Once the machine gets to a certain point in the suspend process, we
expect the GPU to be idle. If it is not, we might corrupt memory.
Empirically (with an early version of this patch) we have seen this is
not the case. We cannot currently explain why the latent GPU writes
occur.

In the technical sense, this patch is a workaround in that we have an
issue we can't explain, and the patch indirectly solves the issue.
However, it's really better than a workaround because we understand why
it works, and it really should be a safe thing to do in all cases.

The noticeable effect other than the debug messages would be an increase
in the suspend time. I have not measure how expensive it actually is.

I think it would be good to spend further time to root cause why we're
seeing these latent writes, but it shouldn't preclude preventing the
fallout.

NOTE: It should be safe (and makes some sense IMO) to also keep the
VALID bit unset on resume when we clear_range(). I've opted not to do
this as properly clearing those bits at some later point would be extra
work.

v2: Fix bugzilla link

Bugzilla: http://bugs.freedesktop.org/show_bug.cgi?id=65496
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=59321Tested-by: NTakashi Iwai <tiwai@suse.de>
Tested-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Tested-By: NTodd Previte <tprevite@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We need this to work around a corruption when the boot kernel image
loads the hibernated kernel image from swap on Haswell systems -
somehow not everything is properly shut off.

This is just the prep work, the next patch will implement the actual
workaround.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
[danvet: Add a commit message suitable for -fixes and add cc: stable]
Cc: stable@vger.kernel.org
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

No buffer overflows here, but better safe than sorry.

v2:
- Fixup the sizeof conversion, I've missed the pointer deref (Jani).
- Drop the redundant GFP_ZERO, kcalloc alreads memsets (Jani).
- Use kmalloc_array for the execbuf fastpath to avoid the memset
  (Chris). I've opted to leave all other conversions as-is since they
  aren't in a fastpath and dealing with cleared memory instead of
  random garbage is just generally nicer.

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
[danvet: Drop the contentious kmalloc_array hunk in execbuf.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Haswell GT3e has the unique feature of supporting Write-Through cacheing
of objects within the eLLC/LLC. The purpose of this is to enable the display
plane to remain coherent whilst objects lie resident in the eLLC/LLC - so
that we, in theory, get the best of both worlds, perfect display and fast
access.

However, we still need to be careful as the CPU does not see the WT when
accessing the cache. In particular, this means that we need to flush the
cache lines after writing to an object through the CPU, and on
transitioning from a cached state to WT.

v2: Actually do the clflush on transition to WT, nagging by Ville.
v3: Flush the CPU cache after writes into WT objects.
v4: Rease onto LLC updates and report WT as "uncached" for
get_cache_level_ioctl to remain symmetric with set_cache_level_ioctl.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

As mentioned in the previous commit, reads and writes from both the CPU
and GPU go through the LLC. This gives us coherency between the CPU and
GPU irrespective of the attribute settings either device sets. We can
use to avoid having to clflush even uncached memory.

Except for the scanout.

The scanout resides within another functional block that does not use
the LLC but reads directly from main memory. So in order to maintain
coherency with the scanout, writes to uncached memory must be flushed.
In order to optimize writes elsewhere, we start tracking whether an
framebuffer is attached to an object.

v2: Use pin_display tracking rather than fb_count (to ensure we flush
cursors as well etc) and only force the clflush along explicit writes to
the scanout paths (i.e. pin_to_display_plane and pwrite into scanout).

v3: Force the flush after hitting the slowpath in pwrite, as after
dropping the lock the object's cache domain may be invalidated. (Ville)

Based on a patch by Ville Syrjälä.
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>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

MLC_LLC was never validated for Sandybridge and was superseded by a new
level of cacheing for the GPU in Ivybridge. Update our names to be
consistent with usage, and in the process stop setting the unwanted bit
on Sandybridge.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
[danvet: s/BUG/WARN_ON(1) bikeshed.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Just some small cleanups, and a rename of vm->ggtt_vm requested by
Daniel.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Earlier in the conversion sequence we attempted to quickly wedge in the
transitional interface as static inlines.

