One important part of this patch is we now write a scratch page
directory into any unused PDP descriptors. This matters for 2 reasons,
first, we're not allowed to just use 0, or an invalid pointer, and second,
we must wipe out any previous contents from the last context.

The latter point only matters with full PPGTT. The former point only
effect platforms with less than 4GB memory.

v2: Updated commit message to point that we must set unused PDPs to the
scratch page.

v3: Unmap scratch_pd in gen8_ppgtt_free.

v4: Initialize scratch_pd. (Mika)

Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: Michel Thierry <michel.thierry@intel.com> (v2+)
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Similar to gen6, we will use for_each_pde/for_each_pdpe
and pte/pde/pdpe_index to iterate over these new structures.

v2: Match trace_i915_va_teardown params
v3: Multiple rebases.
v4: Updated to use unmap_and_free_pt.
v5: teardown_va_range logic no longer needed.
v6: Rebase after s/page_tables/page_table/.
v7: Renamed commit to match what it does now (it was "Use dynamic
allocation idioms on free").
v8: Prevent (harmless) out of range access in gen8_for_each_pde and
gen8_for_each_pdpe_e.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: Michel Thierry <michel.thierry@intel.com> (v2+)
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
[danvet: s/BUG/WARN/]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Lets try to keep this consistent:

Page Directory Pointer (PDP).
Page Directory (PD), also known as page directory pointer entries.
Page Table (PT), also known as page directory entries.

s/struct i915_page_table_entry/struct i915_page_table/
s/struct i915_page_directory_entry/struct i915_page_directory/
s/struct i915_page_directory_pointer_entry/struct
i915_page_directory_pointer/
Suggested-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: NMichel Thierry <michel.thierry@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

To allow for views where the view type is not defined by the view type only,
like it is in stereo or rotated 90 degree view, change the semantic to require
the whole view structure for comparison when we match a GGTT view.

This allows including parameters like offset to be included in the view which
is useful for eg. partial views.

v3:
- Rely on ggtt_view type being 0 for non-GGTT vma's, which equals to
  I915_GGTT_VIEW_NORMAL. (Daniel Vetter)
- Do not use potentially slower comparison when we only want to know if
  something is or is not a normal view.
- Rebase on top of rotated view patches. Add rotated view singleton.
- If one view is missing in comparison they're equal only if both are missing.

v4:
- Use comparison helper in obj_to_ggtt_view too. (Tvrtko Ursulin)
- Do WARN_ON if one view is NULL. (Tvrtko Ursulin)

Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch continues on the idea from "Track GEN6 page table usage".
From here on, in the steady state, PDEs are all pointing to the scratch
page table (as recommended in the spec). When an object is allocated in
the VA range, the code will determine if we need to allocate a page for
the page table. Similarly when the object is destroyed, we will remove,
and free the page table pointing the PDE back to the scratch page.

Following patches will work to unify the code a bit as we bring in GEN8
support. GEN6 and GEN8 are different enough that I had a hard time to
get to this point with as much common code as I do.

The aliasing PPGTT must pre-allocate all of the page tables. There are a
few reasons for this. Two trivial ones: aliasing ppgtt goes through the
ggtt paths, so it's hard to maintain, we currently do not restore the
default context (assuming the previous force reload is indeed
necessary). Most importantly though, the only way (it seems from
empirical evidence) to invalidate the CS TLBs on non-render ring is to
either use ring sync (which requires actually stopping the rings in
order to synchronize when the sync completes vs. where you are in
execution), or to reload DCLV.  Since without full PPGTT we do not ever
reload the DCLV register, there is no good way to achieve this. The
simplest solution is just to not support dynamic page table
creation/destruction in the aliasing PPGTT.

