub-object level, so we can't
really fix this in any way. Additonally gen2/3 fences are rather
coarse grained so adjusting the offset migth not even be possible.

Avoid these problems by requiring the fb layout to agree with the
fence layout (if present).

v2: Rebase due to i915_gem_object_get_tiling() & co.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470821001-25272-8-git-send-email-ville.syrjala@linux.intel.com

Currently we require the object to be X tiled if the fb is X
tiled. The argument is supposedly FBC GTT tracking. But
actually that no longer holds water since FBC supports
Y tiling as well on SKL+.

A better rule IMO is to require that if there is a fence, the
fb modifier match the object tiling mode. But if the object is linear,
we can allow the fb modifier to be anything. The idea being that
if the user set the tiling mode on the object, presumably the intention
is to actually use the fence for CPU access. But if the tiling mode is
not set, the user has no intention of using a fence (and can't actually
since we disallow tiling mode changes when there are framebuffers
associated with the object).

On gen2/3 we must keep to the rule that the object and fb
must be either both linear or both X tiled. No mixing allowed
since the display engine itself will use the fence if it's present.

v2: Fix typos
v3: Rebase due to i915_gem_object_get_tiling() & co.
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470821001-25272-7-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Soon the fence tiling mode may not always match the fb modifier
even for X tiled buffers. So let's use the fb modifier
consistently for all display tiling decisions.

v2: Rebased due to s/ring/engine/
v3: Rebased due to s/engine/ring/ O_o
v4: Rebase due to i915_gem_object_get_tiling() & co.

Reviewed-by: Matthew Auld <matthew.auld@intel.com> (v1)
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470821001-25272-6-git-send-email-ville.syrjala@linux.intel.com

intel_compute_tile_offset() and intel_add_fb_offsets() get passed the fb
and the rotation. As both of those come from the plane state we can just
pass that in instead.

For extra consitency pass the plane state to intel_fb_xy_to_linear() as
well even though it only really needs the fb.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470821001-25272-5-git-send-email-ville.syrjala@linux.intel.com

We repeat the SKL stride register value calculations a several places.
Move it into a small helper function.

v2: Rebase due to drm_plane_state src/dst rects
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Reviewed-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470821001-25272-4-git-send-email-ville.syrjala@linux.intel.com

intel_compute_page_offset() can dig up the correct pitch from the fb
itself, no need for the caller to pass it in.

A bit of extra care is needed for the lower level
_intel_compute_page_offset() since that one gets called before the
rotated pitch under intel_fb is populated. Note that we don't actually
call it with anything but DRM_ROTATE_0 there so we wouldn't actually
look up the rotated pitch there, but still, leave the pitch as something
the caller has to pass to _intel_compute_page_offset() as an
indicator that something is a bit special.

This leaves 'stride_div' in the skl plane update hooks as a mostly useless
variable so just get rid of it.

v2: Add a note why stride_div got nuked
v3: Extract intel_fb_pitch() since it can be useful later
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> (v2)
Reviewed-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470821001-25272-3-git-send-email-ville.syrjala@linux.intel.com

Redo the fb rotation handling in order to:
- eliminate the NV12 special casing
- handle fb->offsets[] properly
- make the rotation handling easier for the plane code

To achieve these goals we reduce intel_rotation_info to only contain
(for each plane) the rotated view width,height,stride in tile units,
and the page offset into the object where the plane starts. Each plane
is handled exactly the same way, no special casing for NV12 or other
formats. We then store the computed rotation_info under
intel_framebuffer so that we don't have to recompute it again.

To handle fb->offsets[] we treat them as a linear offsets and convert
them to x/y offsets from the start of the relevant GTT mapping (either
normal or rotated). We store the x/y offsets under intel_framebuffer,
and for some extra convenience we also store the rotated pitch (ie.
tile aligned plane height). So for each plane we have the normal
x/y offsets, rotated x/y offsets, and the rotated pitch. The normal
pitch is available already in fb->pitches[].

While we're gathering up all that extra information, we can also easily
compute the storage requirements for the framebuffer, so that we can
check that the object is big enough to hold it.