Now that we're sure these interfaces are sane, for easier debug and to
decrease code size (since many of these functions may be called quite a
bit), make them real functions

While at it, kill off the set_color interface. We'll always have the
VMA, or easily get to it.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The default LLC age was changed:
commit 0d8ff15e
Author: Ben Widawsky <benjamin.widawsky@intel.com>
Date:   Thu Jul 4 11:02:03 2013 -0700

drm/i915/hsw: Set correct Haswell PTE encodings.

On the surface it would seem setting a default age wouldn't matter
because all GEM BOs are aged similarly, so the order in which objects
are evicted would not be subject to aging. The current working theory as
to why this caused a regression though is that LLC is a bit special in
that it is shared with the CPU. Presumably (not verified) the CPU
fetches cachelines with age 3, and therefore recently cached GPU objects
would be evicted before similar CPU object first when the LLC is full.
It stands to reason therefore that this would negatively impact CPU
bound benchmarks - but those seem to be low on the priority list.

eLLC OTOH does not have this same property as LLC. It should be used
entirely for the GPU, and so the age really shouldn't matter.
Furthermore, we have no evidence to suggest one is better than another
on eLLC. Since we've never properly supported eLLC before no, there
should be no regression. If the GPU client really wants "younger"
objects, they should use MOCS.

v2: Drop the extra #define (Chad)

v3: Actually git add

v4: Pimped commit message

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=67062Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NChad Versace <chad.versace@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The PTE layouts are the same for both ppgtt and gtt, so we can simplify
the setup for ppgtt by copying the encoding function pointer from gtt.
This prevents bugs where we update one function pointer, but forget the
other.

For instance,

commit 4d15c145
Author: Ben Widawsky <ben@bwidawsk.net>
Date:   Thu Jul 4 11:02:06 2013 -0700

    drm/i915: Use eLLC/LLC by default when available

only extends the gtt to use eLLC/LLC cacheing and forgets to also update
the ppgtt function pointer.

v2: Actually mention the bug being fixed (Kenneth)
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NKenneth Graunke <kenneth@whitecape.org>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Formerly: "drm/i915: Create VMAs (part 1)"

In a previous patch, the notion of a VM was introduced. A VMA describes
an area of part of the VM address space. A VMA is similar to the concept
in the linux mm. However, instead of representing regular memory, a VMA
is backed by a GEM BO. There may be many VMAs for a given object, one
for each VM the object is to be used in. This may occur through flink,
dma-buf, or a number of other transient states.

Currently the code depends on only 1 VMA per object, for the global GTT
(and aliasing PPGTT). The following patches will address this and make
the rest of the infrastructure more suited

v2: s/i915_obj/i915_gem_obj (Chris)

v3: Only move an object to the now global unbound list if there are no
more VMAs for the object which are bound into a VM (ie. the list is
empty).

v4: killed obj->gtt_space
some reworks due to rebase

v5: Free vma on error path (Imre)

v6: Another missed vma free in i915_gem_object_bind_to_gtt error path
(Imre)
Fixed vma freeing in stolen preallocation (Imre)
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NImre Deak <imre.deak@intel.com>
[danvet: Squash in fixup from Ben to not deref a non-existing vma in
set_cache_level, reported by Chris.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Every address space should support object allocation. It therefore makes
sense to have the allocator be part of the "superclass" which GGTT and
PPGTT will derive.

Since our maximum address space size is only 2GB we're not yet able to
avoid doing allocation/eviction; but we'd hope one day this becomes
almost irrelvant.

v2: Rebased
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The GTT and PPGTT can be thought of more generally as GPU address
spaces. Many of their actions (insert entries), state (LRU lists), and
many of their characteristics (size) can be shared. Do that.

The change itself doesn't actually impact most of the VMA/VM rework
coming up, it just fits in with the grand scheme of abstracting the GPU
VM operations. GGTT will usually be a special case where we either know
an object must be in the GGTT (dislay engine, workarounds, etc.).

