v2: (Imre)
- Access only subslices that are known to exist.
- Reset explicitly the MCR selector to slice/sub-slice ID 0 after the
  readout.
- Use the subslice INSTDONE bits for the hangcheck/subunits-stuck
  detection too.
- Take the uncore lock for the MCR-select/subslice-readout sequence.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1474379673-28326-2-git-send-email-imre.deak@intel.com

Consolidate the instdone logic so we can get a bit fancier. This patch also
removes the duplicated print of INSTDONE[0].

v2: (Imre)
- Rebased on top of hangcheck INSTDONE changes.
- Move all INSTDONE registers into a single struct, store it within the
  engine error struct during error capturing.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1474379673-28326-1-git-send-email-imre.deak@intel.com

Make the .hws_needs_physical the exception by switching the flag
on earlier platforms since they are fewer to support. Remove the flag on
later GPUs hardware since they all use GTT hws by default.

Switch the logic as well in the driver to reflect this change
Signed-off-by: NCarlos Santa <carlos.santa@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>

If we can't grab the breadcrumb's spinlock, possibly due to a driver
deadlock inside the waiters, ignore them. Like hangcheck, error
capturing must work no matter how the driver/GPU dies.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20160906073844.22561-1-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

In an effort to simplify things for a future push of dev_priv instead
of dev wherever possible, always take pdev via dev_priv where
feasible, eliminating the direct access from dev. Right now this
only eliminates a few cases of dev, but it also obviates that we pass
dev into a lot of functions where dev_priv would be the more obvious
choice.

v2: Fixed one more place missing in the previous patch set
Signed-off-by: NDavid Weinehall <david.weinehall@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160822103245.24069-5-david.weinehall@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

As io_mapping.h now always allocates the struct, we can avoid that
allocation and extra pointer dance by embedding the struct inside
drm_i915_private
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160819155428.1670-5-chris@chris-wilson.co.uk

In order to handle tiled partial GTT mmappings, we need to associate the
fence with an individual vma.

v2: A couple of silly drops replaced spotted by Joonas
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-21-chris@chris-wilson.co.uk

Just another useful register to inspect following a GPU hang.

v2: Remove partial decoding of RING_MODE to userspace, be consistent and
use GEN > 2 guards around RING_MODE everywhere.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471254551-25805-32-git-send-email-chris@chris-wilson.co.uk

There is no other state pertaining to the completed requests in the
hang, other than gleamed through the ringbuffer, so including the
expired requests in the list of outstanding requests simply adds noise.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471254551-25805-31-git-send-email-chris@chris-wilson.co.uk

It is useful when looking at captured error states to check the recorded
BBADDR register (the address of the last batchbuffer instruction loaded)
against the expected offset of the batch buffer, and so do a quick check
that (a) the capture is true or (b) HEAD hasn't wandered off into the
badlands.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471254551-25805-30-git-send-email-chris@chris-wilson.co.uk

Since contexts are not currently shared between userspace processes, we
have an exact correspondence between context creator and guilty batch
submitter. Therefore we can save some per-batch work by inspecting the
context->pid upon error instead. Note that we take the context's
creator's pid rather than the file's pid in order to better track fd
passed over sockets.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471254551-25805-29-git-send-email-chris@chris-wilson.co.uk

Treat the VMA as the primary struct responsible for tracking bindings
into the GPU's VM. That is we want to treat the VMA returned after we
pin an object into the VM as the cookie we hold and eventually release
when unpinning. Doing so eliminates the ambiguity in pinning the object
and then searching for the relevant pin later.

v2: Joonas' stylistic nitpicks, a fun rebase.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471254551-25805-27-git-send-email-chris@chris-wilson.co.uk

Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471254551-25805-25-git-send-email-chris@chris-wilson.co.uk

Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471254551-25805-23-git-send-email-chris@chris-wilson.co.uk

Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471254551-25805-19-git-send-email-chris@chris-wilson.co.uk

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

v2: Move the flush of the object back to before the first pin. We use
the am-I-bound? query to only have to check the flush on the first
bind and so avoid stalling on active rings.
Lots of little renames and small hoops.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471254551-25805-18-git-send-email-chris@chris-wilson.co.uk

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

v2: Formatting tweaks to debugfs output, restored some comments removed
in the next patch
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471254551-25805-15-git-send-email-chris@chris-wilson.co.uk

