This patch sets up all of the tracking and copying necessary to
use batch pools with the command parser and dispatches the copied
(shadow) batch to the hardware.

After this patch, the parser is in 'enabling' mode.

Note that performance takes a hit from the copy in some cases
and will likely need some work. At a rough pass, the memcpy
appears to be the bottleneck. Without having done a deeper
analysis, two ideas that come to mind are:
1) Copy sections of the batch at a time, as they are reached
   by parsing. Might improve cache locality.
2) Copy only up to the userspace-supplied batch length and
   memset the rest of the buffer. Reduces the number of reads.

v2:
- Remove setting the capacity of the pool
- One global pool instead of per-ring pools
- Replace batch_obj with shadow_batch_obj and hook into eb->vmas
- Memset any space in the shadow batch beyond what gets copied
- Rebased on execlist prep refactoring

v3:
- Rebase on chained batch handling
- Squash in setting the secure dispatch flag
- Add a note about the interaction w/secure dispatch pinning
- Check for request->batch_obj == NULL in i915_gem_free_request

v4:
- Fix read domains for shadow_batch_obj
- Remove the set_to_gtt_domain call from i915_parse_cmds
- ggtt_pin/unpin in the parser block to simplify error handling
- Check USES_FULL_PPGTT before setting DISPATCH_SECURE flag
- Remove i915_gem_batch_pool_put calls

v5:
- Move 'pending_read_domains |= I915_GEM_DOMAIN_COMMAND' after
  the parser (danvet, from v4 0/7 feedback)

Issue: VIZ-4719
Signed-off-by: NBrad Volkin <bradley.d.volkin@intel.com>
Reviewed-By: NJon Bloomfield <jon.bloomfield@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>

All the code above is now using requests not seqnos so it is possible to convert
the trace functions across. Note that rather than get into problematic reference
counting issues, the trace code only saves the seqno and ring values from the
request structure not the structure pointer itself.

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>

There is no longer any need to retrieve a seqno value from an i915_add_request()
call. The calling code already knows which request structure is being processed
(it can only be ring->OLR). And as the request itself is now used in preference
to the basic seqno value, the latter is now redundant in this situation.

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>

The OLS value is now obsolete. Exactly the same value is guarateed to be always
available as PLR->seqno. Thus it is safe to remove the OLS completely. And also
to rename the PLR to OLR to keep the 'outstanding lazy ...' naming convention
valid.

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>

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>

It happens on occasion that developers of generic user-space applications
abuse the dumb buffer API to get hold of drm buffers that they can both
mmap() and use for GPU acceleration, using the assumptions that dumb buffers
and buffers available for GPU are
a) The same type and can be aribtrarily type-casted.
b) fully coherent.

This patch makes the most widely used drivers warn nicely when that happens,
the next step will be to fail.

v2: Move drmP.h changes to drm_gem.h. Fix Radeon dumb mmap breakage.
Signed-off-by: NThomas Hellstrom <thellstrom@vmware.com>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Again just complicates gem init functions and makes a general mess out
of everything.

Good riddance!

v2: In my enthusiasm to start removing dri1/ums crud I went overboard a
bit and killed parts of hangcheck. Resurrect it.
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

With the deprecation of UMS, and by association DRI1, we have a tough
choice when updating the ring access routines. We either rewrite the
DRI1 routines blindly without testing (so likely to be broken) or take
the liberty of declaring them no longer supported and remove them
entirely. This takes the latter approach.

v2: Also remove the DRI1 sarea updates
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Fix rebase conflicts.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Always require PIN_GLOBAL when we want a mappable offset (PIN_MAPPABLE).
This causes the pin to fixup the global binding in cases were the vma
was already bound (and due to the proceeding bug, we considered it to be
already mappable).

References: https://bugs.freedesktop.org/show_bug.cgi?id=85671Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Add WARN_ON to check that PIN_MAP implies PIN_GLOBAL as
discussed on irc.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

libva uses chained batch buffers in a way that the command parser
can't generally handle. Fortunately, libva doesn't need to write
registers from batch buffers in the way that mesa does, so this
patch causes the driver to fall back to non-secure dispatch if
the parser detects a chained batch buffer.