When it comes time to deal with the plane source coordinates, we first
rotate the clipped src coordinates to match the relevant GTT view
orientation, then add to them the fb x/y offsets. Next we compute
the aligned surface page offset, and as a result we're left with some
residual x/y offsets. Finally, if required by the hardware, we convert
the remaining x/y offsets into a linear offset.

For gen2/3 we simply skip computing the final page offset, and just
convert the src+fb x/y offsets directly into a linear offset since
that's what the hardware wants.

After this all platforms, incluing SKL+, compute these things in exactly
the same way (excluding alignemnt differences).

v2: Use BIT(DRM_ROTATE_270) instead of ROTATE_270 when rotating
    plane src coordinates
    Drop some spurious changes that got left behind during
    development
v3: Split out more changes to prep patches (Daniel)
    s/intel_fb->plane[].foo.bar/intel_fb->foo[].bar/ for brevity
    Rename intel_surf_gtt_offset to intel_fb_gtt_offset
    Kill the pointless 'plane' parameter from intel_fb_gtt_offset()
v4: Fix alignment vs. alignment-1 when calling
    _intel_compute_tile_offset() from intel_fill_fb_info()
    Pass the pitch in tiles in
    stad of pixels to intel_adjust_tile_offset() from intel_fill_fb_info()
    Pass the full width/height of the rotated area to
    drm_rect_rotate() for clarity
    Use u32 for more offsets
v5: Preserve the upper_32_bits()/lower_32_bits() handling for the
    fb ggtt offset (Sivakumar)
v6: Rebase due to drm_plane_state src/dst rects

Cc: Sivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NSivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470821001-25272-2-git-send-email-ville.syrjala@linux.intel.comAcked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Looks like the TSEG lives just above TOUD, stolen comes after TSEG.

The spec seems somewhat self-contradictory in places, in the ESMRAMC
register desctription it says:
 TSEG Size:
  10=(TOUD + 512 KB) to TOUD
  11 =(TOUD + 1 MB) to TOUD

so that agrees with TSEG being at TOUD. But the example given
elsehwere in the spec says:

 TOUD equals 62.5 MB = 03E7FFFFh
 TSEG selected as 512 KB in size,
 Graphics local memory selected as 1 MB in size
 General System RAM available in system = 62.5 MB
 General system RAM range00000000h to 03E7FFFFh
 TSEG address range03F80000h to 03FFFFFFh
 TSEG pre-allocated from03F80000h to 03FFFFFFh
 Graphics local memory pre-allocated from03E80000h to 03F7FFFFh

so here we have TSEG above stolen.

Real world evidence agrees with the TOUD->TSEG->stolen order however, so
let's fix up the code to account for the TSEG size.

Cc: Taketo Kabe <fdporg@vega.pgw.jp>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: stable@vger.kernel.org
Fixes: 0ad98c74 ("drm/i915: Determine the stolen memory base address on gen2")
Fixes: a4dff769 ("x86/gpu: Add Intel graphics stolen memory quirk for gen2 platforms")
Reported-by: NTaketo Kabe <fdporg@vega.pgw.jp>
Tested-by: NTaketo Kabe <fdporg@vega.pgw.jp>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96473Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470653919-27251-1-git-send-email-ville.syrjala@linux.intel.com
Link: http://download.intel.com/design/chipsets/datashts/25251405.pdfReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Currently to change the firmware one has to update the exported
module firmware string and the major-minor versions used for
verification after load. Consolidate that to a single place
defining correct major and minor versions per platform.

v2: Rebased for KBL.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Dave Gordon <david.s.gordon@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Peter Antoine <peter.antoine@intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470842206-35685-1-git-send-email-tvrtko.ursulin@linux.intel.com

Until now code was calling hweight32 to figure out the
number from device_info->ring_mask at runtime. Instead
we can cache it at engine init time and use directly.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1470842530-35854-1-git-send-email-tvrtko.ursulin@linux.intel.com

request->batch_obj is only set by execbuffer for the convenience of
debugging hangs. By moving that operation to the callsite, we can
simplify all other callers and future patches. We also move the
complications of reference handling of the request->batch_obj next to
where the active tracking is set up for the request.
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/1470832906-13972-2-git-send-email-chris@chris-wilson.co.uk