We could always reload DCLV, but this seems like quite a bit of excess
overhead only to save at most 2MB-4k of memory for the aliasing PPGTT
page tables.

v2: Make the page table bitmap declared inside the function (Chris)
Simplify the way scratching address space works.
Move the alloc/teardown tracepoints up a level in the call stack so that
both all implementations get the trace.

v3: Updated trace event to spit out a name

v4: Aliasing ppgtt is now initialized differently (in setup global gtt)

v5: Rebase to latest code. Also removed unnecessary aliasing ppgtt check
for trace, as it is no longer possible after the PPGTT cleanup patch series
of a couple of months ago (Daniel).

v6: Implement changes from code review (Daniel):
 - allocate/teardown_va_range calls added.
 - Add a scratch page allocation helper (only need the address).
 - Move trace events to a new patch.
 - Use updated mark_tlbs_dirty.
 - Moved pt preallocation for aliasing ppgtt into gen6_ppgtt_init.

v7: teardown_va_range removed (Daniel).
    In init, gen6_ppgtt_clear_range call is only needed for aliasing ppgtt.

v8: Rebase after s/page_tables/page_table/.

v9: Remove unnecessary scratch flag in page_table struct, future patches
can just compare against ppgtt->scratch_pt, and alloc_pt_scratch becomes
redundant. Initialize scratch_pt and pt. (Mika)

v10: Clean up aliasing ppgtt init error path and prevent leaking the
ppgtt obj when init fails. (Mika)
Updated commit author. (Daniel)

Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: Michel Thierry <michel.thierry@intel.com> (v4+)
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Found by static analysis tool, this was harmless as the pt was not
used out of scope though.

Introduced by commit 678d96fb
("drm/i915: Track GEN6 page table usage").

Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NMichel Thierry <michel.thierry@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

90/270 rotated scanout needs a rotated GTT view of the framebuffer.

This is put in a separate VMA with a dedicated ggtt view and wired such that
it is created when a framebuffer is pinned to a 90/270 rotated plane.

Rotation is only possible with Yb/Yf buffers and error is propagated to
user space in case of a mismatch.

Special rotated page view is constructed at the VMA creation time by
borrowing the DMA addresses from obj->pages.

v2:
    * Do not bother with pages for rotated sg list, just populate the DMA
      addresses. (Daniel Vetter)
    * Checkpatch cleanup.

v3:
    * Rebased on top of new plane handling (create rotated mapping when
      setting the rotation property).
    * Unpin rotated VMA on unpinning from display plane.
    * Simplify rotation check using bitwise AND. (Chris Wilson)

v4:
    * Fix unpinning of optional rotated mapping so it is really considered
      to be optional.

v5:
   * Rebased for fb modifier changes.
   * Rebased for atomic commit.
   * Only pin needed view for display. (Ville Syrjälä, Daniel Vetter)

v6:
   * Rebased after preparatory work has been extracted out. (Daniel Vetter)

v7:
   * Slightly simplified tiling geometry calculation.
   * Moved rotated GGTT view implementation into i915_gem_gtt.c (Daniel Vetter)

v8:
   * Do not use i915_gem_obj_size to get object size since that actually
     returns the size of an VMA which may not exist.
   * Rebased for ggtt view changes.

v9:
   * Rebased after code review changes on the preceding patches.
   * Tidy function definitions. (Joonas Lahtinen)

For: VIZ-4726
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Michel Thierry <michel.thierry@intel.com> (v4)
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch was formerly known as, "Force pd restore when PDEs change,
gen6-7." I had to change the name because it is needed for GEN8 too.

The real issue this is trying to solve is when a new object is mapped
into the current address space. The GPU does not snoop the new mapping
so we must do the gen specific action to reload the page tables.

GEN8 and GEN7 do differ in the way they load page tables for the RCS.
GEN8 does so with the context restore, while GEN7 requires the proper
load commands in the command streamer. Non-render is similar for both.

Caveat for GEN7
The docs say you cannot change the PDEs of a currently running context.
We never map new PDEs of a running context, and expect them to be
present - so I think this is okay. (We can unmap, but this should also
be okay since we only unmap unreferenced objects that the GPU shouldn't
be tryingto va->pa xlate.) The MI_SET_CONTEXT command does have a flag
to signal that even if the context is the same, force a reload. It's
unclear exactly what this does, but I have a hunch it's the right thing
to do.

