We only need the active reference to keep the object alive after the
handle has been deleted (so as to prevent a synchronous gem_close). Why
then pay the price of a kref on every execbuf when we can insert that
final active ref just in time for the handle deletion?
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/20161028125858.23563-6-chris@chris-wilson.co.uk

Our low-level wait routine has evolved from our generic wait interface
that handled unlocked, RPS boosting, waits with time tracking. If we
push our GEM fence tracking to use reservation_objects (required for
handling multiple timelines), we lose the ability to pass the required
information down to i915_wait_request(). However, if we push the extra
functionality from i915_wait_request() to the individual callsites
(i915_gem_object_wait_rendering and i915_gem_wait_ioctl) that make use
of those extras, we can both simplify our low level wait and prepare for
extending the GEM interface for use of reservation_objects.

v2: Rewrite i915_wait_request() kerneldocs
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161028125858.23563-4-chris@chris-wilson.co.uk

The throttle-ioctl never touches the struct_mutex. It does, however, as
part of its ABI report whether the hardware is terminally wedged. For
that purposes, it only has to report the current state and not incur the
cost of checking/waiting every invocation, as we do not have to wait for
a reset before waiting on a request to ensure completion (that is baked
into the wait request implementation).
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/20161028125858.23563-3-chris@chris-wilson.co.uk

We will need to wait on DMA completion (as signaled via struct fence)
before executing our i915_gem_request. Therefore we want to expose a
method for adding the await on the fence itself to the request.

v2: Add a comment detailing a failure to handle a signal-on-any
fence-array.
v3: Pretend that magic numbers don't exist.
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/20161028125858.23563-1-chris@chris-wilson.co.uk

Objects can have multiple VMAs used for display in which
case assertion that objects must not be pinned for display
more times than the current VMA is incorrect.

v2: Commit message update. (Chris Wilson)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Fixes: 058d88c4 ("drm/i915: Track pinned VMA")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1477413635-3876-1-git-send-email-tvrtko.ursulin@linux.intel.com

We do not need to set up a fence for the rotated view.

Display does not need it and no one can access it.

v2: Move code to __i915_vma_set_map_and_fenceable. (Chris Wilson)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Fixes: 05a20d09 ("drm/i915: Move map-and-fenceable tracking to the VMA")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

As well as knowing when the error occurred, it is more interesting to me
to know how long after booting the error occurred, and for good measure
record the time since last hw initialisation.
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/20161025121602.1457-1-chris@chris-wilson.co.uk

At the moment, we have dependency on the RPM as a barrier itself in both
i915_gem_release_all_mmaps() and i915_gem_restore_fences().
i915_gem_restore_fences() is also called along !runtime pm paths, but we
can move the markup of lost fences alongside releasing the mmaps into a
common i915_gem_runtime_suspend(). This has the advantage of locating
all the tricky barrier dependencies into one location.

v2: Just mark the fence as invalid (fence->dirty) so that upon waking we
will be sure to clear the fence after use, or restore it to the correct
value before use. This makes sure that if the fence is left intact
across the sleep, we do not leave it pointing to a region of GTT for the
next unsuspecting user.
Suggested-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Imre Deak <imre.deak@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161024124218.18252-5-chris@chris-wilson.co.uk

Now that we have reduced the access to the list to either (a) under the
struct_mutex whilst holding the RPM wakeref (so that concurrent writers to
the list are serialised by struct_mutex) and (b) under the atomic
runtime suspend (which cannot run concurrently with any other accessor due
to the atomic nature of the runtime suspend) we can remove the extra
locking around the list itself.
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/20161024124218.18252-3-chris@chris-wilson.co.uk

We can remove the false coupling between RPM and struct mutex by the
observation that we can use the RPM wakeref as the barrier around user
mmap access. That is as we tear down the user's PTE atomically from
within rpm suspend and then to fault in new PTE requires the rpm
wakeref, means that no user access is possible through those PTE without
RPM being awake. Having made that observation, we can then remove the
presumption of having to take rpm outside of struct_mutex and so allow
fine grained acquisition of a wakeref around hw access rather than
having to remember to acquire the wakeref early on.