The scratch page is left as part of the VM (even though it's currently
shared with the ppgtt code) because in the future when we have Full
PPGTT, I intend to create a separate scratch page for each.

v2: Drop usage of i915_gtt_vm (Daniel)
Make cleanup also part of the parent class (Ben)
Modified commit msg
Rebased

v3: Properly share scratch page (Imre)
Finish commit message (Daniel, Imre)
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

DRI clients really should be using MOCS to get fine grained streaming
cache controls. With that note, I *hope* that this patch doesn't improve
performance overwhelmingly, because if it does - it means there is a
problem elsewhere.

In any case, the kernel, and old userspace should get some benefit from
this, so let's do it. eLLC is always a good default, and really not
using it is the special case for MOCS.

References: http://www.intel.com/newsroom/kits/restricted/ha$well!/pdfs/4th_Gen_Intel_Core_PressBriefing_5-29.pdf (page 57)
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The cacheability controls have changed, and the bits have been
rearranged in general.

Note that age 0 is the oldest (most likely to get evicted) and age 3
is the youngest (most likely to stick around for a bit). We've picked
0 for no reason, but atm it shouldn't matter anyway (since we don't
yet try to differentiate between different objects).

v2: Remove comments for snb/ivb cache leves, that's a separate change.

v3: Resolve conflicts due to patch series reordering.

v4: Rebased on top of Kenneth Graunke's ->pte_encode refactoring.

v5: Removed eLLC bits for separate patch.

In the internal repository this was:
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NKenneth Graunke <kenneth@whitecape.org>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
[danvet: Add comment about cache ages as requested by Ben provoked due
to a question from Damien.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Embedding the node in the obj is more natural in the transition to VMAs
which will also have embedded nodes. This change also helps transition
away from put_block to remove node.

Though it's quite an uncommon occurrence, it's somewhat convenient to not
fail at bind time because we cannot allocate the node. Though in
practice there are other allocations (like the request structure) which
would probably make this point not terribly useful.

Quoting Daniel:
Note that the only difference between put_block and remove_node is
that the former fills up the preallocation cache. Which we don't need
anyway and hence is just wasted space.

v2: Clean up the stolen preallocation code.
Rebased on the reserve_node patches
renames ggtt_ stuff to gtt_ stuff
WARN_ON if the object is already bound (which doesn't mean it's in the
bound list, tricky)
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

With the getters in place from the previous patch this members serves no
purpose other than saving one spare pointer chase, which will be killed
in the next patch anyway.

Moving to VMAs, this members adds unnecessary confusion since an object
may exist at different offsets in different VMs.

v2: Properly preserve the stolen offset. This code is a bit hacky but it
all goes away when we embed the drm_mm_node and removes the need for the
incorrect patch I submitted previously: "Use gtt_space->start for stolen
reservation"
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Soon we want to gut a lot of our existing assumptions how many address
spaces an object can live in, and in doing so, embed the drm_mm_node in
the object (and later the VMA).

It's possible in the future we'll want to add more getter/setter
methods, but for now this is enough to enable the VMAs.

v2: Reworked commit message (Ben)
Added comments to the main functions (Ben)
sed -i "s/i915_gem_obj_set_color/i915_gem_obj_ggtt_set_color/" drivers/gpu/drm/i915/*.[ch]
sed -i "s/i915_gem_obj_bound/i915_gem_obj_ggtt_bound/" drivers/gpu/drm/i915/*.[ch]
sed -i "s/i915_gem_obj_size/i915_gem_obj_ggtt_size/" drivers/gpu/drm/i915/*.[ch]
sed -i "s/i915_gem_obj_offset/i915_gem_obj_ggtt_offset/" drivers/gpu/drm/i915/*.[ch]
(Daniel)

v3: Rebased on new reserve_node patch
Changed DRM_DEBUG_KMS to actually work (will need fixing later)
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

With the previous patch we no longer actually create a node, we simply
find the correct hole and occupy it. This very well could have been
squashed with the last patch, but since I already had David's review, I
figured it's easiest to keep it distinct.

