Since the scratch allocation and cleanup is shared by all engine
submission backends, move it out of the legacy intel_ringbuffer.c and
into the new home for common routines, intel_engine_cs.c
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471254551-25805-20-git-send-email-chris@chris-wilson.co.uk

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/1471254551-25805-19-git-send-email-chris@chris-wilson.co.uk

Use the GGTT VMA as the primary cookie for handing ring objects as
the most common action upon the ring is mapping and unmapping which act
upon the VMA itself. By restructuring the code to work with the ring
VMA, we can shrink the code and remove a few cycles from context pinning.

v2: Move the flush of the object back to before the first pin. We use
the am-I-bound? query to only have to check the flush on the first
bind and so avoid stalling on active rings.
Lots of little renames and small hoops.
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/1471254551-25805-18-git-send-email-chris@chris-wilson.co.uk

Access through the GTT requires the device to be awake. Ideally
i915_vma_pin_iomap() is short-lived and the pinning demarcates the
access through the iomap. This is not entirely true, we have a mixture
of long lived pins that exceed the wakelock (such as legacy ringbuffers)
and short lived pin that do live within the wakelock (such as execlist
ringbuffers).
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/1471254551-25805-17-git-send-email-chris@chris-wilson.co.uk

We know that the only access to the context object is via the GPU, and
the only time when it can be out of the GPU domain is when it is swapped
out and unbound. Therefore we only need to clflush the object when
binding, thus avoiding any potential stall on touching the domain on an
active context.
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/1471254551-25805-16-git-send-email-chris@chris-wilson.co.uk

When working with contexts, we most frequently want the GGTT VMA for the
context state, first and foremost. Since the object is available via the
VMA, we need only then store the VMA.

v2: Formatting tweaks to debugfs output, restored some comments removed
in the next patch
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/1471254551-25805-15-git-send-email-chris@chris-wilson.co.uk

v2: Rename functions to suit their more active role
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/1471254551-25805-14-git-send-email-chris@chris-wilson.co.uk

Lookup the GGTT vma once for the object assigned to the fence, and then
derive everything from that vma.
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/1471254551-25805-13-git-send-email-chris@chris-wilson.co.uk

Since the guc allocates and pins and object into the GGTT for its usage,
it is more natural to use that pinned VMA as our resource cookie.

v2: Embrace naming tautology
v3: Rewrite comments for guc_allocate_vma()
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/1471254551-25805-12-git-send-email-chris@chris-wilson.co.uk

The VMA are unreferenced, they belong to the object and live until they
are closed. However, if we want to use the VMA as a cookie and use it to
keep the object alive, we want to hold onto a reference to the object
for the lifetime of the VMA cookie. To facilitate this, add a couple of
simple wrappers for managing the reference count on the object owning the
VMA.
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/1471254551-25805-11-git-send-email-chris@chris-wilson.co.uk

A simple little macro to clear a pointer and return the old value. This
is useful for writing

	value = *ptr;
	if (!value)
		return;

	*ptr = 0;
	...
	free(value);

in a slightly more concise form:

	value = fetch_and_zero(ptr);
	if (!value)
		return;

	...
	free(value);

with the idea that this establishes a pattern that may be extended for
atomic use (using xchg or cmpxchg) i.e. atomic_fetch_and_zero() and
similar to llist.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471254551-25805-10-git-send-email-chris@chris-wilson.co.uk

In many places, we wish to store the VMA in preference to the object
itself and so being able to create the persistent VMA is useful.
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/1471254551-25805-9-git-send-email-chris@chris-wilson.co.uk

Previously, we would only set the vma->pages pointer for GGTT entries.
However, if we always set it, we can use it to prettify some code that
may want to access the backing store associated with the VMA (as
assigned to the VMA).
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/1471254551-25805-8-git-send-email-chris@chris-wilson.co.uk

It's an outright programming error, so explode if it is ever hit.
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/1471254551-25805-7-git-send-email-chris@chris-wilson.co.uk

No longer is knowing how much of the GTT (both mappable aperture and
beyond) relevant, and the output clutters the real information - that is
how many objects are allocated and bound (and by who) so that we can
quickly grasp if there is a leak.

v2: Relent, and rename pinned to indicate display only. Since the
display objects are semi-static and are of variable size, they are the
interesting objects to watch over time for aperture leaking. The other
pins are either static (such as the scratch page) or very short lived
(such as execbuf) and not part of the precious GGTT.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1471254551-25805-6-git-send-email-chris@chris-wilson.co.uk