The logic assumes that we always emit a context switch after mapping new
PDEs, and before we submit a batch. This is the case today, and has been
the case since the inception of hardware contexts. A note in the comment
let's the user know.

It's not just for gen8. If the current context has mappings change, we
need a context reload to switch

v2: Rebased after ppgtt clean up patches. Split the warning for aliasing
and true ppgtt options. And do not break aliasing ppgtt, where to->ppgtt
is always null.

v3: Invalidate PPGTT TLBs inside alloc_va_range.

v4: Rename ppgtt_invalidate_tlbs to mark_tlbs_dirty and move
pd_dirty_rings from i915_address_space to i915_hw_ppgtt. Fixes when
neither ctx->ppgtt and aliasing_ppgtt exist.

v5: Removed references to teardown_va_range.

v6: Updated needs_pd_load_pre/post.

v7: Fix pd_dirty_rings check in needs_pd_load_post, and update/move
comment about updated PDEs to object_pin/bind (Mika).

Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: Michel Thierry <michel.thierry@intel.com> (v2+)
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Instead of implementing the full tracking + dynamic allocation, this
patch does a bit less than half of the work, by tracking and warning on
unexpected conditions. The tracking itself follows which PTEs within a
page table are currently being used for objects. The next patch will
modify this to actually allocate the page tables only when necessary.

With the current patch there isn't much in the way of making a gen
agnostic range allocation function. However, in the next patch we'll add
more specificity which makes having separate functions a bit easier to
manage.

One important change introduced here is that DMA mappings are
created/destroyed at the same page directories/tables are
allocated/deallocated.

Notice that aliasing PPGTT is not managed here. The patch which actually
begins dynamic allocation/teardown explains the reasoning for this.

v2: s/pdp.page_directory/pdp.page_directories
Make a scratch page allocation helper

v3: Rebase and expand commit message.

v4: Allocate required pagetables only when it is needed, _bind_to_vm
instead of bind_vma (Daniel).

v5: Rebased to remove the unnecessary noise in the diff, also:
 - PDE mask is GEN agnostic, renamed GEN6_PDE_MASK to I915_PDE_MASK.
 - Removed unnecessary checks in gen6_alloc_va_range.
 - Changed map/unmap_px_single macros to use dma functions directly and
   be part of a static inline function instead.
 - Moved drm_device plumbing through page tables operation to its own
   patch.
 - Moved allocate/teardown_va_range calls until they are fully
   implemented (in subsequent patch).
 - Merged pt and scratch_pt unmap_and_free path.
 - Moved scratch page allocator helper to the patch that will use it.

v6: Reduce complexity by not tearing down pagetables dynamically, the
same can be achieved while freeing empty vms. (Daniel)

v7: s/i915_dma_map_px_single/i915_dma_map_single
s/gen6_write_pdes/gen6_write_pde
Prevent a NULL case when only GGTT is available. (Mika)

v8: Rebased after s/page_tables/page_table/.

v9: Reworked i915_pte_index and i915_pte_count.
Also exercise bitmap allocation here (gen6_alloc_va_range) and fix
incorrect write_page_range in i915_gem_restore_gtt_mappings (Mika).

Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: Michel Thierry <michel.thierry@intel.com> (v3+)
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

No functional changes, but will improve code clarity and removed some
duplicated defines.
Signed-off-by: NMichel Thierry <michel.thierry@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

As we move toward dynamic page table allocation, it becomes much easier
to manage our data structures if break do things less coarsely by
breaking up all of our actions into individual tasks.  This makes the
code easier to write, read, and verify.

Aside from the dissection of the allocation functions, the patch
statically allocates the page table structures without a page directory.
This remains the same for all platforms,

The patch itself should not have much functional difference. The primary
noticeable difference is the fact that page tables are no longer
allocated, but rather statically declared as part of the page directory.
This has non-zero overhead, but things gain additional complexity as a
result.

This patch exists for a few reasons:
1. Splitting out the functions allows easily combining GEN6 and GEN8
code. Page tables have no difference based on GEN8. As we'll see in a
future patch when we add the DMA mappings to the allocations, it
requires only one small change to make work, and error handling should
just fall into place.

