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

Now that we have (near) universal GPU recovery code, we can inject a
real hang from userspace and not need any fakery. Not only does this
mean that the testing is far more realistic, but we can simplify the
kernel in the process.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467616119-4093-7-git-send-email-chris@chris-wilson.co.uk

The retire worker is a low frequency task that makes sure we retire
outstanding requests if userspace is being lax. We only need to start it
once as it remains active until the GPU is idle, so do a cheap test
before the more expensive queue_work(). A consequence of this is that we
need correct locking in the worker to make the hot path of request
submission cheap. To keep the symmetry and keep hangcheck strictly bound
by the GPU's wakelock, we move the cancel_sync(hangcheck) to the idle
worker before dropping the wakelock.

v2: Guard against RCU fouling the breadcrumbs bottom-half whilst we kick
the waiter.
v3: Remove the wakeref assertion squelching (now we hold a wakeref for
the hangcheck, any rpm error there is genuine).
v4: To prevent excess work when retiring requests, we split the busy
flag into two, a boolean to denote whether we hold the wakeref and a
bitmask of active engines.
v5: Reorder cancelling hangcheck upon idling to avoid a race where we
might cancel a hangcheck after being preempted by a new task
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
References: https://bugs.freedesktop.org/show_bug.cgi?id=88437Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467616119-4093-1-git-send-email-chris@chris-wilson.co.uk

Under the assumption that enabling signaling will be a frequent
operation, lets preallocate our attachments for signaling inside the
(rather large) request struct (and so benefiting from the slab cache).

v2: Convert from void * to more meaningful names and types.
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/1467390209-3576-17-git-send-email-chris@chris-wilson.co.uk

If we convert the tracing over from direct use of ring->irq_get() and
over to the breadcrumb infrastructure, we only have a single user of the
ring->irq_get and so we will be able to simplify the driver routines
(eliminating the redundant validation and irq refcounting).

Process context is preferred over softirq (or even hardirq) for a couple
of reasons:

 - we already utilize process context to have fast wakeup of a single
   client (i.e. the client waiting for the GPU inspects the seqno for
   itself following an interrupt to avoid the overhead of a context
   switch before it returns to userspace)

 - engine->irq_seqno() is not suitable for use from an softirq/hardirq
   context as we may require long waits (100-250us) to ensure the seqno
   write is posted before we read it from the CPU

A signaling framework is a requirement for enabling dma-fences.

v2: Move to a signaling framework based upon the waiter.
v3: Track the first-signal to avoid having to walk the rbtree everytime.
v4: Mark the signaler thread as RT priority to reduce latency in the
indirect wakeups.
v5: Make failure to allocate the thread fatal.
v6: Rename kthreads to i915/signal:%u
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/1467390209-3576-16-git-send-email-chris@chris-wilson.co.uk

If we flag the seqno as potentially stale upon receiving an interrupt,
we can use that information to reduce the frequency that we apply the
heavyweight coherent seqno read (i.e. if we wake up a chain of waiters).

v2: Use cmpxchg to replace READ_ONCE/WRITE_ONCE for more explicit
control of the ordering wrt to interrupt generation and interrupt
checking in the bottom-half.
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/1467390209-3576-14-git-send-email-chris@chris-wilson.co.uk

If we have multiple waiters, we may find that many complete on the same
wake up. If we first inspect the seqno from the CPU cache, we may reduce
the number of heavyweight coherent seqno reads we require.
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/1467390209-3576-13-git-send-email-chris@chris-wilson.co.uk

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

When waiting for an interrupt (waiting for the engine to complete some
work), we know we are the only waiter to be woken on this engine. We also
know when the GPU has nearly completed our request (or at least started
processing it), so after being woken and we detect that the GPU is
active and working on our request, allow us the bottom-half (the first
waiter who wakes up to handle checking the seqno after the interrupt) to
spin for a very short while to reduce client latencies.