Note: The 2nd hunk to munge the error code of the parser looks a bit
superflous. At least until we have the batch copy code ready and can
run the cmd parser in granting mode. But it isn't since we still need
to let existing libva buffers pass (though not with elevated privs
ofc!).

Testcase: igt/gem_exec_parse/chained-batch
Signed-off-by: NBrad Volkin <bradley.d.volkin@intel.com>
[danvet: Add note - this confused me in review and Brad clarified
things (after a few mails ...).]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

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>

There's a bit a confusion since we track the global gtt,
the aliasing and real ppgtt in the ctx->vm pointer. And not
all callers really bother to check for the different cases and just
presume that it points to a real ppgtt.

Now looking closely we don't actually need ->vm to always point at an
address space - the only place that cares actually has fixup code
already to decide whether to look at the per-proces or the global
address space.

So switch to just tracking the ppgtt directly and ditch all the
extraneous code.

v2: Fixup the ppgtt debugfs file to not oops on a NULL ctx->ppgtt.
Also drop the early exit - without aliasing ppgtt we want to dump all
the ppgtts of the contexts if we have full ppgtt.

v3: Actually git add the compile fix.
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Cc: "Thierry, Michel" <michel.thierry@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
OTC-Jira: VIZ-3724
[danvet: Resolve conflicts with execlist patches while applying.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is what i915_gem_do_execbuffer calls when it wants to execute some
worload in an Execlists world.

v2: Check arguments before doing stuff in intel_execlists_submission. Also,
get rel_constants parsing right.
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
[danvet: Drop the chipset flush, that's pre-gen6. And appease
checkpatch a bit .... again!]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

As suggested by Daniel Vetter. The idea, in subsequent patches, is to
provide an alternative to these vfuncs for the Execlists submission
mechanism.

v2: Splitted into two and reordered to illustrate our intentions, instead
of showing it off. Also, remove the add_request vfunc and added the
stop_ring one.
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
[danvet:
- Make checkpatch happy.
- Be grumpy about the excessive vtable.
- Ditch gt->is_ring_initialized.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The backing objects and ringbuffers for contexts created via open
fd are actually empty until the user starts sending execbuffers to
them. At that point, we allocate & populate them. We do this because,
at create time, we really don't know which engine is going to be used
with the context later on (and we don't want to waste memory on
objects that we might never use).

v2: As contexts created via ioctl can only be used with the render
ring, we have enough information to allocate & populate them right
away.

v3: Defer the creation always, even with ioctl-created contexts, as
requested by Daniel Vetter.
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Even though we should not try to use 4+GiB GTTs on 32-bit systems, by
using a local variable we can future proof the code whilst making it
easier to read.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Appease checkpatch a bit.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Part of the pre-validation for an execbuffer call is that there is at
least one object in the execlist. As we bail if we fail to lookup any
object, we can be sure that after the eb_lookup_vma() there is at least
one object in the vma list and so we do not need to assert.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ben Widawsky <benjamin.widawsky@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We have an implementation requirement that precludes the user from
requesting a ggtt entry when the device is operating in ppgtt mode. Move
the current check from inside the execbuffer object collation to the
prevalidation phase.

v2: Roll both invalid flags checks into one
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Based upon a hunk from a patch from Chris Wilson, but augmented to:
- Process the batch in the full ppgtt vm so that self-relocations
  match again with userspace's expectations..
- Add a comment why plain pin for the global gtt binding is safe at
  that point.

v2: Drop local bind_vm variable (Chris).

v3: Explain why this works despite the lack of proper active tracking
for the ggtt batch vma.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ben Widawsky <benjamin.widawsky@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This migrates the fence tracking onto the existing seqno
infrastructure so that the later conversion to tracking via requests is
simplified.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Move the decision on whether we need to have a mappable object during
execbuffer to the fore and then reuse that decision by propagating the
flag through to reservation. As a corollary, before doing the actual
relocation through the GTT, we can make sure that we do have a GTT
mapping through which to operate.