Only those objects pinned to the display have semi-permanent pins of a
global nature (other pins are transient within their local vm). Simplify
i915_gem_pinned to only show the pertinent information about the pinned
objects within the GGTT.

v2: i915_gem_gtt_info is still shared with debugfs/i915_gem_gtt,
rename i915_gem_pinned to i915_gem_pin_display to better reflect its
contents
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/1471254551-25805-5-git-send-email-chris@chris-wilson.co.uk

These two files (i915_gem_active, i915_gem_inactive) no longer give
pertinent information since active/inactive tracking is per-vm and so we
need the information per-vm. They are obsolete so remove them.
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/1471254551-25805-4-git-send-email-chris@chris-wilson.co.uk

With execlists, we have context objects everywhere, not just RCS. So
store them for post-mortem debugging. This also has a secondary effect
of removing one more unsafe list iteration with using preserved state
from the hanging request. And now we can cross-reference the request's
context state with that loaded by the GPU.
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/1471254551-25805-3-git-send-email-chris@chris-wilson.co.uk

When capturing the error state, we do not need to know about every
address space - just those that are related to the error. We know which
context is active at the time, therefore we know which VM are implicated
in the error. We can then restrict the VM which we report to the
relevant subset.

v2: s/i/count_active/ (and similar)
    Rewrite label generation for "Buffers"
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/1471254551-25805-2-git-send-email-chris@chris-wilson.co.uk

Not only does it make for good documentation and debugging aide, but it is
also vital for when we want to unwind requests - such as when throwing away
an incomplete request.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1470414607-32453-2-git-send-email-arun.siluvery@linux.intel.comReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471254551-25805-1-git-send-email-chris@chris-wilson.co.uk

For convenience when debugging user issues show the autotuning
RPS parameters in debugfs/i915_rps_boost_info.

v2: Refine the presentation
v3: Style
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: fritsch@kodi.tv
Link: http://patchwork.freedesktop.org/patch/msgid/1471181336-27523-1-git-send-email-chris@chris-wilson.co.ukReviewed-by: NDavid Weinehall <david.weinehall@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471250973-31277-1-git-send-email-chris@chris-wilson.co.uk

Closed vma are removed from the obj->vma_list so that they cannot be
found by userspace. However, this means that when forcibly unbinding an
object, we have to wait upon all rendering to that object first in order
for the closed, but active, vma to be reaped and their bindings removed.
Reported-by: NMatthew Auld <matthew.auld@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97343
Fixes: aa653a68 ("drm/i915: Be more careful when unbinding vma")
Fixes: 8a3b3d57 (" drm/i915: Convert non-blocking userptr waits...")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471196681-30043-2-git-send-email-chris@chris-wilson.co.ukReviewed-by: NMatthew Auld <matthew.auld@intel.com>
Tested-by: NMatthew Auld <matthew.auld@intel.com>

If the obj->vma_list is empty, we immediately return ret. However, we
are doing so having never set it to any value, it should be zero!
Reported-by: NMatthew Auld <matthew.auld@intel.com>
References: https://bugs.freedesktop.org/show_bug.cgi?id=97343
Fixes: aa653a68 ("drm/i915: Be more careful when unbinding vma")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471196681-30043-1-git-send-email-chris@chris-wilson.co.ukReviewed-by: NMatthew Auld <matthew.auld@intel.com>

This patch provides the infrastructure for performing a 16-byte aligned
read from WC memory using non-temporal instructions introduced with sse4.1.
Using movntdqa we can bypass the CPU caches and read directly from memory
and ignoring the page attributes set on the CPU PTE i.e. negating the
impact of an otherwise UC access. Copying using movntdqa from WC is almost
as fast as reading from WB memory, modulo the possibility of both hitting
the CPU cache or leaving the data in the CPU cache for the next consumer.
(The CPU cache itself my be flushed for the region of the movntdqa and on
later access the movntdqa reads from a separate internal buffer for the
cacheline.) The write back to the memory is however cached.