The impact is minimal, there was an improvement to the realtime-vs-many
clients case, but exporting the function proves useful later. However,
it is tempting to adjust irq_seqno_barrier to include the spin. The
problem is first ensuring that the "start-of-request" seqno is coherent
as we use that as our basis for judging when it is ok to spin. If we
could, spinning there could dramatically shorten some sleeps, and allow
us to make the barriers more conservative to handle missed seqno writes
on more platforms (all gen7+ are known to have the occasional issue, at
least).
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/1467390209-3576-7-git-send-email-chris@chris-wilson.co.uk

One particularly stressful scenario consists of many independent tasks
all competing for GPU time and waiting upon the results (e.g. realtime
transcoding of many, many streams). One bottleneck in particular is that
each client waits on its own results, but every client is woken up after
every batchbuffer - hence the thunder of hooves as then every client must
do its heavyweight dance to read a coherent seqno to see if it is the
lucky one.

Ideally, we only want one client to wake up after the interrupt and
check its request for completion. Since the requests must retire in
order, we can select the first client on the oldest request to be woken.
Once that client has completed his wait, we can then wake up the
next client and so on. However, all clients then incur latency as every
process in the chain may be delayed for scheduling - this may also then
cause some priority inversion. To reduce the latency, when a client
is added or removed from the list, we scan the tree for completed
seqno and wake up all the completed waiters in parallel.

Using igt/benchmarks/gem_latency, we can demonstrate this effect. The
benchmark measures the number of GPU cycles between completion of a
batch and the client waking up from a call to wait-ioctl. With many
concurrent waiters, with each on a different request, we observe that
the wakeup latency before the patch scales nearly linearly with the
number of waiters (before external factors kick in making the scaling much
worse). After applying the patch, we can see that only the single waiter
for the request is being woken up, providing a constant wakeup latency
for every operation. However, the situation is not quite as rosy for
many waiters on the same request, though to the best of my knowledge this
is much less likely in practice. Here, we can observe that the
concurrent waiters incur extra latency from being woken up by the
solitary bottom-half, rather than directly by the interrupt. This
appears to be scheduler induced (having discounted adverse effects from
having a rbtree walk/erase in the wakeup path), each additional
wake_up_process() costs approximately 1us on big core. Another effect of
performing the secondary wakeups from the first bottom-half is the
incurred delay this imposes on high priority threads - rather than
immediately returning to userspace and leaving the interrupt handler to
wake the others.

To offset the delay incurred with additional waiters on a request, we
could use a hybrid scheme that did a quick read in the interrupt handler
and dequeued all the completed waiters (incurring the overhead in the
interrupt handler, not the best plan either as we then incur GPU
submission latency) but we would still have to wake up the bottom-half
every time to do the heavyweight slow read. Or we could only kick the
waiters on the seqno with the same priority as the current task (i.e. in
the realtime waiter scenario, only it is woken up immediately by the
interrupt and simply queues the next waiter before returning to userspace,
minimising its delay at the expense of the chain, and also reducing
contention on its scheduler runqueue). This is effective at avoid long
pauses in the interrupt handler and at avoiding the extra latency in
realtime/high-priority waiters.

v2: Convert from a kworker per engine into a dedicated kthread for the
bottom-half.
v3: Rename request members and tweak comments.
v4: Use a per-engine spinlock in the breadcrumbs bottom-half.
v5: Fix race in locklessly checking waiter status and kicking the task on
adding a new waiter.
v6: Fix deciding when to force the timer to hide missing interrupts.
v7: Move the bottom-half from the kthread to the first client process.
v8: Reword a few comments
v9: Break the busy loop when the interrupt is unmasked or has fired.
v10: Comments, unnecessary churn, better debugging from Tvrtko
v11: Wake all completed waiters on removing the current bottom-half to
reduce the latency of waking up a herd of clients all waiting on the
same request.
v12: Rearrange missed-interrupt fault injection so that it works with
igt/drv_missed_irq_hang
v13: Rename intel_breadcrumb and friends to intel_wait in preparation
for signal handling.
v14: RCU commentary, assert_spin_locked
v15: Hide BUG_ON behind the compiler; report on gem_latency findings.
v16: Sort seqno-groups by priority so that first-waiter has the highest
task priority (and so avoid priority inversion).
v17: Add waiters to post-mortem GPU hang state.
v18: Return early for a completed wait after acquiring the spinlock.
Avoids adding ourselves to the tree if the is already complete, and
skips the awkward question of why we don't do completion wakeups for
waits earlier than or equal to ourselves.
v19: Prepare for init_breadcrumbs to fail. Later patches may want to
allocate during init, so be prepared to propagate back the error code.

