After mi_set_context() succeeds, we need to update the state of the
engine's last_context. This ensures that we hold a pin on the context
whilst the hardware may write to it. However, since we didn't complete
the post-switch setup of the context, we need to force the subsequent
use of the same context to complete the setup (which means updating
should_skip_switch()).
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460565315-7748-15-git-send-email-chris@chris-wilson.co.uk

Having the !RCS legacy context switch threaded through the RCS switching
code makes it much harder to follow and understand. In the next patch, I
want to fix a bug handling the incomplete switch, this is made much
simpler if we segregate the two paths now.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1460565315-7748-14-git-send-email-chris@chris-wilson.co.uk

Two concurrent writes into the same register cacheline has the chance of
killing the machine on Ivybridge and other gen7. This includes LRI
emitted from the command parser.  The MI_SET_CONTEXT itself serves as
serialising barrier and prevents the pair of register writes in the first
packet from triggering the fault.  However, if a second switch-context
immediately occurs then we may have two adjacent blocks of LRI to the
same registers which may then trigger the hang. To counteract this we
need to insert a delay after the second register write using SRM.

This is easiest to reproduce with something like
igt/gem_ctx_switch/interruptible that triggers back-to-back context
switches (with no operations in between them in the command stream,
which requires the execbuf operation to be interrupted after the
MI_SET_CONTEXT) but can be observed sporadically elsewhere when running
interruptible igt. No reports from the wild though, so it must be of low
enough frequency that no one has correlated the random machine freezes
with i915.ko

The issue was introduced with
commit 2c550183 [v3.19]
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Tue Dec 16 10:02:27 2014 +0000

    drm/i915: Disable PSMI sleep messages on all rings around context switches

Testcase: igt/gem_ctx_switch/render-interruptible #ivb
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: NDaniel Vetter <daniel@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1460565315-7748-11-git-send-email-chris@chris-wilson.co.uk

We can use the new pin/lazy unpin API for simplicity
and more performance in the execlist submission paths.

v2:
  * Fix error handling and convert more users.
  * Compact some names for readability.

v3:
  * intel_lr_context_free was not unpinning.
  * Special case for GPU reset which otherwise unbalances
    the HWS object pages pin count by running the engine
    initialization only (not destructors).

v4:
  * Rebased on top of hws setup/init split.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1460472042-1998-1-git-send-email-tvrtko.ursulin@linux.intel.com
[tursulin: renames: s/hwd/hws/, s/obj_addr/vaddr/]
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Having provided for_each_engine_id() for cases where the third (id)
argument is useful, we can now replace all the remaining instances with
a simpler version that takes only two parameters. In many cases, this
also allows the elimination of the local variable used in the iterator
(usually 'i').

v2:
    s/dev_priv/(dev_priv__)/ in body of for_each_engine_masked() [Chris Wilson]
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458757194-17783-2-git-send-email-david.s.gordon@intel.com

Refer to Global GTT consistently as GGTT, thus rename dev_priv->gtt
to dev_priv->ggtt and struct i915_gtt to struct i915_ggtt.

Fix a couple of whitespace problems while at it.

v2:
- Fix a typo in commit message.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

Where we have a request we can use req->i915 directly instead
of going through the engine and device. Coccinelle script:

@@
function f;
identifier r;
@@
f(..., struct drm_i915_gem_request *r, ...)
{
...
- engine->dev->dev_private
+ r->i915
...
}
@@
struct drm_i915_gem_request *req;
@@
(
  req->
- engine->dev->dev_private
+ i915
)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1458219850-21007-1-git-send-email-tvrtko.ursulin@linux.intel.com

In full gpu reset we prime all engines and reset domains corresponding to
each engine. Per engine reset is just a special case of this process
wherein only a single engine is reset. This change is aimed to modify
relevant functions to achieve this. There are some other steps we carry out
in case of engine reset which are addressed in later patches.