We allocate a few objects into the GGTT that we never need to access via
the mappable aperture (such as contexts, status pages). We can request
that these are bound high in the VM to increase the amount of mappable
aperture available. However, anything that may be frequently pinned
(such as logical contexts) we want to use the fast search & insert.
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/1470832906-13972-1-git-send-email-chris@chris-wilson.co.uk

During intel_gt_powersave_init() we take the RPS mutex to ensure that
all locking requirements are met as we talk to the punit, but we also
require the struct_mutex for allocating a slice of the global GTT for a
power context on Valleyview. struct_mutex must be the outer lock here,
as we nest rps.mutex inside later on.
Reported-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Fixes: 773ea9a8 ("drm/i915: Perform static RPS frequency setup before...")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470833904-29886-1-git-send-email-chris@chris-wilson.co.ukReviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

In the preceding patches we made sure that:
- the LVDS encoder takes care of reiniting both the LVDS register
and its PPS
- the eDP encoder takes care of reiniting its PPS
- the PPS register unlocking workaround is applied explicitly whenever
the PPS context is lost

Based on the above we can safely remove the opaque LVDS and PPS save /
restore from generic code.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470827254-21954-6-git-send-email-imre.deak@intel.com

Atm, we apply this workaround somewhat inconsistently at the following
points: driver loading, LVDS init, eDP PPS init, system resume. As this
workaround also affects registers other than PPS (timing, PLL) a more
consistent way is to apply it early after the PPS HW context is known to
be lost: driver loading, system resume and on VLV/CHV/BXT when turning
on power domains.

This is needed by the next patch that removes saving/restoring of the
PP_CONTROL register.

This also removes the incorrect programming of the workaround on HSW+
PCH platforms which don't have the register locking mechanism.

v2: (Ville)
- Don't apply the workaround on BXT.
- Simplify platform checks using HAS_DDI().
v3:
- Move the call of intel_pps_unlock_regs_wa() to the more
  logical vlv_display_power_well_init() (also fixing CHV) (Ville).
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470827254-21954-5-git-send-email-imre.deak@intel.com

Similarly to the previous patch, initialize the PPS from the DP
encoder's resume hook. Note that as opposed to LVDS we can't do this
during encoder enabling, since we need the PPS for DP detection as well.
The PPS init code is now the same for init and resume, so factor out a
new intel_dp_pps_init() helper for this.

v2:
- Factor out intel_dp_pps_init() (Ville).
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470827254-21954-4-git-send-email-imre.deak@intel.com

Atm the LVDS encoder depends on the PPS HW context being saved/restored
from generic suspend/resume code. Since the PPS is specific to the LVDS
and eDP encoders a cleaner way is to reinitialize it during encoder
enabling, so do this here for LVDS. Follow-up patches will init the PPS
for the eDP encoder similarly and remove the suspend/resume time save /
restore.

v2:
- Apply BSpec +1 offset and use DIV_ROUND_UP() when programming the
power cycle delay. (Ville)
v3: (Ville)
- Fix +1 vs. round-up order.
- s/reset_on_powerdown/powerdown_on_reset/
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470827254-21954-3-git-send-email-imre.deak@intel.com

These two flags mean the same thing, so remove the duplication.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470827254-21954-2-git-send-email-imre.deak@intel.com

The PPS registers are pretty much the same everywhere, the differences
being:
- Register fields appearing, disappearing from one platform to the
  next: panel-reset-on-powerdown, backlight-on, panel-port,
  register-unlock
- Different register base addresses
- Different number of PPS instances: 2 on VLV/CHV/BXT, 1 everywhere
  else.

We can merge the separate set of PPS definitions by extending the PPS
instance argument to all platforms and using instance 0 on platforms
with a single instance. This means we'll need to calculate the register
addresses dynamically based on the given platform and PPS instance.

v2:
- Simplify if ladder in intel_pps_get_registers(). (Ville)
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470827254-21954-1-git-send-email-imre.deak@intel.com

As we're tweaking the GuC-related code in debugfs, we can
drop the no-longer-used 'q_fail' and repack the structure.
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

Now that host structures are indexed by host engine-id rather than
guc_id, we can usefully convert some for_each_engine() loops to use
for_each_engine_id() and avoid multiple dereferences of engine->id.