Also update the users in i915. Conveniently this is the only user of the
interface.

CC: David Airlie <airlied@linux.ie>
CC: <dri-devel@lists.freedesktop.org>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Acked-by: NDavid Airlie <airlied@linux.ie>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For an upcoming patch where we introduce the i915 VMA, it's ideal to
have the drm_mm_node as part of the VMA struct (ie. it's pre-allocated).
Part of the conversion to VMAs is to kill off obj->gtt_space. Doing this
will break a bunch of code, but amongst them are 2 callers of
drm_mm_create_block(), both related to stolen memory.

It also allows us to embed the drm_mm_node into the object currently
which provides a nice transition over to the new code.

v2: Reordered to do before ripping out obj->gtt_offset.
Some minor cleanups made available because of reordering.

v3: s/continue/break on failed stolen node allocation (David)
Set obj->gtt_space on failed node allocation (David)
Only unref stolen (fix double free) on failed create_stolen (David)
Free node, and NULL it in failed create_stolen (David)
Add back accidentally removed newline (David)

CC: <dri-devel@lists.freedesktop.org>
Reviewed-by: NDavid Herrmann <dh.herrmann@gmail.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Acked-by: NDavid Airlie <airlied@linux.ie>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Just for compactness.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The original pte_encode function needed the dev argument so we could do
platform specific handling via IS_GENX, etc. With the merging of a pte
encoding function there should never been a need to quirk away gen
specific details.

The patch doesn't do much but makes the upcoming reworks in gtt/ppgtt/mm
slightly (albeit, ever so) easier.
Reviewed-by: NKenneth Graunke <kenneth@whitecape.org>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There isn't any special reason to do this other than it makes it obvious
that the two members are connected.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

A previous patch had set up the ppgtt and ggtt to use the same scratch
page, but still kept around both pointers. Kill it, it's not needed and
gets in our way for upcoming cleanups.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Nothing outside of i915_gem_gtt.c and more specifically, the relevant
gen specific init function should need to know about number of PDEs, or
PTEs per PD. Exposing this will only lead to circumventing using the
upcoming VM abstraction.

To accomplish this, move the defines into the .c file, rename the PDE
define to be GEN6, and make the PTE count less of a magic number.

The remaining code in the global gtt setup is a bit messy, but an
upcoming patch will clean that one up.

v2: Don't hardcode number of PDEs (Daniel + Jesse)
Reworded commit message to reflect change.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Since it will be used for the global bound/unbound list with full PPGTT,
this helps clarify things for upcoming code rework.
Recommended-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This reverts commit 03752f5b.

This revert requires a bit of explanation on how I understand things
work. Internally the architects/designers decide how the stolen encoding
works. We put it in a doc. BIOS writers take these docs and implement
it. Driver writers read the doc too, and read the value left by the BIOS
writers, and then we make magic.

The failing here is that in the docs we had[1] contained two different
definitions for this register for Gen7. (We have both a PCI register,
and an MMIO, and each of these were different). At the time [2] of
03752f5b, we asked the architects what the correct value should be; but
that doesn't match the reality (BIOS) unfortunately.

So on all machines I can get my hands on, this revert is the right thing
to do. I've also worked with the product group to confirm that they
agree this revert is what we should do. People using HW made my "people"
who both write their own BIOS, and have access to our docs (Apple?).
Investigations are still ongoing about whether we need to add a list
of machines needing special handling, but this patch should be the
right thing for pretty much everyone.

[1] The docs are still wrong on this one. Now instead of two registers with
two definitions, we have one register with BOTH definitions, progress?
[2] The open source PRMs have the "wrong" definitions in chapter Volume
1 part6, section 1.1.12.

This digging was inspired by Paulo.