v2: Rejig placement of the new intel_runtime_pm_get() to be as tight
as possible around the GTT pread/pwrite.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161024124218.18252-2-chris@chris-wilson.co.uk

We want to decouple RPM and struct_mutex, but currently RPM has to walk
the list of bound objects and remove userspace mmapping before we
suspend (otherwise userspace may continue to access the GTT whilst it is
powered down). This currently requires the struct_mutex to walk the
bound_list, but if we move that to a separate list and lock we can take
the first step towards removing the struct_mutex.

v2: Split runtime suspend unmapping vs regular unmapping, to make the
locking (and barriers) clearer. Add the object to the userfault_list
prior to inserting the first PTE, the race between add/revoke depends
upon struct_mutex for regular unmappings and rpm for runtime-suspend.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> #v1
Link: http://patchwork.freedesktop.org/patch/msgid/20161024124218.18252-1-chris@chris-wilson.co.uk

The scattergather list uses a 32bit size counter, we should avoid
exceeding it.

v2: Also we should use unsigned int to match sg->length.

Fixes: 871dfbd6 ("drm/i915: Allow compaction upto SWIOTLB max segment size")
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/20161018120251.25043-3-chris@chris-wilson.co.uk

In many places, we try to count pages using a 32 bit integer. That
implies if we are asked to create an object larger than 43bits, we will
subtly crash much later. Catch this on the boundary, and add a warning
to remind ourselves later on our exabyte systems.
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/20161018120251.25043-2-chris@chris-wilson.co.uk

Internally we allow for using more objects than a single process can
allocate, i.e. we allow for a 64bit GPU address space even on a 32bit
system. Using size_t may oveerflow.
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/20161018120251.25043-1-chris@chris-wilson.co.uk

We never used any invalid ptes, those were put in place for
a possibility of doing gpu faults. However our batchbuffers are not
restricted in length, so everything needs to be pointing to something
and thus out-of-bounds is pointing to scratch.

Remove the valid flag as it is always true.

v2: Expand commit msg, patch reorder (Mika)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michel Thierry <michel.thierry@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NMichał Winiarski <michal.winiarski@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1476360162-24062-1-git-send-email-michal.winiarski@intel.com

Saves 1416 bytes of .rodata strings.

v2: Add parantheses around dev_priv. (Ville Syrjala)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NDavid Weinehall <david.weinehall@linux.intel.com>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: NJani Nikula <jani.nikula@linux.intel.com>
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476352990-2504-1-git-send-email-tvrtko.ursulin@linux.intel.com

Saves 2432 bytes of .rodata strings.

v2: Add parantheses around dev_priv. (Ville Syrjala)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NDavid Weinehall <david.weinehall@linux.intel.com>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: NJani Nikula <jani.nikula@linux.intel.com>
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>

Saves 1808 bytes of .rodata strings.

v2: Add parantheses around dev_priv. (Ville Syrjala)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NDavid Weinehall <david.weinehall@linux.intel.com>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: NJani Nikula <jani.nikula@linux.intel.com>
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>

Saves 848 bytes of .rodata strings.

v2: Add parantheses around dev_priv. (Ville Syrjala)
v3: Rebase.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NDavid Weinehall <david.weinehall@linux.intel.com>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: NJani Nikula <jani.nikula@linux.intel.com>
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>

Saves 4472 bytes of .rodata strings.

v2: Add parantheses around dev_priv. (Ville Syrjala)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NDavid Weinehall <david.weinehall@linux.intel.com>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: NJani Nikula <jani.nikula@linux.intel.com>
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>

This saves 1872 bytes of .rodata strings.

v2:
 * Rebase.
 * Add parantheses around dev_priv. (Ville Syrjala)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NDavid Weinehall <david.weinehall@linux.intel.com>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: NJani Nikula <jani.nikula@linux.intel.com>
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>

With the possibility of addition of many more number of rings in future,
the drm_i915_private structure could bloat as an array, of type
intel_engine_cs, is embedded inside it.
	struct intel_engine_cs engine[I915_NUM_ENGINES];
Though this is still fine as generally there is only a single instance of
drm_i915_private structure used, but not all of the possible rings would be
enabled or active on most of the platforms. Some memory can be saved by
allocating intel_engine_cs structure only for the enabled/active engines.
Currently the engine/ring ID is kept static and dev_priv->engine[] is simply
indexed using the enums defined in intel_engine_id.
To save memory and continue using the static engine/ring IDs, 'engine' is
defined as an array of pointers.
	struct intel_engine_cs *engine[I915_NUM_ENGINES];
dev_priv->engine[engine_ID] will be NULL for disabled engine instances.