Reset func now accepts a mask of all engines that need to be reset. Where
per engine resets are supported, error handler populates the mask
accordingly otherwise all engines are specified.

v2: ALL_ENGINES mask fixup, better for_each_ring_masked (Chris)
v3: Whitespace fixes (Chris)
v4: Rebase due to s/ring/engine

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458143640-20563-1-git-send-email-mika.kuoppala@intel.com

Some trivial ones, first pass done with Coccinelle:

@@
@@
(
- I915_NUM_RINGS
+ I915_NUM_ENGINES
|
- intel_ring_flag
+ intel_engine_flag
|
- for_each_ring
+ for_each_engine
|
- i915_gem_request_get_ring
+ i915_gem_request_get_engine
|
- intel_ring_idle
+ intel_engine_idle
|
- i915_gem_reset_ring_status
+ i915_gem_reset_engine_status
|
- i915_gem_reset_ring_cleanup
+ i915_gem_reset_engine_cleanup
|
- init_ring_lists
+ init_engine_lists
)

But that didn't fully work so I cleaned it up with:

for f in *.[hc]; do sed -i -e s/I915_NUM_RINGS/I915_NUM_ENGINES/ $f; done
for f in *.[hc]; do sed -i -e s/i915_gem_request_get_ring/i915_gem_request_get_engine/ $f; done
for f in *.[hc]; do sed -i -e s/intel_ring_flag/intel_engine_flag/ $f; done
for f in *.[hc]; do sed -i -e s/intel_ring_idle/intel_engine_idle/ $f; done
for f in *.[hc]; do sed -i -e s/init_ring_lists/init_engine_lists/ $f; done
for f in *.[hc]; do sed -i -e s/i915_gem_reset_ring_cleanup/i915_gem_reset_engine_cleanup/ $f; done
for f in *.[hc]; do sed -i -e s/i915_gem_reset_ring_status/i915_gem_reset_engine_status/ $f; done

v2: Rebase.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

below and a couple manual fixups.

@@
identifier I, J;
@@
struct I {
...
- struct intel_engine_cs *J;
+ struct intel_engine_cs *engine;
...
}
@@
identifier I, J;
@@
struct I {
...
- struct intel_engine_cs J;
+ struct intel_engine_cs engine;
...
}
@@
struct drm_i915_private *d;
@@
(
- d->ring
+ d->engine
)
@@
struct i915_execbuffer_params *p;
@@
(
- p->ring
+ p->engine
)
@@
struct intel_ringbuffer *r;
@@
(
- r->ring
+ r->engine
)
@@
struct drm_i915_gem_request *req;
@@
(
- req->ring
+ req->engine
)

v2: Script missed the tracepoint code - fixed up by hand.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

@@
identifier func;
@@
func(..., struct intel_engine_cs *
- ring
+ engine
, ...)
{
<...
- ring
+ engine
...>
}
@@
identifier func;
type T;
@@
T func(..., struct intel_engine_cs *
- ring
+ engine
, ...);
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Done by the Coccinelle script below plus a manual
intervention to GEN8_RING_SEMAPHORE_INIT.

@@
expression E;
@@
- struct intel_engine_cs *ring = E;
+ struct intel_engine_cs *engine = E;
<+...
- ring
+ engine
...+>
@@
@@
- struct intel_engine_cs *ring;
+ struct intel_engine_cs *engine;
<+...
- ring
+ engine
...+>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Elsewhere we have adopted the convention of using '_link' to denote
elements in the list (and '_list' for the actual list_head itself), and
that the name should indicate which list the link belongs to (and
preferrably not just where the link is being stored).

s/vma_link/obj_link/ (we iterate over obj->vma_list)
s/mm_list/vm_link/ (we iterate over vm->[in]active_list)
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

Unknown parameters, especially structure padding, are expected to invoke
rejection with -EINVAL.

v2: similar issue exists for context-create

Testcase: igt/gem_ctx_create/invalid-pad
Testcase: igt/gem_ctx_bad_destroy/invalid-pad
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89602
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93999Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1454690759-31201-1-git-send-email-chris@chris-wilson.co.uk

In GuC mode LRC pinning lifetime depends exclusively on the
request liftime. Since that is terminated by the seqno update
that opens up a race condition between GPU finishing writing
out the context image and the driver unpinning the LRC.