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

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

With execlists, we have context objects everywhere, not just RCS. So
store them for post-mortem debugging. This also has a secondary effect
of removing one more unsafe list iteration with using preserved state
from the hanging request. And now we can cross-reference the request's
context state with that loaded by the GPU.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471254551-25805-3-git-send-email-chris@chris-wilson.co.uk

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

v2: s/i/count_active/ (and similar)
    Rewrite label generation for "Buffers"
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471254551-25805-2-git-send-email-chris@chris-wilson.co.uk

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

In the previous commit, we moved the obj->tiling_mode out of a bitfield
and into its own integer so that we could safely use READ_ONCE(). Let us
now repair some of that damage by sharing the tiling_mode with its
companion, the fence stride.

v2: New magic
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470388464-28458-18-git-send-email-chris@chris-wilson.co.uk

In preparation to perform some magic to speed up i915_vma_pin(), which
is among the hottest of hot paths in execbuf, refactor all the bitfields
accessed by i915_vma_pin() into a single unified set of flags.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470324762-2545-16-git-send-email-chris@chris-wilson.co.uk

In the next few patches, the VMA pinning API is overhauled and to reduce
the churn we pull out the update to the accessors into a prep patch.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470324762-2545-14-git-send-email-chris@chris-wilson.co.uk

We use "list" to denote the list and "link" to denote an element on that
list. Rename request->list to match this idiom.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470293567-10811-14-git-send-email-chris@chris-wilson.co.uk

The future annotations will track the locking used for access to ensure
that it is always sufficient. We make the preparations now to present
the API ahead and to make sure that GCC can eliminate the unused
parameter.

Before:	6298417 3619610  696320 10614347         a1f64b vmlinux
After:	6298417 3619610  696320 10614347         a1f64b vmlinux
(with i915 builtin)
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470293567-10811-12-git-send-email-chris@chris-wilson.co.uk

In the future, we will want to add annotations to the i915_gem_active
struct. The API is thus expanded to hide direct access to the contents
of i915_gem_active and mediated instead through a number of helpers.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470293567-10811-11-git-send-email-chris@chris-wilson.co.uk

In the next patch, request tracking is made more generic and for that we
need a new expanded struct and to separate out the logic changes from
the mechanical churn, we split out the structure renaming into this
patch.

v2: Writer's block. Add some spiel about why we track requests.
v3: Now i915_gem_active.
v4: Now with i915_gem_active_set() for attaching to the active request.
v5: Use i915_gem_active_set() from inside the retirement handlers
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470293567-10811-10-git-send-email-chris@chris-wilson.co.uk

The state stored in this struct is not only the information about the
buffer object, but the ring used to communicate with the hardware. Using
buffer here is overly specific and, for me at least, conflates with the
notion of buffer objects themselves.

s/struct intel_ringbuffer/struct intel_ring/
s/enum intel_ring_hangcheck/enum intel_engine_hangcheck/
s/describe_ctx_ringbuf()/describe_ctx_ring()/
s/intel_ring_get_active_head()/intel_engine_get_active_head()/
s/intel_ring_sync_index()/intel_engine_sync_index()/
s/intel_ring_init_seqno()/intel_engine_init_seqno()/
s/ring_stuck()/engine_stuck()/
s/intel_cleanup_engine()/intel_engine_cleanup()/
s/intel_stop_engine()/intel_engine_stop()/
s/intel_pin_and_map_ringbuffer_obj()/intel_pin_and_map_ring()/
s/intel_unpin_ringbuffer()/intel_unpin_ring()/
s/intel_engine_create_ringbuffer()/intel_engine_create_ring()/
s/intel_ring_flush_all_caches()/intel_engine_flush_all_caches()/
s/intel_ring_invalidate_all_caches()/intel_engine_invalidate_all_caches()/
s/intel_ringbuffer_free()/intel_ring_free()/
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1469432687-22756-15-git-send-email-chris@chris-wilson.co.uk
Link: http://patchwork.freedesktop.org/patch/msgid/1470174640-18242-4-git-send-email-chris@chris-wilson.co.uk

Now that we have disambuigated ring and engine, we can use the clearer
and more consistent name for the intel_ringbuffer pointer in the
request.