Also a few related tweaks to cache structure members locally wherever
they're used more than once or twice, hopefully eliminating memory
references.
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

The Context Descriptor passed by the kernel to the GuC contains a field
specifying which engine(s) the context will use. Historically, this was
always set to "all of them", but if we had a separate client for each
engine, we could be more precise, and set only the bit for the engine
that the client was associated with. So this patch enables this usage,
in preparation for having multiple clients, though at this point there
is still only a single client used for all supported engines.
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

We have essentially the same code in each of two different
loops, so we can refactor it into a little helper function.

This also reduces the amount of work done during startup,
as we now only reprogram h/w found to be in a state other
than that expected, and so avoid the overhead of setting
doorbell registers to the state they're already in.
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

guc_init_doorbell_hw() borrows the (currently single) GuC client to use
in reinitialising ALL the doorbell registers (as the hardware doesn't
reset them when the GuC is reset). As a prerequisite for accommodating
multiple clients, it should only reset doorbells that are supposed to be
disabled, avoiding those that are marked as in use by any client.
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

The bottom-half we use for processing the breadcrumb interrupt is a
task, which is an RCU protected struct. When accessing this struct, we
need to be holding the RCU read lock to prevent it disappearing beneath
us. We can use the RCU annotation to mark our irq_seqno_bh pointer as
being under RCU guard and then use the RCU accessors to both provide
correct ordering of access through the pointer.

Most notably, this fixes the access from hard irq context to use the RCU
read lock, which both Daniel and Tvrtko complained about.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1470761272-1245-3-git-send-email-chris@chris-wilson.co.uk

In commit 2529d570 ("drm/i915: Drop racy markup of missed-irqs from
idle-worker") the racy detection of missed interrupts was removed when
we went idle. This however opened up the issue that the stuck waiters
were not being reported, causing a test case failure. If we move the
stuck waiter detection out of hangcheck and into the breadcrumb
mechanims (i.e. the waiter) itself, we can avoid this issue entirely.
This leaves hangcheck looking for a stuck GPU (inspecting for request
advancement and HEAD motion), and breadcrumbs looking for a stuck
waiter - hopefully make both easier to understand by their segregation.

v2: Reduce the error message as we now run independently of hangcheck,
and the hanging batch used by igt also counts as a stuck waiter causing
extra warnings in dmesg.
v3: Move the breadcrumb's hangcheck kickstart to the first missed wait.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97104
Fixes: 2529d570 (waiter"drm/i915: Drop racy markup of missed-irqs...")
Testcase: igt/drv_missed_irq
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470761272-1245-2-git-send-email-chris@chris-wilson.co.uk

One of the few guarantees we want the busy ioctl to provide is that the
reported busy writer is included in the set of busy read engines. This
should be provided by the ordering of setting and retiring the active
trackers, but we can do better by explicitly setting the busy read
engine flag for the last writer.

v2: More comments inside __busy_write_id() to explain why both fields
are set.

Fixes: 3fdc13c7 ("drm/i915: Remove (struct_mutex) locking for busy-ioctl")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470762505-12799-1-git-send-email-chris@chris-wilson.co.ukReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

I mistyped and added an extra _request_ to __i915_gem_active_get_rcu()
Also, the same happened to another comment for i915_gem_active_get_rcu()
Reported-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470758602-1338-1-git-send-email-chris@chris-wilson.co.uk

We don't have GPU reset support for gen2, which means the display
hardware is unaffected when a GPU hang is handled. However as the ring
has in fact stopped, any flips still in the ring will never complete,
and thus the display base address updates will never happen. So we
really need to fix that up manually just like we do on g4x+.

In fact, let's just use intel_has_gpu_reset() instead of IS_GEN2()
since that'll also handle cases where someone would disable the GPU
reset support on gen3/4 for whatever reason.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470428910-12125-5-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Factor out the "does the GPU reset clobber the display?" check into a
small helper.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470428910-12125-4-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Add force_reset_modeset_test as a parameter to force the modeset path during gpu reset.
This allows a IGT test to set the knob and trigger a hang to force the gpu reset,
even on platforms that wouldn't otherwise require it.