To extend the LRC lifetime we will employ a similar approach
to what legacy ringbuffer submission does.

We will start tracking the last submitted context per engine
and keep it pinned until it is replaced by another one.

Note that the driver unload path is a bit fragile and could
benefit greatly from efforts to unify the legacy and exec
list submission code paths.

At the moment i915_gem_context_fini has special casing for the
two which are potentialy not needed, and also depends on
i915_gem_cleanup_ringbuffer running before itself.

v2:
 * Move pinning into engine->emit_request and actually fix
   the reference/unreference logic. (Chris Wilson)

 * ring->dev can be NULL on driver unload so use a different
   route towards it.

v3:
 * Rebase.
 * Handle the reset path. (Chris Wilson)
 * Exclude default context from the pinning - it is impossible
   to get it right before default context special casing in
   general is eliminated.

v4:
 * Rebased & moved context tracking to
   intel_logical_ring_advance_and_submit.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Issue: VIZ-4277
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Nick Hoath <nicholas.hoath@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453976997-25424-1-git-send-email-tvrtko.ursulin@linux.intel.com

Will enable cleaner implementation of a following fix and
easier code unification in the future.

Idea and code by Chris Wilson.

v2: Do not return before last_contexts on engines are unpinned.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Chris Wilson <chris@chris-wilson.co.uk>

Now that we've eliminated a lot of uses of ring->default_context,
we can eliminate the pointer itself.

All the engines share the same default intel_context, so we can just
keep a single reference to it in the dev_priv structure rather than one
in each of the engine[] elements. This make refcounting more sensible
too, as we now have a refcount of one for the one pointer, rather than
a refcount of one but multiple pointers.

From an idea by Chris Wilson.

v2:	transform an extra instance of ring->default_context introduced by
    42f1cae8 drm/i915: Restore inhibiting the load of the default context
    That patch's commentary includes:
	v2: Mark the global default context as uninitialized on GPU reset so
	    that the context-local workarounds are reloaded upon re-enabling
    The code implementing that now also benefits from the replacement of
    the multiple (per-ring) pointers to the default context with a single
    pointer to the unique kernel context.

v4:	Rebased, remove underused local (Nick Hoath)
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NNick Hoath <nicholas.hoath@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1453230175-19330-3-git-send-email-david.s.gordon@intel.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Following a GPU reset, we may leave the context in a poorly defined
state, and reloading from that context will leave the GPU flummoxed. For
secondary contexts, this will lead to that context being banned - but
currently it is also causing the default context to become banned,
leading to turmoil in the shared state.

This is a regression from

commit 6702cf16 [v4.1]
Author: Ben Widawsky <benjamin.widawsky@intel.com>
Date:   Mon Mar 16 16:00:58 2015 +0000

    drm/i915: Initialize all contexts

which quietly introduced the removal of the MI_RESTORE_INHIBIT on the
default context.

v2: Mark the global default context as uninitialized on GPU reset so
that the context-local workarounds are reloaded upon re-enabling.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1448630935-27377-1-git-send-email-chris@chris-wilson.co.ukReviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Cc: stable@vger.kernel.org
[danvet: This seems to fix a gpu hand on after the first resume,
resulting in any future suspend operation failing with -EIO because
the gpu seems to be in a funky state. Somehow this patch fixes that.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
(cherry picked from commit 42f1cae8)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Following a GPU reset, we may leave the context in a poorly defined
state, and reloading from that context will leave the GPU flummoxed. For
secondary contexts, this will lead to that context being banned - but
currently it is also causing the default context to become banned,
leading to turmoil in the shared state.