2. Unless we always want to allocate all page tables under a given PDE,
we'll have to eventually break this up into an array of pointers (or
pointer to pointer).

3. Having the discrete functions is easier to review, and understand.
All allocations and frees now take place in just a couple of locations.
Reviewing, and catching leaks should be easy.

4. Less important: the GFP flags are confined to one location, which
makes playing around with such things trivial.

v2: Updated commit message to explain why this patch exists

v3: For lrc, s/pdp.page_directory[i].daddr/pdp.page_directory[i]->daddr/

v4: Renamed free_pt/pd_single functions to unmap_and_free_pt/pd (Daniel)

v5: Added additional safety checks in gen8 clear/free/unmap.

v6: Use WARN_ON and return -EINVAL in alloc_pt_range (Mika).

v7: Make err_out loop symmetrical to the way we allocate in
alloc_pt_range. Also s/page_tables/page_table and correct commit
message (Mika)

Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: Michel Thierry <michel.thierry@intel.com> (v3+)
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Move the remaining members over to the new page table structures.

This can be squashed with the previous commit if desire. The reasoning
is the same as that patch. I simply felt it is easier to review if split.

v2: In lrc: s/ppgtt->pd_dma_addr[i]/ppgtt->pdp.page_directory[i].daddr/
v3: Rebase.
v4: Rebased after s/page_tables/page_table/.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: Michel Thierry <michel.thierry@intel.com> (v2+)
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

When we move to dynamic page allocation, keeping page_directory and pagetabs as
separate structures will help to break actions into simpler tasks.

To help transition the code nicely there is some wasted space in gen6/7.
This will be ameliorated shortly.

Following the x86 pagetable terminology:
PDPE = struct i915_page_directory_pointer_entry.
PDE = struct i915_page_directory_entry [page_directory].
PTE = struct i915_page_table_entry [page_tables].

v2: fixed mismatches after clean-up/rebase.

v3: Clarify the names of the multiple levels of page tables (Daniel)

v4: Addressing Mika's review comments.
s/gen8_free_page_directories/gen8_free_page_directory and free the
page tables for the directory there.
In gen8_ppgtt_allocate_page_directories, do not leak previously allocated
pt in case the page_directory alloc fails.
Update error return handling in gen8_ppgtt_alloc.

v5: Do not leak pt on error in gen6_ppgtt_allocate_page_tables. (Mika)

v6: s/page_tables/page_table/. (Mika)

Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: Michel Thierry <michel.thierry@intel.com> (v2+)
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NMichel Thierry <michel.thierry@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In gen8, 32b PPGTT has always had one "pdp" (it doesn't actually have
one, but it resembles having one). The #define was confusing as is, and
using "PDPE" is a much better description.

sed -i 's/GEN8_LEGACY_PDPS/GEN8_LEGACY_PDPES/' drivers/gpu/drm/i915/*.[ch]

It also matches the x86 pagetable terminology:
PTE  = Page Table Entry - pagetable level 1 page
PDE  = Page Directory Entry - pagetable level 2 page
PDPE = Page Directory Pointer Entry - pagetable level 3 page

And in the near future (for 48b addressing):
PML4E = Page Map Level 4 Entry

v2: Expanded information about Page Directory/Table nomenclature.

Cc: Daniel Vetter <daniel@ffwll.ch>
CC: Dave Gordon <david.s.gordon@intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: Michel Thierry <michel.thierry@intel.com> (v2)
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Things like reliable GGTT mappings and mirrored 2d-on-3d display will need
to map objects into the same address space multiple times.

Added a GGTT view concept and linked it with the VMA to distinguish between
multiple instances per address space.

New objects and GEM functions which do not take this new view as a parameter
assume the default of zero (I915_GGTT_VIEW_NORMAL) which preserves the
previous behaviour.

This now means that objects can have multiple VMA entries so the code which
assumed there will only be one also had to be modified.