Note that the key to make this work is to ditch the
obj->map_and_fenceable unbind optimization - with full ppgtt it
doesn't make a lot of sense any more anyway.

v2: Revamp and resend to ease future patches.
v3: Refresh patch rationale

References: https://bugs.freedesktop.org/show_bug.cgi?id=81094Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ben Widawsky <benjamin.widawsky@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
[danvet: Explain why obj->map_and_fenceable is key and split out the
secure batch fix.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This reverts commit 48ba8137.

Thanks to Chris:
"drm_file->is_master is not synomous with having drm_file->master ==
drm_file->minor->master. This is because drm_file->master is the same
for all drm_files of the same generation and so when there is a master,
every drm_file believes itself to be the master. Confusion ensues and
things go pear shaped when one file is closed and there is no master
anymore."

Conflicts:
	drivers/gpu/drm/drm_drv.c
	drivers/gpu/drm/drm_stub.c

The drm_file->is_master field is redundant as it's equivalent to:
    drm_file->master && drm_file->master == drm_file->minor->master

1) "=>"
  Whenever we set drm_file->is_master, we also set:
      drm_file->minor->master = drm_file->master;

  Whenever we clear drm_file->is_master, we also call:
      drm_master_put(&drm_file->minor->master);
  which implicitly clears it to NULL.

2) "<="
  minor->master cannot be set if it is non-NULL. Therefore, it stays as
  is unless a file drops it.

  If minor->master is NULL, it is only set by places that also adjust
  drm_file->is_master.

Therefore, we can safely drop is_master and replace it by an inline helper
that matches:
    drm_file->master && drm_file->master == drm_file->minor->master
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>

So that we isolate the legacy ringbuffer submission mechanism, which becomes
a good candidate to be abstracted away. This is prep-work for Execlists (which
will its own workload submission mechanism).

No functional changes.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is an Execlists preparatory patch, since they make context ID become an
overloaded term:

- In the software, it was used to distinguish which context userspace was
  trying to use.
- In the BSpec, the term is used to describe the 20-bits long field the
  hardware uses to it to discriminate the contexts that are submitted to
  the ELSP and inform the driver about their current status (via Context
  Switch Interrupts and Context Status Buffers).

Initially, I tried to make the different meanings converge, but it proved
impossible:

- The software ctx->id is per-filp, while the hardware one needs to be
  globally unique.
- Also, we multiplex several backing states objects per intel_context,
  and all of them need unique HW IDs.
- I tried adding a per-filp ID and then composing the HW context ID as:
  ctx->id + file_priv->id + ring->id, but the fact that the hardware only
  uses 20-bits means we have to artificially limit the number of filps or
  contexts the userspace can create.

The ctx->user_handle renaming bits are done with this Cocci patch (plus
manual frobbing of the struct declaration):

    @@
    struct intel_context c;
    @@
    - (c).id
    + c.user_handle

    @@
    struct intel_context *c;
    @@
    - (c)->id
    + c->user_handle

Also, while we are at it, s/DEFAULT_CONTEXT_ID/DEFAULT_CONTEXT_HANDLE and
change the type to unsigned 32 bits.

v2: s/handle/user_handle and change the type to uint32_t as suggested by
Chris Wilson.

Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org> (v1)
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

So these are the guts of the new beast. This tracks when a frontbuffer
gets invalidated (due to frontbuffer rendering) and hence should be
constantly scaned out, and when it's flushed again and can be
compressed/one-shot-upload.

Rules for flushing are simple: The frontbuffer needs one more full
upload starting from the next vblank. Which means that the flushing
can _only_ be called once the frontbuffer update has been latched.

But this poses a problem for pageflips: We can't just delay the
flushing until the pageflip is latched, since that would pose the risk
that we override frontbuffer rendering that has been scheduled
in-between the pageflip ioctl and the actual latching.