This is a regression from

commit 6702cf16 [v4.1]
Author: Ben Widawsky <benjamin.widawsky@intel.com>
Date:   Mon Mar 16 16:00:58 2015 +0000

    drm/i915: Initialize all contexts

which quietly introduced the removal of the MI_RESTORE_INHIBIT on the
default context.

v2: Mark the global default context as uninitialized on GPU reset so
that the context-local workarounds are reloaded upon re-enabling.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1448630935-27377-1-git-send-email-chris@chris-wilson.co.ukReviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Cc: stable@vger.kernel.org
[danvet: This seems to fix a gpu hand on after the first resume,
resulting in any future suspend operation failing with -EIO because
the gpu seems to be in a funky state. Somehow this patch fixes that.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Do some further clean up based on the initial review of
drm/i915: Separate cherryview from valleyview.

In this case, in i915_gem_alloc_context_obj() only call
i915_gem_object_set_cache_level() for Ivy Bridge devices
since later platforms don't have L3 control bits in the PTE.

v2: Expand comment to mention snooping requirement. (Ville, Imre)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NWayne Boyer <wayne.boyer@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449596332-23470-1-git-send-email-wayne.boyer@intel.comReviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

The cherryview device shares many characteristics with the valleyview
device.  When support was added to the driver for cherryview, the
corresponding device info structure included .is_valleyview = 1.
This is not correct and leads to some confusion.

This patch changes .is_valleyview to .is_cherryview in the cherryview
device info structure and simplifies the IS_CHERRYVIEW macro.
Then where appropriate, instances of IS_VALLEYVIEW are replaced with
IS_VALLEYVIEW || IS_CHERRYVIEW or equivalent.

v2: Use IS_VALLEYVIEW || IS_CHERRYVIEW instead of defining a new macro.
    Also add followup patches to fix issues discovered during the first
    review. (Ville)
v3: Fix some style issues and one gen check. Remove CRT related changes
    as CRT is not supported on CHV. (Imre, Ville)
v4: Make a few more optimizations. (Ville)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NWayne Boyer <wayne.boyer@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449692975-14803-1-git-send-email-wayne.boyer@intel.comReviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: NJani Nikula <jani.nikula@intel.com>

Commit e9f24d5f
Author: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Date:   Mon Oct 5 13:26:36 2015 +0100

    drm/i915: Clean up associated VMAs on context destruction

Added a warning based on an incorrect assumption that all VMAs
in a VM will be on the inactive list at the point last reference
to a context and VM is dropped.

This is not true because i915_gem_object_retire__read will not
put VMA on the inactive list until all activities on the object
in question (in all VMs) have been retired.

As a consequence, whether or not a context/VM will be destroyed
with its VMAs still on the active list, can depend on completely
unrelated activities using the same object from a different
context or engine.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92638
Testcase: igt/gem_request_retire/retire-vma-not-inactive
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michel Thierry <michel.thierry@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448025816-25584-1-git-send-email-tvrtko.ursulin@linux.intel.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
(cherry picked from commit 408952d4)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Commit e9f24d5f
Author: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Date:   Mon Oct 5 13:26:36 2015 +0100

    drm/i915: Clean up associated VMAs on context destruction

Added a warning based on an incorrect assumption that all VMAs
in a VM will be on the inactive list at the point last reference
to a context and VM is dropped.

This is not true because i915_gem_object_retire__read will not
put VMA on the inactive list until all activities on the object
in question (in all VMs) have been retired.

As a consequence, whether or not a context/VM will be destroyed
with its VMAs still on the active list, can depend on completely
unrelated activities using the same object from a different
context or engine.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92638
Testcase: igt/gem_request_retire/retire-vma-not-inactive
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michel Thierry <michel.thierry@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448025816-25584-1-git-send-email-tvrtko.ursulin@linux.intel.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

When register type safety happens, we can't just try to emit the
register itself to the ring. Instead we'll need to extract the
offset from it first. Add some convenience functions that will do
that.

v2: Convert MOCS setup too
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446672017-24497-20-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Since the beginning we have conflated the size of the global GTT with
that of the per-process context sizes. In recent times (gen8+), those
are no longer the same where the global GTT is limited to 2/4GiB but the
per-process GTT may be anything up to 256TiB. Userspace knows nothing of
this discrepancy and outside of one or two hacks, uses the getaperture
ioctl to determine the maximum size it can use. Let's leave that as
reporting the global GTT and use the context reporting method to
describe the per-process value (which naturally fallsback to reporting
the aliasing or global on older platforms, so userspace can always use
this method where available).