Alternative GGTT views are supposed to borrow DMA addresses from obj->pages
which is DMA mapped on first VMA instantiation and unmapped on the last one
going away.

v2:
    * Removed per view special casing in i915_gem_ggtt_prepare /
      finish_object in favour of creating and destroying DMA mappings
      on first VMA instantiation and last VMA destruction. (Daniel Vetter)
    * Simplified i915_vma_unbind which does not need to count the GGTT views.
      (Daniel Vetter)
    * Also moved obj->map_and_fenceable reset under the same check.
    * Checkpatch cleanups.

v3:
    * Only retire objects once the last VMA is unbound.

v4:
    * Keep scatter-gather table for alternative views persistent for the
      lifetime of the VMA.
    * Propagate binding errors to callers and handle appropriately.

v5:
    * Explicitly look for normal GGTT view in i915_gem_obj_bound to align
      usage in i915_gem_object_ggtt_unpin. (Michel Thierry)
    * Change to single if statement in i915_gem_obj_to_ggtt. (Michel Thierry)
    * Removed stray semi-colon in i915_gem_object_set_cache_level.

For: VIZ-4544
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
[danvet: Drop hunk from i915_gem_shrink since it's just prettification
but upsets a __must_check warning.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The object structure contains the last read, write and fenced seqno values for
use in syncrhonisation operations. These have now been replaced with their
request structure counterparts.

Note that to ensure that objects do not end up with dangling pointers, the
assignments of last_*_req include reference count updates. Thus a request cannot
be freed if an object is still hanging on to it for any reason.

v2: Corrected 'last_rendering_' to 'last_read_' in a number of comments that did
not get updated when 'last_rendering_seqno' became 'last_read|write_seqno'
several millenia ago.

For: VIZ-4377
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NThomas Daniel <Thomas.Daniel@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now unused.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Found one more!

With this we can clear up the ggtt init code a bit, yay!
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

If these flags are on the object level it will be more difficult to allow
for multiple VMAs per object.

v2: Simplification and cleanup after code review comments (Chris Wilson).
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch is to address Daniels concerns over different code during reset:

http://lists.freedesktop.org/archives/intel-gfx/2014-June/047758.html

"The reason for aiming as hard as possible to use the exact same code for
driver load, gpu reset and runtime pm/system resume is that we've simply
seen too many bugs due to slight variations and unintended omissions."

Tested using igt drv_hangman.

V2: Cleaner way of preventing check_wedge returning -EAGAIN
V3: Clean the last_context during reset, to ensure do_switch() does the MI_SET_CONTEXT. As per review.
Signed-off-by: NMcAulay, Alistair <alistair.mcaulay@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
[danvet: Rebase over ctx->ppgtt rework and extend the comment in
check_wedge a bit.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We want to move the aliasing ppgtt cleanup back into the global
gtt cleanup code for symmetry, but first we need to create such
a place.
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Currently we abuse the aliasing ppgtt to set up the ppgtt support in
general. Which is a bit backwards since with full ppgtt we don't ever
need the aliasing ppgtt.

So untangle this and separate the ppgtt init from the aliasing
ppgtt. While at it drag it out of the context enabling (which just
does a switch to the default context).

Note that we still have the differentiation between synchronous and
asynchronous ppgtt setup, but that will soon vanish. So also correctly
wire up the return value handling to be prepared for when ->switch_mm
drops the synchronous parameter and could start to fail.
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We already needs this just as a safety check in case the preallocation
reservation dance fails. But we definitely need this to be able to
move tha aliasing ppgtt setup back out of the context code to this
place, where it belongs.
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Hardware contexts reference a ppgtt, not the other way round. And the
only user of this (in debugfs) actually only cares about which file
the ppgtt is associated with. So give it what it wants.