Testcase: igt/gem_concurrent_blit
Testcase: igt/benchmarks/gem_latency
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: "Rogozhkin, Dmitry V" <dmitry.v.rogozhkin@intel.com>
Cc: "Gong, Zhipeng" <zhipeng.gong@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Dave Gordon <david.s.gordon@intel.com>
Cc: "Goel, Akash" <akash.goel@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> #v18
Link: http://patchwork.freedesktop.org/patch/msgid/1467390209-3576-6-git-send-email-chris@chris-wilson.co.uk

Currently __i915_wait_request uses a per-engine wait_queue_t for the dual
purpose of waking after the GPU advances or for waking after an error.
In the future, we may add even more wake sources and require greater
separation, but for now we can conceptually simplify wakeups by separating
the two sources. In particular, this allows us to use different wait-queues
(e.g. one on the engine advancement, a global one for errors and one on
each requests) without any hassle.
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/1467390209-3576-5-git-send-email-chris@chris-wilson.co.uk

Since the function is a small wrapper around schedule_delayed_work(),
move it inline to remove the function call overhead for the principle
caller.
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/1467390209-3576-4-git-send-email-chris@chris-wilson.co.uk

The queue only ever contains at most one item and has no special flags.
It is just a very simple wrapper around the system-wq - a complication
with no benefits.

v2: Use the system_long_wq as we may wish to capture the error state
after detecting the hang - which may take a bit of time.
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/1467390209-3576-3-git-send-email-chris@chris-wilson.co.uk

Since we have a sequence of register reads and writes, we can reduce the
latency of starting the BSD ring by performing all the mmio operations
under the same forcewake wakeref.
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/1467297225-21379-62-git-send-email-chris@chris-wilson.co.uk

Ville Syrjälä reported that in the majority of wait_for(I915_READ()) he
inspect, most completed within the first couple of reads and that the
delay between those wait_for() reads was the ratelimiting step for many
code paths. For example, __gen6_update_ring_freq() was blamed for
slowing down boot by many milliseconds, but under Ville's scrutiny the
issue was just excessive delay waiting for sandybridge_pcode_write().

We can eliminate the wait by initially using a busyspin upon the register
read and only fallback to the sleeping loop in cases where the hardware
is indeed too slow. A threshold of 2 microseconds is used as the initial
ballpark.

To avoid excessive code bloating from converting every wait_for() into a
hybrid busy/sleep loop, we extend wait_for_register_fw() and export it
for use by other callers.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467297225-21379-1-git-send-email-chris@chris-wilson.co.uk

Since commit 2ed53a94 ("drm/i915: On GPU reset, set the HWS
breadcrumb to the last seqno") once a hang is completed, the seqno is
advanced past all current requests. With this we know that if we wake up
from waiting for a request, if a hang has occurred and reset completed,
our request will be considered complete (i.e.
i915_gem_request_completed() returns true). Therefore we only need to
worry about the situation where a hang has occurred, but not yet reset,
where we may need to release our struct_mutex. Since we don't need to
detect the completed reset using the global gpu_error->reset_counter
anymore, we do not need to track the reset_counter epoch inside the
request.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Arun Siluvery <arun.siluvery@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467211874-11552-1-git-send-email-chris@chris-wilson.co.ukReviewed-by: NArun Siluvery <arun.siluvery@linux.intel.com>

Fix build errors when ACPI is not enabled by adding function stubs:

../drivers/gpu/drm/i915/i915_drv.c: In function 'i915_drm_suspend':
../drivers/gpu/drm/i915/i915_drv.c:635:2: error: implicit declaration of function 'intel_opregion_unregister' [-Werror=implicit-function-declaration]
  intel_opregion_unregister(dev_priv);
../drivers/gpu/drm/i915/i915_drv.c: In function 'i915_drm_resume':
../drivers/gpu/drm/i915/i915_drv.c:798:2: error: implicit declaration of function 'intel_opregion_register' [-Werror=implicit-function-declaration]
  intel_opregion_register(dev_priv);
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: intel-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Fixes: 03d92e47 ("drm/i915/opregion: Rename init/fini functions to register/unregister")
Cc: drm-intel-fixes@lists.freedesktop.org
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
[Jani: dropped the stale init/fini declarations]
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467028399-9965-1-git-send-email-jani.nikula@intel.com

We only need to force a switch to the kernel context placeholder during
eviction. All other uses of i915_gpu_idle() just want to wait until
existing work on the GPU is idle. Rename i915_gpu_idle() to
i915_gem_wait_for_idle() to avoid any implications about "parking" the
context first.

v2: Tweak an error message if the wait fails for the ilk vtd w/a
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466776558-21516-6-git-send-email-chris@chris-wilson.co.uk

This is so that we have symmetry with intel_lrc.c and avoid a source of
if (i915.enable_execlists) layering violation within i915_gem_context.c -
that is we move the specific handling of the dev_priv->kernel_context
for legacy submission into the legacy submission code.

This depends upon the init/fini ordering between contexts and engines
already defined by intel_lrc.c, and also exporting the context alignment
required for pinning the legacy context.

v2: Separate out pin/unpin context funcs for greater symmetry with
intel_lrc. One more step towards unifying behaviour between the two
classes of engines and towards fixing another bug in i915_switch_context
vs requests.
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/1466776558-21516-2-git-send-email-chris@chris-wilson.co.uk

i915_dma.c used to contain the DRI1/UMS horror show, but now all that
remains are the out-of-place driver level interfaces (such as
allocating, initialising and registering the driver). These should be in
i915_drv.c alongside similar routines for suspend/resume.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466773227-7994-10-git-send-email-chris@chris-wilson.co.uk

Baby step, update to_i915() conversion from drm_device to
drm_i915_private:

   text	   data	    bss	    dec	    hex	filename
1108812	  23207	    416	1132435	 114793	i915.ko (before)
1104999	  23207	    416	1128622	 1138ae	i915.ko (after)
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466773227-7994-9-git-send-email-chris@chris-wilson.co.uk

drm_connector_register_all() is now automatically called by
drm_dev_register(), and so we no longer have to do so ourselves (via
intel_modeset_register() after calling drm_dev_register()). Similarly
for unregistering.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1466773227-7994-8-git-send-email-chris@chris-wilson.co.uk

Take control over allocating, loading and registering the driver from the
DRM midlayer by performing it manually from i915_pci_probe. This allows
us to carefully control the order of when we setup the hardware vs when
it becomes visible to third parties (including userspace). The current
ordering makes the driver visible to userspace first (in order to
coordinate with removed DRI1 userspace), but that ordering incurs risk.
The risk increases as we strive for more asynchronous loading.

One side effect of controlling the allocation is that we can allocate
both the drm_device + drm_i915_private in one block, the next step
towards subclassing.

Unload is still left as before, a mix of midlayer and driver.

v2: After drm_dev_init(), we should call drm_dev_unref() so that we call
drm_dev_release() and free everything from drm_dev_init().
v3: Fixup missed error code for failing to allocate dev_priv
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: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1466773227-7994-6-git-send-email-chris@chris-wilson.co.uk

Currently debugfs files are created before the driver is even loads.
This gives the opportunity for userspace to open that interface and poke
around before the backing data structures are initialised - with the
possibility of oopsing or worse.