To handle this track asynchronous invalidations (and also pageflip)
state per-ring and delay any in-between flushing until the rendering
has completed. And also cancel any delayed flushing if we get a new
invalidation request (whether delayed or not).

Also call intel_mark_fb_busy in both cases in all cases to make sure
that we keep the screen at the highest refresh rate both on flips,
synchronous plane updates and for frontbuffer rendering.

v2: Lots of improvements

Suggestions from Chris:
- Move invalidate/flush in flush_*_domain and set_to_*_domain.
- Drop the flush in busy_ioctl since it's redundant. Was a leftover
  from an earlier concept to track flips/delayed flushes.
- Don't forget about the initial modeset enable/final disable.
  Suggested by Chris.

Track flips accurately, too. Since flips complete independently of
rendering we need to track pending flips in a separate mask. Again if
an invalidate happens we need to cancel the evenutal flush to avoid
races.

v3:
Provide correct header declarations for flip functions. Currently not
needed outside of intel_display.c, but part of the proper interface.

v4: Add proper domain management to fbcon so that the fbcon buffer is
also tracked correctly.

v5: Fixup locking around the fbcon set_to_gtt_domain call.

v6: More comments from Chris:
- Split out fbcon changes.
- Drop superflous checks for potential scanout before calling intel_fb
  functions - we can micro-optimize this later.
- s/intel_fb_/intel_fb_obj_/ to make it clear that this deals in gem
  object. We already have precedence for fb_obj in the pin_and_fence
  functions.

v7: Clarify the semantics of the flip flush handling by renaming
things a bit:
- Don't go through a gem object but take the relevant frontbuffer bits
  directly. These functions center on the plane, the actual object is
  irrelevant - even a flip to the same object as already active should
  cause a flush.
- Add a new intel_frontbuffer_flip for synchronous plane updates. It
  currently just calls intel_frontbuffer_flush since the implemenation
  differs.

This way we achieve a clear split between one-shot update events on
one side and frontbuffer rendering with potentially a very long delay
between the invalidate and flush.

Chris and I also had some discussions about mark_busy and whether it
is appropriate to call from flush. But mark busy is a state which
should be derived from the 3 events (invalidate, flush, flip) we now
have by the users, like psr does by tracking relevant information in
psr.busy_frontbuffer_bits. DRRS (the only real use of mark_busy for
frontbuffer) needs to have similar logic. With that the overall
mark_busy in the core could be removed.

v8: Only when retiring gpu buffers only flush frontbuffer bits we
actually invalidated in a batch. Just for safety since before any
additional usage/invalidate we should always retire current rendering.
Suggested by Chris Wilson.

v9: Actually use intel_frontbuffer_flip in all appropriate places.
Spotted by Chris.

v10: Address more comments from Chris:
- Don't call _flip in set_base when the crtc is inactive, avoids redunancy
  in the modeset case with the initial enabling of all planes.
- Add comments explaining that the initial/final plane enable/disable
  still has work left to do before it's fully generic.

v11: Only invalidate for gtt/cpu access when writing. Spotted by Chris.

v12: s/_flush/_flip/ in intel_overlay.c per Chris' comment.

Cc: Rodrigo Vivi <rodrigo.vivi@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>