Testcase: igt/gem_userptr_blits/minor-normal-sync
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=90065Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

commit e9f24d5f
Author: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Date:   Mon Oct 5 13:26:36 2015 +0100

    drm/i915: Clean up associated VMAs on context destruction

Introduced a wrong assumption that all contexts have a ppgtt
instance. This is not true when full PPGTT is not active so
remove the WARN_ON_ONCE from the context cleanup code.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Prevent leaking VMAs and PPGTT VMs when objects are imported
via flink.

Scenario is that any VMAs created by the importer will be left
dangling after the importer exits, or destroys the PPGTT context
with which they are associated.

This is caused by object destruction not running when the
importer closes the buffer object handle due the reference held
by the exporter. This also leaks the VM since the VMA has a
reference on it.

In practice these leaks can be observed by stopping and starting
the X server on a kernel with fbcon compiled in. Every time
X server exits another VMA will be leaked against the fbcon's
frame buffer object.

Also on systems where flink buffer sharing is used extensively,
like Android, this leak has even more serious consequences.

This version is takes a general approach from the  earlier work
by Rafael Barbalho (drm/i915: Clean-up PPGTT on context
destruction) and tries to incorporate the subsequent discussion
between Chris Wilson and Daniel Vetter.

v2:

Removed immediate cleanup on object retire - it was causing a
recursive VMA unbind via i915_gem_object_wait_rendering. And
it is in fact not even needed since by definition context
cleanup worker runs only after the last context reference has
been dropped, hence all VMAs against the VM belonging to the
context are already on the inactive list.

v3:

Previous version could deadlock since VMA unbind waits on any
rendering on an object to complete. Objects can be busy in a
different VM which would mean that the cleanup loop would do
the wait with the struct mutex held.

This is an even simpler approach where we just unbind VMAs
without waiting since we know all VMAs belonging to this VM
are idle, and there is nothing in flight, at the point
context destructor runs.

v4:

Double underscore prefix for __915_vma_unbind_no_wait and a
commit message typo fix. (Michel Thierry)

Note that this is just a partial/interim fix since we have a bit a
fundamental issue with cleaning up, e.g.

https://bugs.freedesktop.org/show_bug.cgi?id=87729Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Testcase: igt/gem_ppgtt.c/flink-and-exit-vma-leak
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Rafael Barbalho <rafael.barbalho@intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
[danvet: Add a note that this isn't everything.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Broadwell hardware supports both ring buffer mode and execlist mode.
When i915 runs inside a VM with Intel GVT-g, we allow execlist mode
only.

The main reason of EXECLIST only is that GVT-g does not support the
dynamic mode switch between ring buffer mode and execlist mode when
running multiple virtual machines.

v2:
- Adjust the position of vgpu check in sanitize function (Joonas)
- Add vgpu error check in context initialization. (Joonas, Daniel)
Signed-off-by: NZhiyuan Lv <zhiyuan.lv@intel.com>
Signed-off-by: NZhi Wang <zhi.a.wang@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If we encounter an allocation failure during ppggt creation (trivial
even with 16Gib+ RAM!), we need to remove the dead context from the
fpriv->context_idr along with the references.