Move the creation of the debugfs files to our registration phase, where
we announce our presence to the world when we are ready, i.e the
sequence changes from

	drm_dev_register()
	 -> drm_minor_register()
	  -> drm_debugfs_init()
	   -> i915_debugfs_init()
	 -> i915_driver_load()

to

	drm_dev_register()
	 -> drm_minor_register()
	  -> drm_debugfs_init()
	 -> i915_driver_load()
	  -> i915_debugfs_register()
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1466773227-7994-5-git-send-email-chris@chris-wilson.co.uk

Defer connector registration from during construction to the driver
registration phase. This is important for ordering the action correctly,
e.g. not using debugfs before it is ready.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1466773227-7994-4-git-send-email-chris@chris-wilson.co.uk

Currently the backlight is being registered in the load phase (before
the display and its objects are registered). Move the backlight
registration into the analogous phase by performing it from the
connector registration, just after its creation.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1466773227-7994-3-git-send-email-chris@chris-wilson.co.uk

Effectively removes one layer of indirection between the mask of
possible engines and the engine constructors. Instead of spelling
out in code the mapping of HAS_<engine> to constructors, makes
more use of the recently added data driven approach by putting
engine constructor vfuncs into the table as well.

Effect is fewer lines of source and smaller binary.

At the same time simplify the error handling since engine
destructors can run on unitialized engines anyway.

Similar approach could be done for legacy submission is wanted.

v2: Removed ugly BUILD_BUG_ONs in favour of newly introduced
    ENGINE_MASK and HAS_ENGINE macros.
    Also removed the forward declarations by shuffling functions
    around.

v3: Warn when logical_rings table does not contain enough data
    and disable the engines which could not be initialized.
    (Chris Wilson)

v4: Chris Wilson suggested a nicer engine init loop.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1466689961-23232-1-git-send-email-tvrtko.ursulin@linux.intel.com

Also extract drm_auth.h for nicer grouping.

v2: Nuke the other comments since they don't really explain a lot, and
within the drm core we generally only document functions exported to
drivers: The main audience for these docs are driver writers.

v3: Limit the exposure of drm_master internals by only including
drm_auth.h where it is neede (Chris).

v4: Spelling polish (Emil).

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NEmil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

No need for local struct drm_device * since dev_priv is the
correct thing to pass in to NEEDS_WaRsDisableCoarsePowerGating
anyway. Changed the macro definition for the latter to reflect
that as well.

v2: Alignment bikeshed.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Dave Gordon <david.s.gordon@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1466518034-24838-1-git-send-email-tvrtko.ursulin@linux.intel.com

... instead of the previous ORIGIN_GTT. This should actually
invalidate FBC once something is written on the frontbuffer using WC
mmaps. The problem with ORIGIN_GTT is that the automatic hardware
tracking is not able to detect the WC writes as it can detect the GTT
writes.

This should help fix the SKL bug where nothing happens when you type
your username/password on lightdm.

This patch was originally pasted on an email by Chris and converted to
an actual git patch by Paulo.

v2 (from Paulo):
 - Make it a full variable instead of a bit-field (Daniel)
 - Use WRITE_ONCE (Chris)
v3 (from Paulo):
 - Remove huge comment since now we have WRITE_ONCE (Chris)
 - Remove uneeded new line (Chris)
 - Add Chris' Signed-off-by, authorized via IRC

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466185599-26401-1-git-send-email-paulo.r.zanoni@intel.com

Currently to see if an object is backed by struct pages (as opposed to
being a simple pointer to stolen memory, for example) we do a manual
check on the obj->ops->flags. This is quite shouty and before adding
more checks in future, we should make it a bit calmer.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466431552-17860-1-git-send-email-chris@chris-wilson.co.uk

Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We now have a connector->func that serves the same purpose as our own
intel_connector->unregister vfunc allowing us to unwrap ourselves and
use drm_connector_register() (and friends) as the central function.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1466160034-12173-2-git-send-email-chris@chris-wilson.co.uk

GVT workload scheduler needs special host LRC contexts, the so called
"shadow LRC context" to submit guest workload to host i915. During the
guest workload submission, workload scheduler fills the shadow LRC
context with the content of guest LRC context: engine context is copied
without changes, ring context is mostly owned by host i915.

v8:

- Remove the graph temporarily. (Chris)
- Use interruptible mutex_lock. (Chris)
- Rename the function name of creating a GVT context. (Chris)
- Add the missing declaration in i915_drv.h (Chris)

v7:

- Move chart to a better place. (Joonas)

v6:

- Make GVT code as dead code when !CONFIG_DRM_I915_GVT. (Chris)

v5:
- Only compile this feature when CONFIG_DRM_I915_GVT is enabled. (Tvrtko)
- Rebase the code into new repo.
- Add a comment about the ring buffer size. (Joonas)

v2:

Mostly based on Daniel's idea. Call the refactored core logic of GEM
context creation service and LRC context creation service to create the GVT
context.
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Signed-off-by: NZhi Wang <zhi.a.wang@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1466078825-6662-10-git-send-email-zhi.a.wang@intel.com

This patch introduces the support of LRC context single submission.
As GVT context may come from different guests, which require different
configuration of render registers. It can't be combined into a dual ELSP
submission combo.

Only GVT-g will create this kinds of GEM context currently.

v8:

- Rename the data member in struct i915_gem_context. (Chris)

v7:

- Fix typos in commit message. (Joonas)

v6:
- Make GVT code as dead code when !CONFIG_DRM_I915_GVT. (Chris)

v5:

- Only compile this feature when CONFIG_DRM_I915_GVT=y. (Tvrtko)
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Signed-off-by: NZhi Wang <zhi.a.wang@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1466078825-6662-9-git-send-email-zhi.a.wang@intel.com

This patch introduces an approach to track the execlist context status
change.

GVT-g uses GVT context as the "shadow context". The content inside GVT
context will be copied back to guest after the context is idle. And GVT-g
has to know the status of the execlist context.

This function is configurable when creating a new GEM context. Currently,
Only GVT-g will create the "status-change-notification" enabled GEM
context.

v10:

- Fix the identation. (Joonas)

v8:

- Remove the boolean flag in struct i915_gem_context. (Joonas)

v7:

- Remove per-engine ctx status notifiers. Use one status notifier for all
engines. (Joonas)
- Add prefix "INTEL_" for related definitions. (Joonas)
- Refine the comments in execlists_context_status_change(). (Joonas)

v6:

- When !CONFIG_DRM_I915_GVT, make GVT code as dead code then compiler
could automatically eliminate them for us. (Chris)
- Always initialize the notifier header, so it could be switched on/off
at runtime. (Chris)

v5:

- Only compile this feature when CONFIG_DRM_I915_GVT is enabled.(Tvrtko)

Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> (v8)
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Signed-off-by: NZhi Wang <zhi.a.wang@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466078825-6662-8-git-send-email-zhi.a.wang@intel.comSigned-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Currently the addressing mode bit in context descriptor is statically
generated from the configuration of system-wide PPGTT usage model.

GVT-g will load the PPGTT shadow page table by itself and probably one
guest is using a different addressing mode with i915 host. The addressing
mode bits of a LRC context should be configurable under this case.

v10:

- Fix the identation. (Joonas)

v9:
- Rename the data member in struct i915_gem_context. (Chris)

v8:
- Rename the data member in struct i915_gem_context. (Chris)

v7:
- Move context addressing mode bit into i915_reg.h. (Joonas/Chris)
- Add prefix "INTEL_" for related definitions. (Joonas)

v6:
- Directly save the addressing mode bits inside i915_gem_context. (Chris)
- Move the LRC context addressing mode bits into intel_lrc.h. (Chris)

v5:
- Change USES_FULL_48BIT(dev) to USES_FULL_48BIT(dev_priv) (Tvrtko)

Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> (v9)
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Signed-off-by: NZhi Wang <zhi.a.wang@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1466078825-6662-7-git-send-email-zhi.a.wang@intel.com

This patch introduces an option for configuring the ring buffer size
of a LRC context after the context creation.

v9:
- Fix an identation issue. (Chris)

v8:
- Rename the data member in i915_gem_context. (Chris)
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NZhi Wang <zhi.a.wang@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1466078825-6662-6-git-send-email-zhi.a.wang@intel.com