This will be used in later patches to accelerate accessing WC memory.

v2: Report whether the accelerated copy is successful/possible.
v3: Function alignment override was only necessary when using the
function target("sse4.1") - which is not necessary for emitting movntdqa
from __asm__.
v4: Improve notes on CPU cache behaviour vs non-temporal stores.
v5: Fix byte offsets for unrolled moves.
v6: Find all remaining typos of "movntqda", use kernel_fpu_begin.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Akash Goel <akash.goel@intel.com>
Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471001999-17787-2-git-send-email-chris@chris-wilson.co.uk

vmaps has a provision for controlling the page protection bits, with which
we can use to control the mapping type, e.g. WB, WC, UC or even WT.
To allow the caller to choose their mapping type, we add a parameter to
i915_gem_object_pin_map - but we still only allow one vmap to be cached
per object. If the object is currently not pinned, then we recreate the
previous vmap with the new access type, but if it was pinned we report an
error. This effectively limits the access via i915_gem_object_pin_map to a
single mapping type for the lifetime of the object. Not usually a problem,
but something to be aware of when setting up the object's vmap.

We will want to vary the access type to enable WC mappings of ringbuffer
and context objects on !llc platforms, as well as other objects where we
need coherent access to the GPU's pages without going through the GTT

v2: Remove the redundant braces around pin count check and fix the marker
     in documentation (Chris)

v3:
- Add a new enum for the vmalloc mapping type & pass that as an argument to
   i915_object_pin_map. (Tvrtko)
- Use PAGE_MASK to extract or filter the mapping type info and remove a
   superfluous BUG_ON.(Tvrtko)

v4:
- Rename the enums and clean up the pin_map function. (Chris)

v5: Drop the VM_NO_GUARD, minor cosmetics.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NAkash Goel <akash.goel@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471001999-17787-1-git-send-email-chris@chris-wilson.co.uk

This reverts
commit 2ab9f587
Author: Peter Chen <peter.chen@nxp.com>
Date:   Fri Jul 15 11:17:03 2016 +0800
    gpu: drm: omapdrm: dss-of: add missing of_node_put after calling of_parse_phandle

The of_get_next_parent will drop refcount on the passed node, so the reverted
patch is wrong, thanks for Tomi Valkeinen points it.

Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: NPeter Chen <peter.chen@nxp.com>
Acked-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: NSean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1470908694-16362-1-git-send-email-peter.chen@nxp.com

For reasons that entirely elude me fb.h exposes all the structures,
even when it is not enabled. Except for special stuff like fb_defio.

Which means all the drivers which haven't yet switched over to the
defio support in the helpers and still roll their own, will fail
to compile when fbdev emulation is disabled. Protect just those
bits, as a gnarly reminder that conversion to the core defio helpers
would be good.

Cc: Dave Airlie <airlied@redhat.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1470847958-28465-6-git-send-email-daniel.vetter@ffwll.ch

Seems to at least compile fine, only change needed was to use
the fb_set_suspend helper.

Cc: alexander.deucher@amd.com
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1470847958-28465-5-git-send-email-daniel.vetter@ffwll.ch

vmwgfx doesn't actually build without that.

It would be great if vmwgfx could switch over to the fbdev emulation
helpers, since those will take care of all this already. I guess one
reason to not do that was lack of defio support in the helpers, but
that's fixed now. If there's any other hold-up, we should figure out
what it is and whether it makes sense to address it.

Cc: Sinclair Yeh <syeh@vmware.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470847958-28465-4-git-send-email-daniel.vetter@ffwll.ch

Everyone who uses the fbdev emulation helpers doesn't need to include
fb.h directly. Remove it.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1470847958-28465-3-git-send-email-daniel.vetter@ffwll.ch

Lots of drivers don't properly compile without this when CONFIG_FB=n.
It's kinda a hack, but since CONFIG_FB doesn't stub any fucntions when
it's disabled I think it makes sense to add it to drm_fb_helper.h.

Long term we probably need to rethink all the logic to unload firmware
framebuffer drivers, at least if we want to be able to move away from
CONFIG_FB and fbcon.

v2: Unfortunately just stubbing out remove_conflicting_framebuffers in
drm_fb_helper.h upset gcc about static vs. non-static declarations, so
a new wrapper it needs to be. Means more churn :(

Cc: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Cc: Noralf Trønnes <noralf@tronnes.org>
Cc: tomi.valkeinen@ti.com
Cc: dh.herrmann@gmail.com
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470847958-28465-2-git-send-email-daniel.vetter@ffwll.ch

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