There is a text size reduction of 928 bytes, from 1028200 to 1027272, for
i915.o file (but for i915.ko file text size remain same as 1193131 bytes).

v2:
- Remove the engine iterator field added in drm_i915_private structure,
  instead pass a local iterator variable to the for_each_engine**
  macros. (Chris)
- Do away with intel_engine_initialized() and instead directly use the
  NULL pointer check on engine pointer. (Chris)

v3:
- Remove for_each_engine_id() macro, as the updated macro for_each_engine()
  can be used in place of it. (Chris)
- Protect the access to Render engine Fault register with a NULL check, as
  engine specific init is done later in Driver load sequence.

v4:
- Use !!dev_priv->engine[VCS] style for the engine check in getparam. (Chris)
- Kill the superfluous init_engine_lists().

v5:
- Cleanup the intel_engines_init() & intel_engines_setup(), with respect to
  allocation of intel_engine_cs structure. (Chris)

v6:
- Rebase.

v7:
- Optimize the for_each_engine_masked() macro. (Chris)
- Change the type of 'iter' local variable to enum intel_engine_id. (Chris)
- Rebase.

v8: Rebase.

v9: Rebase.

v10:
- For index calculation use engine ID instead of pointer based arithmetic in
  intel_engine_sync_index() as engine pointers are not contiguous now (Chris)
- For appropriateness, rename local enum variable 'iter' to 'id'. (Joonas)
- Use for_each_engine macro for cleanup in intel_engines_init() and remove
  check for NULL engine pointer in cleanup() routines. (Joonas)

v11: Rebase.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NAkash Goel <akash.goel@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476378888-7372-1-git-send-email-akash.goel@intel.com

If the user requests a mappable binding to the global GTT, we will first
unbind an existing mapping if it doesn't match. We will unbind even if
there is no possibility that the object can fit in the mappable
aperture. This may lead to a ping-pong migration of the object, for
example igt/gem_exec_big.

v2: Comment upon the reasoning, or lack thereof!, behind the choice of
magic numbers.

Testcase: igt/gem_exec_big
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20161013085504.30705-1-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com

Currently resuming on HSW from S3 pm_test/devices state leads to an
unrecoverable GPU hang. Resetting the GPU during suspend fixes this. For
a full S3 cycle this change only means the reset happens earlier (before
reaching S3). For S4 the reset will happen now both during the freeze
and quiesce phases, which is a benefit since it will guarantee that the
GPU is idle before creating and loading the hibernation image.

Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Suggested-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1476283597-580-1-git-send-email-imre.deak@intel.com

If we want to know how many pages a VMA spans, we can use vma_pages() to
find out. We have one such invocation inside our faulthandler, so
convert it. (We have two other that want the size in bytes rather than
pages, food for future thought.)
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20161011090656.29554-1-chris@chris-wilson.co.ukReviewed-by: NMatthew Auld <matthew.auld@intel.com>

commit 1625e7e5 ("drm/i915: make compact dma scatter lists creation
work with SWIOTLB backend") took a heavy handed approach to undo the
scatterlist compaction in the face of SWIOTLB. (The compaction hit a bug
whereby we tried to pass a segment larger than SWIOTLB could handle.) We
can be a little more intelligent and try compacting the scatterlist up
to the maximum SWIOTLB segment size (when using SWIOTLB).

v2: Tidy sg_mark_end() and cpp
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
CC: Imre Deak <imre.deak@intel.com>
CC: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161011082021.14606-2-chris@chris-wilson.co.uk

When we notice the system under memory pressure, we try to evict some
driver pages before asking the VM to shrink all caches. As a final step
in that process, we tried to evict everything, including active buffers.
This is harming ourselves, and we can mix shrinking all caches as well
as our residual buffers (after the first pass of trying to shrink just
our own buffers).
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMichał Winiarski <michal.winiarski@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161011082021.14606-1-chris@chris-wilson.co.uk

The conflict resolution of v4.8-rc8 backmerge to drm-next pulled back in
a few lines of dead code due to the code movement around
i915_gem_reset(), fix that up.