Cc: Paulo Zanoni <przanoni@gmail.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
[danvet: Augment the patch saying that it's still a bit unclear
whether there are any machines out there with "wrong" firmware and
whether we need to add a list to handle them specially.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It also makes some sense IMO to have these two functions separate
irrespective of the number of callers.

Only the single caller for now, but that will change as we add more
PPGTTs.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
[danvet: Resolve conflict.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Because PPGTT PDEs within the GTT are calculated in cachelines
(HW guys consistency ftw) we do a divide which will wreak havoc if this
is wrong, and I know that from experience).

If/when we move to multiple PPGTTs this will have to become a WARN, and
return an error. For now however it should always be considered fatal,
and only a developer could hit it.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
[danvet: s/BUG/WARN]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

When ppgtt is enabled, dev_priv->gtt.total has excluded the gtt space
occupied by ppgtt table in i915_gem_init_global_gtt() function. So the
calculation of first_pd_entry_in_global_pt doesn't need to subtract
I915_PPGTT_PD_ENTRIES again. Or else PPGTT directory table will be
destroyed by global gtt allocation.

This regression has been introduced in

commit a54c0c27
Author: Ben Widawsky <ben@bwidawsk.net>
Date:   Thu Jan 24 14:45:00 2013 -0800

    drm/i915: remove intel_gtt structure

The breakage is pretty subtile since the old gtt_total_entries
included the pde range, whereas the new on did not.

Cc: stable@vger.kernel.org
Signed-off-by: Xiong Zhang<xiong.y.zhang@intel.com>
[danvet: Add regression citation and cc: stable. Thanks to Chris for
correcting my wrong guess about which commit broke things.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that we have function pointers, it's cleaner to just create a new
per-platform PTE encoding function.

This should be identical in behavior to the previous code.

v2: Drop accidental inline keyword on hsw_pte_encode.
Signed-off-by: NKenneth Graunke <kenneth@whitecape.org>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Tested-by: Daniel Leung <daniel.leung@linux.intel.com> [v1]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

On Bay Trail, bit 1 means "writeable by the GPU."  Failing to set that
means basically anything using the GPU will cause hangs.

v2: Drop accidental inline keyword on byt_pte_encode.
Signed-off-by: NKenneth Graunke <kenneth@whitecape.org>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Tested-by: Daniel Leung <daniel.leung@linux.intel.com> [v1]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Sandybridge/Ivybridge, Bay Trail, and Haswell all have slightly
different page table entry formats.  Rather than polluting one function
with generation checks, simply use a function pointer and set up the
correct PTE encoding function at startup.

v2: Move the gen6_gtt_pte_t typedef to i915_drv.h so that the function
    pointers and implementations have identical signatures.  Also remove
    inline keyword on gen6_pte_encode.  Both suggested by Jani Nikula.
Signed-off-by: NKenneth Graunke <kenneth@whitecape.org>
Reviewed-by: NJani Nikula <jani.nikula@linux.intel.com>
Tested-by: Daniel Leung <daniel.leung@linux.intel.com> [v1]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Looks like a some remnant from a rebase.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

IVB and HSW use different encodings for the PPGTT cacheability bits in
the GAM_ECOCHK register.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

According to BSpec GAC_ECO_BITS register exists on Gen7 platforms as
well. Configure it accordingly.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

GAC_ECO_BITS has a bit similar to GAM_ECOCHK's ECOCHK_SNB_BIT. Add
the define, and enable it on SNB.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

I'm really not happy that we have to support this, but this will be the
simplest way to handle cases where PPGTT init can fail, which I promise
will be coming in the future.

v2: Resolve conflicts due to patch series reordering.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net> (v1)
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This will allow us to carry on if we've cleaned up the PPGTT. The usage
for this is coming up - it simplifies handling a failed PPGTT init.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
[danvet: Spill the secrets about failing ppgtt init.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Since we've already set up a nice vtable to abstract other PPGTT
functions, also abstract the actual register programming to enable
things.

This function will probably need to change a bit as we implement real
processes.

v2: Resolve conflicts due to patch series reordering.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net> (v1)
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>