gem_exec_ctx: page allocation failure: order:0, mode:0x8004
CPU: 3 PID: 27272 Comm: gem_exec_ctx Tainted: G        W       4.2.0-rc5+ #37
 0000000000000000 ffff880086ff7a78 ffffffff816b947a ffff88041ed90038
 0000000000008004 ffff880086ff7b08 ffffffff8114b1a5 ffff880086ff7ac8
 ffffffff8108d848 0000000000000000 ffffffff81ce84b8 0000000000000000
Call Trace:
 [<ffffffff816b947a>] dump_stack+0x45/0x57
 [<ffffffff8114b1a5>] warn_alloc_failed+0xd5/0x120
 [<ffffffff8108d848>] ? __wake_up+0x48/0x60
 [<ffffffff8114e0ed>] __alloc_pages_nodemask+0x73d/0x8e0
 [<ffffffffc0472238>] ? i915_gem_execbuffer2+0x148/0x240 [i915]
 [<ffffffffc0474240>] __setup_page_dma+0x30/0x110 [i915]
 [<ffffffffc0477f61>] gen8_ppgtt_init+0x31/0x2f0 [i915]
 [<ffffffffc04785e0>] i915_ppgtt_init+0x30/0x80 [i915]
 [<ffffffffc0478928>] i915_ppgtt_create+0x48/0xc0 [i915]
 [<ffffffffc046c9c2>] i915_gem_create_context+0x1c2/0x390 [i915]
 [<ffffffffc046d9cb>] i915_gem_context_create_ioctl+0x5b/0xa0 [i915]

leading to an oops in i915_gem_context_close. Also note that this
benchmark should not be running out of memory in the first place...

Testcase: igt/benchmark/gem_exec_ctx -b create # ppgtt >= 2
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

[ 1572.417121] BUG: unable to handle kernel NULL pointer dereference at           (null)
[ 1572.421010] IP: [<ffffffffa00b2514>] ftrace_raw_event_i915_context+0x5d/0x70 [i915]
[ 1572.424970] PGD 1766a3067 PUD 1767a2067 PMD 0
[ 1572.428892] Oops: 0000 [#1] SMP
[ 1572.432787] Modules linked in: ipv6 dm_mod iTCO_wdt iTCO_vendor_support snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_controller snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_timer snd soundcore serio_raw pcspkr lpc_ich i2c_i801 mfd_core battery ac acpi_cpufreq i915 button video drm_kms_helper drm
[ 1572.441720] CPU: 2 PID: 18853 Comm: kworker/u8:0 Not tainted 4.0.0_kcloud_3f0360_20150429+ #588
[ 1572.446298] Workqueue: i915 i915_gem_retire_work_handler [i915]
[ 1572.450876] task: ffff880002f428f0 ti: ffff880035724000 task.ti: ffff880035724000
[ 1572.455557] RIP: 0010:[<ffffffffa00b2514>]  [<ffffffffa00b2514>] ftrace_raw_event_i915_context+0x5d/0x70 [i915]
[ 1572.460423] RSP: 0018:ffff880035727ce8  EFLAGS: 00010286
[ 1572.465262] RAX: ffff880073f1643c RBX: ffff880002da9058 RCX: ffff880073e5db40
[ 1572.470179] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff880035727ce8
[ 1572.475107] RBP: ffff88007bb11a00 R08: 0000000000000000 R09: 0000000000000000
[ 1572.480034] R10: 0000000000362200 R11: 0000000000000008 R12: 0000000000000000
[ 1572.484952] R13: ffff880035727d78 R14: ffff880002dc1c98 R15: ffff880002dc1dc8
[ 1572.489886] FS:  0000000000000000(0000) GS:ffff88017fd00000(0000) knlGS:0000000000000000
[ 1572.494883] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 1572.499859] CR2: 0000000000000000 CR3: 000000017572a000 CR4: 00000000001006e0
[ 1572.504842] Stack:
[ 1572.509834]  ffff88017b0090c0 ffff880073f16438 ffff880002da9058 ffff880073f1643c
[ 1572.514904]  0000000000000246 ffff880100000000 ffff88007bb11a00 ffff880002ddeb10
[ 1572.519985]  ffff8801759f79c0 ffffffffa0092ff0 0000000000000000 ffff88007bb11a00
[ 1572.525049] Call Trace:
[ 1572.530093]  [<ffffffffa0092ff0>] ? i915_gem_context_free+0xa8/0xc1 [i915]
[ 1572.535227]  [<ffffffffa009b969>] ? i915_gem_request_free+0x4e/0x50 [i915]
[ 1572.540347]  [<ffffffffa00b5533>] ? intel_execlists_retire_requests+0x14c/0x159 [i915]
[ 1572.545500]  [<ffffffffa009d9ea>] ? i915_gem_retire_requests+0x9d/0xeb [i915]
[ 1572.550664]  [<ffffffffa009dd8c>] ? i915_gem_retire_work_handler+0x4c/0x61 [i915]
[ 1572.555825]  [<ffffffff8104ca7f>] ? process_one_work+0x1b2/0x31d
[ 1572.560951]  [<ffffffff8104d278>] ? worker_thread+0x24d/0x339
[ 1572.566033]  [<ffffffff8104d02b>] ? cancel_delayed_work_sync+0xa/0xa
[ 1572.571140]  [<ffffffff81050b25>] ? kthread+0xce/0xd6
[ 1572.576191]  [<ffffffff81050a57>] ? kthread_create_on_node+0x162/0x162
[ 1572.581228]  [<ffffffff8179b3c8>] ? ret_from_fork+0x58/0x90
[ 1572.586259]  [<ffffffff81050a57>] ? kthread_create_on_node+0x162/0x162
[ 1572.591318] Code: de 48 89 e7 e8 09 4d 00 e1 48 85 c0 74 27 48 89 68 10 48 8b 55 38 48 89 e7 48 89 50 18 48 8b 55 10 48 8b 12 48 8b 12 48 8b 52 38 <8b> 12 89 50 08 e8 95 4d 00 e1 48 83 c4 30 5b 5d 41 5c c3 41 55
[ 1572.596981] RIP  [<ffffffffa00b2514>] ftrace_raw_event_i915_context+0x5d/0x70 [i915]
[ 1572.602464]  RSP <ffff880035727ce8>
[ 1572.607911] CR2: 0000000000000000