Fixes: ca09fb9f ("Merge tag 'v4.8-rc8' into drm-next")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@gmail.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161010125017.23911-1-chris@chris-wilson.co.uk

At the point of creating the hibernation image, the runtime power manage
core is disabled - and using the rpm functions triggers a warn.
i915_gem_shrink_all() tries to unbind objects, which requires device
access and so tries to how an rpm reference triggering a warning:

[   44.235420] ------------[ cut here ]------------
[   44.235424] WARNING: CPU: 2 PID: 2199 at drivers/gpu/drm/i915/intel_runtime_pm.c:2688 intel_runtime_pm_get_if_in_use+0xe6/0xf0
[   44.235426] WARN_ON_ONCE(ret < 0)
[   44.235445] Modules linked in: ctr ccm arc4 rt2800usb rt2x00usb rt2800lib rt2x00lib crc_ccitt mac80211 cmac cfg80211 btusb rfcomm bnep btrtl btbcm btintel bluetooth dcdbas x86_pkg_temp_thermal intel_powerclamp coretemp snd_hda_codec_realtek crct10dif_pclmul crc32_pclmul ghash_clmulni_intel snd_hda_codec_generic aesni_intel snd_hda_codec_hdmi aes_x86_64 lrw gf128mul snd_hda_intel glue_helper ablk_helper cryptd snd_hda_codec hid_multitouch joydev snd_hda_core binfmt_misc i2c_hid serio_raw snd_pcm acpi_pad snd_timer snd i2c_designware_platform 8250_dw nls_iso8859_1 i2c_designware_core lpc_ich mfd_core soundcore usbhid hid psmouse ahci libahci
[   44.235447] CPU: 2 PID: 2199 Comm: kworker/u8:8 Not tainted 4.8.0-rc5+ #130
[   44.235447] Hardware name: Dell Inc. XPS 13 9343/0310JH, BIOS A07 11/11/2015
[   44.235450] Workqueue: events_unbound async_run_entry_fn
[   44.235453]  0000000000000000 ffff8801b2f7fb98 ffffffff81306c2f ffff8801b2f7fbe8
[   44.235454]  0000000000000000 ffff8801b2f7fbd8 ffffffff81056c01 00000a801f50ecc0
[   44.235456]  ffff88020ce50000 ffff88020ce59b60 ffffffff81a60b5c ffffffff81414840
[   44.235456] Call Trace:
[   44.235459]  [<ffffffff81306c2f>] dump_stack+0x4d/0x6e
[   44.235461]  [<ffffffff81056c01>] __warn+0xd1/0xf0
[   44.235464]  [<ffffffff81414840>] ? i915_pm_suspend_late+0x30/0x30
[   44.235465]  [<ffffffff81056c6f>] warn_slowpath_fmt+0x4f/0x60
[   44.235468]  [<ffffffff814e73ce>] ? pm_runtime_get_if_in_use+0x6e/0xa0
[   44.235469]  [<ffffffff81433526>] intel_runtime_pm_get_if_in_use+0xe6/0xf0
[   44.235471]  [<ffffffff81458a26>] i915_gem_shrink+0x306/0x360
[   44.235473]  [<ffffffff81343fd4>] ? pci_platform_power_transition+0x24/0x90
[   44.235475]  [<ffffffff81414840>] ? i915_pm_suspend_late+0x30/0x30
[   44.235476]  [<ffffffff81458dfb>] i915_gem_shrink_all+0x1b/0x30
[   44.235478]  [<ffffffff814560b3>] i915_gem_freeze_late+0x33/0x90
[   44.235479]  [<ffffffff81414877>] i915_pm_freeze_late+0x37/0x40
[   44.235481]  [<ffffffff814e9b8e>] dpm_run_callback+0x4e/0x130
[   44.235483]  [<ffffffff814ea5db>] __device_suspend_late+0xdb/0x1f0
[   44.235484]  [<ffffffff814ea70f>] async_suspend_late+0x1f/0xa0
[   44.235486]  [<ffffffff81077557>] async_run_entry_fn+0x37/0x150
[   44.235488]  [<ffffffff8106f518>] process_one_work+0x148/0x3f0
[   44.235490]  [<ffffffff8106f8eb>] worker_thread+0x12b/0x490
[   44.235491]  [<ffffffff8106f7c0>] ? process_one_work+0x3f0/0x3f0
[   44.235492]  [<ffffffff81074d09>] kthread+0xc9/0xe0
[   44.235495]  [<ffffffff816e257f>] ret_from_fork+0x1f/0x40
[   44.235496]  [<ffffffff81074c40>] ? kthread_park+0x60/0x60
[   44.235497] ---[ end trace e438706b97c7f132 ]---