CHECK   linux/drivers/gpu/drm/i915/i915_gem_execbuffer.c
linux/drivers/gpu/drm/i915/i915_gem_execbuffer.c:1529:47: warning: incorrect type in initializer (different address spaces)
linux/drivers/gpu/drm/i915/i915_gem_execbuffer.c:1529:47:    expected struct drm_i915_gem_exec_object2 *user_exec_list
linux/drivers/gpu/drm/i915/i915_gem_execbuffer.c:1529:47:    got void [noderef] <asn:1>*
linux/drivers/gpu/drm/i915/i915_gem_execbuffer.c:1533:61: warning: incorrect type in argument 1 (different address spaces)
linux/drivers/gpu/drm/i915/i915_gem_execbuffer.c:1533:61:    expected void [noderef] <asn:1>*dst
linux/drivers/gpu/drm/i915/i915_gem_execbuffer.c:1533:61:    got unsigned long long *<noident>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is pure evil. Userspace, I'm looking at you SNA, repacks batch
buffers on the fly after generation as they are being passed to the
kernel for execution. These batches also contain self-referenced
relocations as a single buffer encompasses the state commands, kernels,
vertices and sampler. During generation the buffers are placed at known
offsets within the full batch, and then the relocation deltas (as passed
to the kernel) are tweaked as the batch is repacked into a smaller buffer.
This means that userspace is passing negative relocations deltas, which
subsequently wrap to large values if the batch is at a low address. The
GPU hangs when it then tries to use the large value as a base for its
address offsets, rather than wrapping back to the real value (as one
would hope). As the GPU uses positive offsets from the base, we can
treat the relocation address as the minimum address read by the GPU.
For the upper bound, we trust that userspace will not read beyond the
end of the buffer.

So, how do we fix negative relocations from wrapping? We can either
check that every relocation looks valid when we write it, and then
position each object such that we prevent the offset wraparound, or we
just special-case the self-referential behaviour of SNA and force all
batches to be above 256k. Daniel prefers the latter approach.

This fixes a GPU hang when it tries to use an address (relocation +
offset) greater than the GTT size. The issue would occur quite easily
with full-ppgtt as each fd gets its own VM space, so low offsets would
often be handed out. However, with the rearrangement of the low GTT due
to capturing the BIOS framebuffer, it is already affecting kernels 3.15
onwards. I think only IVB+ is susceptible to this bug, but the workaround
should only kick in rarely, so it seems sensible to always apply it.

v3: Use a bias for batch buffers to prevent small negative delta relocations
from wrapping.

v4 from Daniel:
- s/BIAS/BATCH_OFFSET_BIAS/
- Extract eb_vma_misplaced/i915_vma_misplaced since the conditions
  were growing rather cumbersome.
- Add a comment to eb_get_batch explaining why we do this.
- Apply the batch offset bias everywhere but mention that we've only
  observed it on gen7 gpus.
- Drop PIN_OFFSET_FIX for now, that slipped in from a feature patch.

v5: Add static to eb_get_batch, spotted by 0-day tester.

Testcase: igt/gem_bad_reloc
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78533
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> (v3)
Cc: stable@vger.kernel.org
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We only want to modifiy a single field in the userspace view of the
execbuffer command buffer, so explicitly change that rather than copy
everything back again.

This serves two purposes:

1. The single fields are much cheaper to copy (constant size so the
copy uses special case code) and much smaller than the whole array.

2. We modify the array for internal use that need to be masked from
the user.

Note: We need this backported since without it the next bugfix will
blow up when userspace recycles batchbuffers and relocations.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
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>

Adding stuff at the bottom is really no how this should be done, since
that's the place for ums/dri dungeons.

This was added in

commit a8ebba75
Author: Zhao Yakui <yakui.zhao@intel.com>
Date:   Thu Apr 17 10:37:40 2014 +0800

    drm/i915: Use the coarse ping-pong mechanism based on drm fd to dispatch the BSD command on BDW GT3

Also add a note to prevent this from happening again - people really
should be less lazy and take more time to look for a good home of
their new driver-global state.

Cc: Imre Deak <imre.deak@intel.com>
Cc: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

More fallout from

commit c8725f3d
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Mon Mar 17 12:21:55 2014 +0000

    drm/i915: Do not call retire_requests from wait_for_rendering

is that we can completely fill all of memory using small objects, such
that we exhaust the filp space, and spend all of our time evicting
objects from the aperture. As such, we never fill the ring, and never
trigger the last resort flushing in

commit 1cf0ba14
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Mon May 5 09:07:33 2014 +0100

    drm/i915: Flush request queue when waiting for ring space

and so all the requests are left active and the objects keep that last
active reference. Eventually the system comes to a halt as it runs out
of memory.

The impact is mainly limited to test cases as regular userspace will
trigger retirement by manually checking whether an object is active.