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=90112#c23Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Stolen gets trashed during hibernation, so storing contexts there
is not a very good idea. On my IVB machines this leads to a totally
dead GPU on resume. A reboot is required to resurrect it. So let's
not store contexts where they will get trampled.

This reverts commit 149c86e7.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Also clarify comments on context size that the extra state for
Resource Streamer is included.

v2: Don't remove the extended save/restore enabled for older
    platforms. (Ville)
    Use new MI_SET_CONTEXT defines for HSW RS save/restore state
    instead of extended save/restore. (Daniel)
Suggested-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NAbdiel Janulgue <abdiel.janulgue@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that everything above has been converted to use requests, intel_ring_begin()
can be updated to take a request instead of a ring. This also means that it no
longer needs to lazily allocate a request if no-one happens to have done it
earlier.

For: VIZ-5115
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NTomas Elf <tomas.elf@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Updated the various ring->flush() functions to take a request instead of a ring.
Also updated the tracer to include the request id.

For: VIZ-5115
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NTomas Elf <tomas.elf@intel.com>
[danvet: Rebase since I didn't merge the addition of req->uniq.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Updated the switch_mm() code paths to take a request instead of a ring. This
includes the myriad *_mm_switch functions themselves and a bunch of PDP related
helper functions.

v2: Rebased to newer tree.

For: VIZ-5115
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NTomas Elf <tomas.elf@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Updated mi_set_context() to take a request structure instead of a ring and
context pair.

For: VIZ-5115
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NTomas Elf <tomas.elf@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Converted i915_gem_l3_remap() to take a request structure instead of a ring.

For: VIZ-5115
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NTomas Elf <tomas.elf@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that everything above has been converted to use request structures, it is
possible to update the lower level move_to_active() functions to be request
based as well.

For: VIZ-5115
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NTomas Elf <tomas.elf@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that everything above has been converted to use requests, it is possible to
update init_context() to take a request pointer instead of a ring/context pair.

For: VIZ-5115
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NTomas Elf <tomas.elf@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Updated do_switch() to take a request pointer instead of a ring/context pair.

v2: Removed some overzealous req-> dereferencing.

For: VIZ-5115
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NTomas Elf <tomas.elf@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>