Alternatively, to actually shrink everything we have to do so slightly
earlier in the hibernation process.

To keep lockdep silent, we need to take struct_mutex for the shrinker
even though we know that we are the only user during the freeze.

Fixes: 7aab2d53 ("drm/i915: Shrink objects prior to hibernation")
Signed-off-by: NChris Wilson <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/20160921135108.29574-2-chris@chris-wilson.co.uk
(cherry picked from commit 6a800eab)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Following commit 821ed7df ("drm/i915: Update reset path to fix
incomplete requests") we no longer mark the context as lost on reset as
we keep the requests (and contexts) alive. However, RPS remains reset
and we need to restore the current state to match the in-flight
requests.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97824
Fixes: 821ed7df ("drm/i915: Update reset path to fix incomplete requests")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Arun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160921135108.29574-1-chris@chris-wilson.co.uk
(cherry picked from commit f2a91d1a)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Check that there was not a late recovery between us declaring the GPU
hung and processing the reset. If the GPU did recover by itself, let the
request remain on the active list and see if it hangs again!
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161004201132.21801-5-chris@chris-wilson.co.uk

Whilst we reset the GPU, we want to prevent execlists from submitting
new work (which it does via an interrupt handler). To achieve this we
disable the irq (and drain the irq tasklet) around the reset. When we
enable it again afters, the interrupt queue should be empty and we can
reinitialise from a known state without fear of the tasklet running
concurrently.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161004201132.21801-4-chris@chris-wilson.co.uk

* the only remaining callers of "short" fault-ins are just as happy with generic
variants (both in lib/iov_iter.c); switch them to multipage variants, kill the
"short" ones
* rename the multipage variants to now available plain ones.
* get rid of compat macro defining iov_iter_fault_in_multipage_readable by
expanding it in its only user.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

At the point of creating the hibernation image, the runtime power manage
core is disabled - and using the rpm functions triggers a warn.
i915_gem_shrink_all() tries to unbind objects, which requires device
access and so tries to how an rpm reference triggering a warning:

[   44.235420] ------------[ cut here ]------------
[   44.235424] WARNING: CPU: 2 PID: 2199 at drivers/gpu/drm/i915/intel_runtime_pm.c:2688 intel_runtime_pm_get_if_in_use+0xe6/0xf0
[   44.235426] WARN_ON_ONCE(ret < 0)
[   44.235445] Modules linked in: ctr ccm arc4 rt2800usb rt2x00usb rt2800lib rt2x00lib crc_ccitt mac80211 cmac cfg80211 btusb rfcomm bnep btrtl btbcm btintel bluetooth dcdbas x86_pkg_temp_thermal intel_powerclamp coretemp snd_hda_codec_realtek crct10dif_pclmul crc32_pclmul ghash_clmulni_intel snd_hda_codec_generic aesni_intel snd_hda_codec_hdmi aes_x86_64 lrw gf128mul snd_hda_intel glue_helper ablk_helper cryptd snd_hda_codec hid_multitouch joydev snd_hda_core binfmt_misc i2c_hid serio_raw snd_pcm acpi_pad snd_timer snd i2c_designware_platform 8250_dw nls_iso8859_1 i2c_designware_core lpc_ich mfd_core soundcore usbhid hid psmouse ahci libahci
[   44.235447] CPU: 2 PID: 2199 Comm: kworker/u8:8 Not tainted 4.8.0-rc5+ #130
[   44.235447] Hardware name: Dell Inc. XPS 13 9343/0310JH, BIOS A07 11/11/2015
[   44.235450] Workqueue: events_unbound async_run_entry_fn
[   44.235453]  0000000000000000 ffff8801b2f7fb98 ffffffff81306c2f ffff8801b2f7fbe8
[   44.235454]  0000000000000000 ffff8801b2f7fbd8 ffffffff81056c01 00000a801f50ecc0
[   44.235456]  ffff88020ce50000 ffff88020ce59b60 ffffffff81a60b5c ffffffff81414840
[   44.235456] Call Trace:
[   44.235459]  [<ffffffff81306c2f>] dump_stack+0x4d/0x6e
[   44.235461]  [<ffffffff81056c01>] __warn+0xd1/0xf0
[   44.235464]  [<ffffffff81414840>] ? i915_pm_suspend_late+0x30/0x30
[   44.235465]  [<ffffffff81056c6f>] warn_slowpath_fmt+0x4f/0x60
[   44.235468]  [<ffffffff814e73ce>] ? pm_runtime_get_if_in_use+0x6e/0xa0
[   44.235469]  [<ffffffff81433526>] intel_runtime_pm_get_if_in_use+0xe6/0xf0
[   44.235471]  [<ffffffff81458a26>] i915_gem_shrink+0x306/0x360
[   44.235473]  [<ffffffff81343fd4>] ? pci_platform_power_transition+0x24/0x90
[   44.235475]  [<ffffffff81414840>] ? i915_pm_suspend_late+0x30/0x30
[   44.235476]  [<ffffffff81458dfb>] i915_gem_shrink_all+0x1b/0x30
[   44.235478]  [<ffffffff814560b3>] i915_gem_freeze_late+0x33/0x90
[   44.235479]  [<ffffffff81414877>] i915_pm_freeze_late+0x37/0x40
[   44.235481]  [<ffffffff814e9b8e>] dpm_run_callback+0x4e/0x130
[   44.235483]  [<ffffffff814ea5db>] __device_suspend_late+0xdb/0x1f0
[   44.235484]  [<ffffffff814ea70f>] async_suspend_late+0x1f/0xa0
[   44.235486]  [<ffffffff81077557>] async_run_entry_fn+0x37/0x150
[   44.235488]  [<ffffffff8106f518>] process_one_work+0x148/0x3f0
[   44.235490]  [<ffffffff8106f8eb>] worker_thread+0x12b/0x490
[   44.235491]  [<ffffffff8106f7c0>] ? process_one_work+0x3f0/0x3f0
[   44.235492]  [<ffffffff81074d09>] kthread+0xc9/0xe0
[   44.235495]  [<ffffffff816e257f>] ret_from_fork+0x1f/0x40
[   44.235496]  [<ffffffff81074c40>] ? kthread_park+0x60/0x60
[   44.235497] ---[ end trace e438706b97c7f132 ]---

Alternatively, to actually shrink everything we have to do so slightly
earlier in the hibernation process.

To keep lockdep silent, we need to take struct_mutex for the shrinker
even though we know that we are the only user during the freeze.

Fixes: 7aab2d53 ("drm/i915: Shrink objects prior to hibernation")
Signed-off-by: NChris Wilson <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/20160921135108.29574-2-chris@chris-wilson.co.uk

Following commit 821ed7df ("drm/i915: Update reset path to fix
incomplete requests") we no longer mark the context as lost on reset as
we keep the requests (and contexts) alive. However, RPS remains reset
and we need to restore the current state to match the in-flight
requests.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97824
Fixes: 821ed7df ("drm/i915: Update reset path to fix incomplete requests")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Arun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160921135108.29574-1-chris@chris-wilson.co.uk