Changes since v1:
- Split out fix to separate commit.
Changes since v2:
- This commit is purely about force_reset_modeset_test now.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Testcase: drv_hangman.reset-with-forced-modeset
Tested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470428910-12125-3-git-send-email-ville.syrjala@linux.intel.comSigned-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

This function would call drm_modeset_lock_all, while the suspend/resume
functions already have their own locking. Fix this by factoring out
__intel_display_resume, and calling the atomic helpers for duplicating
atomic state and disabling all crtc's during suspend.

Changes since v1:
- Deal with -EDEADLK right after lock_all and clean up calls
  to hw readout.
- Always take all modeset locks so updates during gpu reset are blocked.
Changes since v2:
- Fix deadlock in intel_update_primary_planes.
- Move WARN_ON(EDEADLK) to __intel_display_resume.
- pctx -> ctx
- only call __intel_display_resume on success in intel_display_resume.
Changes since v3:
- Rebase on top of dev_priv -> dev change.
- Use drm_modeset_lock_all_ctx instead of drm_modeset_lock_all.
Changes since v4 [by vsyrjala]:
- Deal with skip_intermediate_wm
- Update comment w.r.t. mode_config.mutex vs. ->detect()
- Rebase due to INTEL_GEN() etc.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Fixes: e2c8b870 ("drm/i915: Use atomic helpers for suspend, v2.")
Cc: stable@vger.kernel.org
Tested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470428910-12125-2-git-send-email-ville.syrjala@linux.intel.com

Marking PCH transcoder FIFO underrun reporting as disabled for
transcoder B/C on LPT-H will block us from enabling the south error
interrupt. So let's only mark transcoder A underrun reporting as
disabled initially.

This is a little tricky to hit since you need a machine with LPT-H, and
the BIOS must enable either pipe B or C at boot. Then i915 would mark
the "transcoder B/C" underrun reporting as disabled and never enable it
again, meaning south interrupts would never get enabled either. The only
other interrupt in there is actually the poison interrupt which, if we
could ever trigger it, would just result in a little error in dmesg.

Here's the resulting change in SDEIMR on my HSW when I boot it with
multiple displays attached:
- (0x000c4004): 0xf115ffff
+ (0x000c4004): 0xf114ffff

My previous attempt [1] tried to fix this a little differently, but
Daniel requested I do this instead.

[1] https://lists.freedesktop.org/archives/intel-gfx/2015-November/081420.html

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470416417-15021-1-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

intel_enable_pipe() looks rather confusing when one side doesn't have
the curly braces, and the other one does. And what's even worse,
there's another if-else inside the braceless side. Let's put braces
around it to make it clear which branch goes where.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470418894-1249-1-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

When using RCU lookup for the request, commit 0eafec6d ("drm/i915:
Enable lockless lookup of request tracking via RCU"), we acknowledge that
we may race with another thread that could have reallocated the request.
In order for the first thread not to blow up, the second thread must not
clear the request completed before overwriting it. In the RCU lookup, we
allow for the engine/seqno to be replaced but we do not allow for it to
be zeroed.

The choice we make is to either add extra checking to the RCU lookup, or
embrace the inherent races (as intended). It is more complicated as we
need to manually clear everything we depend upon being zero initialised,
but we benefit from not emiting the memset() to clear the entire
frequently allocated structure (that memset turns up in throughput
profiles). And at the same time, the lookup remains flexible for future
adjustments.

v2: Old style LRC requires another variable to be initialize. (The
danger inherent in not zeroing everything.)
v3: request->batch also needs to be cleared
v4: signaling.tsk is no long used unset, but pid still exists

Fixes: 0eafec6d ("drm/i915: Enable lockless lookup of request...")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: "Goel, Akash" <akash.goel@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1470731014-6894-2-git-send-email-chris@chris-wilson.co.uk

In the debate as to whether the second read of active->request is
ordered after the dependent reads of the first read of active->request,
just give in and throw a smp_rmb() in there so that ordering of loads is
assured.

v2: Explain the manual smp_rmb()
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1470731014-6894-1-git-send-email-chris@chris-wilson.co.uk