Testcase: igt/gem_lut_handle
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78724Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Tested-by: NGuo Jinxian <jinxianx.guo@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Somehow UXA submits a completely bogus DR4 value since essentially
forever. It was originally introduced in

commit bade7d7d2505a10a8a7d24b084aff9742e2d6d64
Author: Eric Anholt <eric@anholt.net>
Date:   Fri Jun 6 14:03:25 2008 -0700

    Use the DRM for submitting batchbuffers when available.

and dutifully copied around ever since. Since we want to keep the
general dirt catching around just special case the UXA value.

This regression was introduced in

commit 9cb34664
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu Apr 24 08:09:11 2014 +0200

    drm/i915: Catch dirt in unused execbuffer fields

Comment from Chris' review:

"To be fair, it is a sensible value if one supposes a Region style API to
cliprects. Under that API, DR[14] define the extents of the clip region,
and ((0,0), (0,0)) [DR1==DR4==0] would mean all clipped, do not draw
anything."

v2: Pimp commit message a bit and remove the double space.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78494
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jörg Otte <jrg.otte@gmail.com>
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

All the rest of the code to enable this is in my branch. Without my
branch, hitting > 32b offsets is impossible. The code has always
"supported" 64b, but it's never actually been run of tested. This change
doesn't actually fix anything. [1] I am not sure why X won't work yet. I
do not get hangs or obvious errors.

There are 3 fixes grouped together here. First is to remove the
hardcoded 0 for the upper dword of the relocation. The next fix is to
use a 64b value for target_offset. The final fix is to not directly
apply target_offset to reloc->delta. reloc->delta is part of ABI, and so
we cannot change it. As it stands, 32b is enough to represent everything
we're interested in representing anyway. The main problem is, we cannot
add greater than 32b values to it directly.

[1] Almost all of intel-gpu-tools is not yet ready to test 64b
relocations. There are a few places that expect 32b values for offsets
and these all won't work.

Cc: Rafael Barbalho <rafael.barbalho@intel.com>
Cc: Chris 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>

Previously, our code only had a 32b offset value for where the
batchbuffer starts. With full PPGTT, and 64b canonical GPU address
space, that is an insufficient value. The code to expand is pretty
straight forward, and only one platform needs to do anything with the
extra bits.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NRafael Barbalho <rafael.barbalho@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

A common issue we have is that retiring requests causes recursion
through GTT manipulation or page table manipulation which we can only
handle at very specific points. However, to maintain internal
consistency (enforced through our sanity checks on write_domain at
various points in the GEM object lifecycle) we do need to retire the
object prior to marking it with a new write_domain, and also clear the
write_domain for the implicit flush following a batch.

Note that this then allows the unbound objects to still be on the active
lists, and so care must be taken when removing objects from unbound lists
(similar to the caveats we face processing the bound lists).

v2: Fix i915_gem_shrink_all() to handle updated object lifetime rules,
by refactoring it to call into __i915_gem_shrink().

v3: Missed an object-retire prior to changing cache domains in
i915_gem_object_set_cache_leve()

v4: Rebase
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Tested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NBrad Volkin <bradley.d.volkin@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The BDW GT3 has two independent BSD rings, which can be used to process the
video commands. To be simpler, it is transparent to user-space driver/middle.
Instead the kernel driver will decide which ring is to dispatch the BSD video
command.

As every BSD ring is powerful, it is enough to dispatch the BSD video command
based on the drm fd. In such case it can play back video stream while encoding
another video stream. The coarse ping-pong mechanism is used to determine
which BSD ring is used to dispatch the BSD video command.

V1->V2: Follow Daniel's comment and use the simple ping-pong mechanism.
This is only to add the support of dual BSD rings on BDW GT3 machine.
The further optimization will be considered in another patch set.

V2->V3: Follow Daniel's comment to use the struct_mutext instead of
atomic_t during determining which ring can be used to dispatch Video command.
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NZhao Yakui <yakui.zhao@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NZhao Yakui <yakui.zhao@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>