In an attempt to keep the hibernation image as same as possible, let's
try and discard any unwanted pages and our own page arrays.
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/20160909190218.16831-1-chris@chris-wilson.co.uk

We are about to specialize object synchronisation to enable nonblocking
execbuf submission. First we make a copy of the current object
synchronisation for execbuffer. The general i915_gem_object_sync() will
be removed following the removal of CS flips in the near future.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJohn Harrison <john.c.harrison@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160909131201.16673-16-chris@chris-wilson.co.uk

Drive final request submission from a callback from the fence. This way
the request is queued until all dependencies are resolved, at which
point it is handed to the backend for queueing to hardware. At this
point, no dependencies are set on the request, so the callback is
immediate.

A side-effect of imposing a heavier-irqsafe spinlock for execlist
submission is that we lose the softirq enabling after scheduling the
execlists tasklet. To compensate, we manually kickstart the softirq by
disabling and enabling the bh around the fence signaling.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NJohn Harrison <john.c.harrison@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160909131201.16673-14-chris@chris-wilson.co.uk

Update reset path in preparation for engine reset which requires
identification of incomplete requests and associated context and fixing
their state so that engine can resume correctly after reset.

The request that caused the hang will be skipped and head is reset to the
start of breadcrumb. This allows us to resume from where we left-off.
Since this request didn't complete normally we also need to cleanup elsp
queue manually. This is vital if we employ nonblocking request
submission where we may have a web of dependencies upon the hung request
and so advancing the seqno manually is no longer trivial.

ABI: gem_reset_stats / DRM_IOCTL_I915_GET_RESET_STATS

We change the way we count pending batches. Only the active context
involved in the reset is marked as either innocent or guilty, and not
mark the entire world as pending. By inspection this only affects
igt/gem_reset_stats (which assumes implementation details) and not
piglit.

ARB_robustness gives this guide on how we expect the user of this
interface to behave:

 * Provide a mechanism for an OpenGL application to learn about
   graphics resets that affect the context.  When a graphics reset
   occurs, the OpenGL context becomes unusable and the application
   must create a new context to continue operation. Detecting a
   graphics reset happens through an inexpensive query.

And with regards to the actual meaning of the reset values:

   Certain events can result in a reset of the GL context. Such a reset
   causes all context state to be lost. Recovery from such events
   requires recreation of all objects in the affected context. The
   current status of the graphics reset state is returned by

	enum GetGraphicsResetStatusARB();

   The symbolic constant returned indicates if the GL context has been
   in a reset state at any point since the last call to
   GetGraphicsResetStatusARB. NO_ERROR indicates that the GL context
   has not been in a reset state since the last call.
   GUILTY_CONTEXT_RESET_ARB indicates that a reset has been detected
   that is attributable to the current GL context.
   INNOCENT_CONTEXT_RESET_ARB indicates a reset has been detected that
   is not attributable to the current GL context.
   UNKNOWN_CONTEXT_RESET_ARB indicates a detected graphics reset whose
   cause is unknown.

The language here is explicit in that we must mark up the guilty batch,
but is loose enough for us to relax the innocent (i.e. pending)
accounting as only the active batches are involved with the reset.

In the future, we are looking towards single engine resetting (with
minimal locking), where it seems inappropriate to mark the entire world
as innocent since the reset occurred on a different engine. Reducing the
information available means we only have to encounter the pain once, and
also reduces the information leaking from one context to another.

v2: Legacy ringbuffer submission required a reset following hibernation,
or else we restore stale values to the RING_HEAD and walked over
stolen garbage.

v3: GuC requires replaying the requests after a reset.

v4: Restore engine IRQ after reset (so waiters will be woken!)
    Rearm hangcheck if resetting with a waiter.

Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Arun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160909131201.16673-13-chris@chris-wilson.co.uk

In the next patch we want to handle reset directly by a locked waiter in
order to avoid issues with returning before the reset is handled. To
handle the reset, we must first know whether we hold the struct_mutex.
If we do not hold the struct_mtuex we can not perform the reset, but we do
not block the reset worker either (and so we can just continue to wait for
request completion) - otherwise we must relinquish the mutex.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160909131201.16673-10-chris@chris-wilson.co.uk