This patch introduces the very basic framework of GVT-g device model,
includes basic prototypes, definitions, initialization.

v12:
- Call intel_gvt_init() in driver early initialization stage. (Chris)

v8:
- Remove the GVT idr and mutex in intel_gvt_host. (Joonas)

v7:
- Refine the URL link in Kconfig. (Joonas)
- Refine the introduction of GVT-g host support in Kconfig. (Joonas)
- Remove the macro GVT_ALIGN(), use round_down() instead. (Joonas)
- Make "struct intel_gvt" a data member in struct drm_i915_private.(Joonas)
	- Remove {alloc, free}_gvt_device()
	- Rename intel_gvt_{create, destroy}_gvt_device()
	- Expost intel_gvt_init_host()
- Remove the dummy "struct intel_gvt" declaration in intel_gvt.h (Joonas)

v6:
- Refine introduction in Kconfig. (Chris)
- The exposed API functions will take struct intel_gvt * instead of
void *. (Chris/Tvrtko)
- Remove most memebers of strct intel_gvt_device_info. Will add them
in the device model patches.(Chris)
- Remove gvt_info() and gvt_err() in debug.h. (Chris)
- Move GVT kernel parameter into i915_params. (Chris)
- Remove include/drm/i915_gvt.h, as GVT-g will be built within i915.
- Remove the redundant struct i915_gvt *, as the functions in i915
will directly take struct intel_gvt *.
- Add more comments for reviewer.

v5:
Take Tvrtko's comments:
- Fix the misspelled words in Kconfig
- Let functions take drm_i915_private * instead of struct drm_device *
- Remove redundant prints/local varible initialization

v3:
Take Joonas' comments:
- Change file name i915_gvt.* to intel_gvt.*
- Move GVT kernel parameter into intel_gvt.c
- Remove redundant debug macros
- Change error handling style
- Add introductions for some stub functions
- Introduce drm/i915_gvt.h.

Take Kevin's comments:
- Move GVT-g host/guest check into intel_vgt_balloon in i915_gem_gtt.c

v2:
- Introduce i915_gvt.c.
It's necessary to introduce the stubs between i915 driver and GVT-g host,
as GVT-g components is configurable in kernel config. When disabled, the
stubs here do nothing.

Take Joonas' comments:
- Replace boolean return value with int.
- Replace customized info/warn/debug macros with DRM macros.
- Document all non-static functions like i915.
- Remove empty and unused functions.
- Replace magic number with marcos.
- Set GVT-g in kernel config to "n" by default.
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: NZhi Wang <zhi.a.wang@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466078825-6662-5-git-send-email-zhi.a.wang@intel.comSigned-off-by: NChris Wilson <chris@chris-wilson.co.uk>

This mode allows to assign EUs to pools which can process work collectively.
The command to enable this mode should be issued as part of context initialization.

The pooled mode is global, once enabled it has to stay the same across all
contexts until HW reset hence this is sent in auxiliary golden context batch.
Thanks to Mika for the preliminary review and comments.

v2: explain why this is enabled in golden context, use feature flag while
enabling the support (Chris)

v3: Include only kernel support as userspace support is not available yet.

User space clients need to know when the pooled EU feature is present
and enabled on the hardware so that they can adapt work submissions.
Create a new device info flag for this purpose.

Set has_pooled_eu to true in the Broxton static device info - Broxton
supports the feature in hardware and the driver will enable it by
default.

We need to add getparam ioctls to enable userspace to query availability of
this feature and to retrieve min. no of eus in a pool but we will expose
them once userspace support is available. Opensource users for this feature
are mesa, libva and beignet.

Beignet team is currently working on adding userspace support.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v2)
Cc: Winiarski, Michal <michal.winiarski@intel.com>
Cc: Zou, Nanhai <nanhai.zou@intel.com>
Cc: Yang, Rong R <rong.r.yang@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Armin Reese <armin.c.reese@intel.com>
Cc: Tim Gore <tim.gore@intel.com>
Signed-off-by: NJeff McGee <jeff.mcgee@intel.com>
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NMichał Winiarski <michal.winiarski@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>