While at it give the ppgtt create function a proper name&place.
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

So when reviewing Michel's patch I've noticed a few things and cleaned
them up:
- The early checks in ppgtt_release are now redundant: The inactive
  list should always be empty now, so we can ditch these checks. Even
  for the aliasing ppgtt (though that's a different confusion) since
  we tear that down after all the objects are gone.
- The ppgtt handling functions are splattered all over. Consolidate
  them in i915_gem_gtt.c, give them OCD prefixes and add wrappers for
  get/put.
- There was a bit a confusion in ppgtt_release about whether it cares
  about the active or inactive list. It should care about them both,
  so augment the WARNINGs to check for both.

There's still create_vm_for_ctx left to do, put that is blocked on the
removal of ppgtt->ctx. Once that's done we can rename it to
i915_ppgtt_create and move it to its siblings for handling ppgtts.

v2: Move the ppgtt checks into the inline get/put functions as
suggested by Chris.

v3: Inline the now redundant ppgtt local variable.

Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

sanitize_enable_ppgtt is the function that checks all the conditions,
honoring a forced ppgtt status or doing auto-detect as necessary.  Just
make sure it returns the right value in all cases and use that in the
macros instead of the confusing intel_enable_ppgtt() function.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
[danvet: Don't reenable full ppgtt through the backdoor.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This adds support for a write-enable bit in the entry of GTT.
This is handled via a read-only flag in the GEM buffer object which
is then used to see how to set the bit when writing the GTT entries.
Currently by default the Batch buffer & Ring buffers are marked as read only.

v2: Moved the pte override code for read-only bit to 'byt_pte_encode'. (Chris)
    Fixed the issue of leaving 'gt_old_ro' as unused. (Chris)

v3: Removed the 'gt_old_ro' field, now setting RO bit only for Ring Buffers(Daniel).

v4: Added a new 'flags' parameter to all the pte(gen6) encode & insert_entries functions,
    in lieu of overloading the cache_level enum (Daniel).

v5: Removed the superfluous VLV check & changed the definition location of PTE_READ_ONLY flag (Imre)
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NAkash Goel <akash.goel@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Up until now, contexts had one (and only one) backing object that was
used by the hardware to save/restore render ring contexts (via the
MI_SET_CONTEXT command). Other rings did not have or need this, so
our i915_hw_context struct had a 1:1 relationship with a a real HW
context.

With Logical Ring Contexts and Execlists, this is not possible anymore:
all rings need a backing object, and it cannot be reused. To prepare
for that, rename our contexts to the more generic term intel_context.

No functional changes.
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In the upcoming patches we plan to break the correlation between
engine command streamers (a.k.a. rings) and ringbuffers, so it
makes sense to refactor the code and make the change obvious.

No functional changes.
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Ignore the cache bits in PPAT and just set the snoop bit where
appropriate. BDW WB is mapped to snooped access, while all other
modes are mapped to non-snooped access.

The hardware supposedly ignores everything except the snoop bit
in the PPAT entries.

Additionally the hardware actually enforces snooping for all
page table accesses, and thus the snoop bit is ignored for PDEs.

v2: Rebased on top of the bdw resume fix to reload the ppat entries.

v3: Rebase on top of the i915_gem_gtt.h header extraction.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> (v1)
Acked-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NRafael Barbalho <rafael.barbalho@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This file contains all necessary defines, prototypes and typesdefs for
manipulating GEN graphics address translation (this does not include the
legacy AGP driver)

Reiterating the comment in the header,
"Please try to maintain the following order within this file unless it
makes sense to do otherwise. From top to bottom:
1. typedefs
2. #defines, and macros
3. structure definitions
4. function prototypes

Within each section, please try to order by generation in ascending
order, from top to bottom (ie. GEN6 on the top, GEN8 on the bottom)."

I've made some minor cleanups, and fixed a couple of typos while here -
but there should be no functional changes.

The purpose of the patch is to reduce clutter in our main header file,
making room for new growth, and make documentation of our interfaces
easier by splitting things out.

With a little more work, like making i915_gtt a pointer, we could
potentially completely isolate this header from i915_drv.h. At the
moment however, I don't think it's worth the effort.

Personally, I would have liked to put the PTE encoding functions in this
file too, but I didn't want to rock the boat too much.

A similar patch has been in use on my machine for some time. This exact
patch though has only been compile tested.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>