@@
struct drm_i915_gem_request *r;
@@
- r->ringbuf
+ r->ring
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1469432687-22756-12-git-send-email-chris@chris-wilson.co.uk
Link: http://patchwork.freedesktop.org/patch/msgid/1470174640-18242-2-git-send-email-chris@chris-wilson.co.uk

Inside the error capture itself, we refer to not only the hardware
engine, its ringbuffer but also the capture state. Finding clear names
for each whilst avoiding mixing ring/intel_engine_cs is tricky. As a
compromise we keep using ering for the error capture.

v2: Use 'ee' locals for struct drm_i915_error_engine
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1469432687-22756-8-git-send-email-chris@chris-wilson.co.uk
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1469606850-28659-3-git-send-email-chris@chris-wilson.co.uk

Rather than recomputing whether semaphores are enabled, we can do that
computation once during early initialisation as the i915.semaphores
module parameter is now read-only.

s/i915_semaphores_is_enabled/i915.semaphores/

v2: Add the state to the debug dmesg as well
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1469005202-9659-10-git-send-email-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1469017917-15134-9-git-send-email-chris@chris-wilson.co.uk

dma-buf provides a generic fence class for interoperation between
drivers. Internally we use the request structure as a fence, and so with
only a little bit of interfacing we can rebase those requests on top of
dma-buf fences. This will allow us, in the future, to pass those fences
back to userspace or between drivers.

v2: The fence_context needs to be globally unique, not just unique to
this device.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1469002875-2335-4-git-send-email-chris@chris-wilson.co.uk

Since drm_i915_private is now a subclass of drm_device we do not need to
chase the drm_i915_private->dev backpointer and can instead simply
access drm_i915_private->drm directly.

   text	   data	    bss	    dec	    hex	filename
1068757	   4565	    416	1073738	 10624a	drivers/gpu/drm/i915/i915.ko
1066949	   4565	    416	1071930	 105b3a	drivers/gpu/drm/i915/i915.ko

Created by the coccinelle script:
@@
struct drm_i915_private *d;
identifier i;
@@
(
- d->dev->i
+ d->drm.i
|
- d->dev
+ &d->drm
)

and for good measure the dev_priv->dev backpointer was removed entirely.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467711623-2905-4-git-send-email-chris@chris-wilson.co.uk

As we only ever keep the first error state around, we can avoid some
work that can be quite intrusive if we don't record the error the second
time around. This does move the race whereby the user could discard one
error state as the second is being captured, but that race exists in the
current code and we hope that recapturing error state is only done for
debugging.

Note that as we discard the error state for simulated errors, igt that
exercise error capture continue to function.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1467618513-4966-3-git-send-email-chris@chris-wilson.co.ukReviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>

Since we now subclass struct drm_device, we can save pointer dances by
noting the equivalence of struct drm_device and struct drm_i915_private,
i.e. by using to_i915().

   text    data     bss     dec     hex filename
1073824    4562     416 1078802  107612 drivers/gpu/drm/i915/i915.ko
1068976    4562     416 1073954  106322 drivers/gpu/drm/i915/i915.ko

Created by the coccinelle script:

@@
expression E;
identifier p;
@@
- struct drm_i915_private *p = E->dev_private;
+ struct drm_i915_private *p = to_i915(E);
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467628477-25379-1-git-send-email-chris@chris-wilson.co.uk

igt likes to inject GPU hangs into its command streams. However, as we
expect these hangs, we don't actually want them recorded in the dmesg
output or stored in the i915_error_state (usually). To accommodate this
allow userspace to set a flag on the context that any hang emanating
from that context will not be recorded. We still do the error capture
(otherwise how do we find the guilty context and know its intent?) as
part of the reason for random GPU hang injection is to exercise the race
conditions between the error capture and normal execution.

v2: Split out the request->ringbuf error capture changes.
v3: Move the flag defines next to the intel_context->flags definition
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467616119-4093-9-git-send-email-chris@chris-wilson.co.uk

The request tells us where to read the ringbuf from, so use that
information to simplify the error capture. If no request was active at
the time of the hang, the ring is idle and there is no information
inside the ring pertaining to the hang.

Note carefully that this will reduce the amount of information stored in
the error state - any ring without an active request will not be
recorded.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467616119-4093-8-git-send-email-chris@chris-wilson.co.uk

smatch complains:
	drivers/gpu/drm/i915/i915_gpu_error.c:503 i915_error_state_to_str()
	warn: inconsistent indenting
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1467470166-31717-4-git-send-email-chris@chris-wilson.co.ukReviewed-by: NMatthew Auld <matthew.auld@intel.com>

By using the same address for storing the HWS on every platform, we can
remove the platform specific vfuncs and reduce the get-seqno routine to
a single read of a cached memory location.

v2: Fix semaphore_passed() to look at the signaling engine (not the
waiter's)
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467390209-3576-8-git-send-email-chris@chris-wilson.co.uk