An old optimisation to reduce the number of atomics per batch sadly
relies on struct_mutex for coordination. In order to remove struct_mutex
from serialising object/context closing, always taking and releasing an
active reference on first use / last use greatly simplifies the locking.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528092956.14910-15-chris@chris-wilson.co.uk

Continuing the theme of separating out the GEM clutter.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528092956.14910-8-chris@chris-wilson.co.uk

Some users require that when a master batch is executed on one particular
engine, a companion batch is run simultaneously on a specific slave
engine. For this purpose, we introduce virtual engine bonding, allowing
maps of master:slaves to be constructed to constrain which physical
engines a virtual engine may select given a fence on a master engine.

For the moment, we continue to ignore the issue of preemption deferring
the master request for later. Ideally, we would like to then also remove
the slave and run something else rather than have it stall the pipeline.
With load balancing, we should be able to move workload around it, but
there is a similar stall on the master pipeline while it may wait for
the slave to be executed. At the cost of more latency for the bonded
request, it may be interesting to launch both on their engines in
lockstep. (Bubbles abound.)

Opens: Also what about bonding an engine as its own master? It doesn't
break anything internally, so allow the silliness.

v2: Emancipate the bonds
v3: Couple in delayed scheduling for the selftests
v4: Handle invalid mutually exclusive bonding
v5: Mention what the uapi does
v6: s/nbond/num_bonds/
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: https://patchwork.freedesktop.org/patch/msgid/20190521211134.16117-9-chris@chris-wilson.co.uk

Having allowed the user to define a set of engines that they will want
to only use, we go one step further and allow them to bind those engines
into a single virtual instance. Submitting a batch to the virtual engine
will then forward it to any one of the set in a manner as best to
distribute load.  The virtual engine has a single timeline across all
engines (it operates as a single queue), so it is not able to concurrently
run batches across multiple engines by itself; that is left up to the user
to submit multiple concurrent batches to multiple queues. Multiple users
will be load balanced across the system.

The mechanism used for load balancing in this patch is a late greedy
balancer. When a request is ready for execution, it is added to each
engine's queue, and when an engine is ready for its next request it
claims it from the virtual engine. The first engine to do so, wins, i.e.
the request is executed at the earliest opportunity (idle moment) in the
system.

As not all HW is created equal, the user is still able to skip the
virtual engine and execute the batch on a specific engine, all within the
same queue. It will then be executed in order on the correct engine,
with execution on other virtual engines being moved away due to the load
detection.

A couple of areas for potential improvement left!

- The virtual engine always take priority over equal-priority tasks.
Mostly broken up by applying FQ_CODEL rules for prioritising new clients,
and hopefully the virtual and real engines are not then congested (i.e.
all work is via virtual engines, or all work is to the real engine).

- We require the breadcrumb irq around every virtual engine request. For
normal engines, we eliminate the need for the slow round trip via
interrupt by using the submit fence and queueing in order. For virtual
engines, we have to allow any job to transfer to a new ring, and cannot
coalesce the submissions, so require the completion fence instead,
forcing the persistent use of interrupts.

- We only drip feed single requests through each virtual engine and onto
the physical engines, even if there was enough work to fill all ELSP,
leaving small stalls with an idle CS event at the end of every request.
Could we be greedy and fill both slots? Being lazy is virtuous for load
distribution on less-than-full workloads though.

Other areas of improvement are more general, such as reducing lock
contention, reducing dispatch overhead, looking at direct submission
rather than bouncing around tasklets etc.

sseu: Lift the restriction to allow sseu to be reconfigured on virtual
engines composed of RENDER_CLASS (rcs).

v2: macroize check_user_mbz()
v3: Cancel virtual engines on wedging
v4: Commence commenting
v5: Replace 64b sibling_mask with a list of class:instance
v6: Drop the one-element array in the uabi
v7: Assert it is an virtual engine in to_virtual_engine()
v8: Skip over holes in [class][inst] so we can selftest with (vcs0, vcs2)

Link: https://github.com/intel/media-driver/pull/283Signed-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: https://patchwork.freedesktop.org/patch/msgid/20190521211134.16117-6-chris@chris-wilson.co.uk

A usecase arose out of handling context recovery in mesa, whereby they
wish to recreate a context with fresh logical state but preserving all
other details of the original. Currently, they create a new context and
iterate over which bits they want to copy across, but it would much more
convenient if they were able to just pass in a target context to clone
during creation. This essentially extends the setparam during creation
to pull the details from a target context instead of the user supplied
parameters.

The ideal here is that we don't expose control over anything more than
can be obtained via CONTEXT_PARAM. That is userspace retains explicit
control over all features, and this api is just convenience.

For example, you could replace

	struct context_param p = { .param = CONTEXT_PARAM_VM };

	param.ctx_id = old_id;
	gem_context_get_param(&p.param);

	new_id = gem_context_create();

	param.ctx_id = new_id;
	gem_context_set_param(&p.param);

	gem_vm_destroy(param.value); /* drop the ref to VM_ID handle */

with

	struct create_ext_param p = {
	  { .name = CONTEXT_CREATE_CLONE },
	  .clone_id = old_id,
	  .flags = CLONE_FLAGS_VM
	}
	new_id = gem_context_create_ext(&p);

and not have to worry about stray namespace pollution etc.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190521211134.16117-5-chris@chris-wilson.co.uk

The SINGLE_TIMELINE flag can be used to create a context such that all
engine instances within that context share a common timeline. This can
be useful for mixing operations between real and virtual engines, or
when using a composite context for a single client API context.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190521211134.16117-4-chris@chris-wilson.co.uk

Allow the user to specify a local engine index (as opposed to
class:index) that they can use to refer to a preset engine inside the
ctx->engine[] array defined by an earlier I915_CONTEXT_PARAM_ENGINES.
This will be useful for setting SSEU parameters on virtual engines that
are local to the context and do not have a valid global class:instance
lookup.

Note that due to the ambiguity in using class:instance with
ctx->engines[], if a user supplied engine map is active the user must
specify the engine to alter by its index into the ctx->engines[].
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: https://patchwork.freedesktop.org/patch/msgid/20190521211134.16117-3-chris@chris-wilson.co.uk

Over the last few years, we have debated how to extend the user API to
support an increase in the number of engines, that may be sparse and
even be heterogeneous within a class (not all video decoders created
equal). We settled on using (class, instance) tuples to identify a
specific engine, with an API for the user to construct a map of engines
to capabilities. Into this picture, we then add a challenge of virtual
engines; one user engine that maps behind the scenes to any number of
physical engines. To keep it general, we want the user to have full
control over that mapping. To that end, we allow the user to constrain a
context to define the set of engines that it can access, order fully
controlled by the user via (class, instance). With such precise control
in context setup, we can continue to use the existing execbuf uABI of
specifying a single index; only now it doesn't automagically map onto
the engines, it uses the user defined engine map from the context.

v2: Fixup freeing of local on success of get_engines()
v3: Allow empty engines[]
v4: s/nengine/num_engines/
v5: Replace 64 limit on num_engines with a note that execbuf is
currently limited to only using the first 64 engines.
v6: Actually use the engines_mutex to guard the ctx->engines.

Testcase: igt/gem_ctx_engines
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: https://patchwork.freedesktop.org/patch/msgid/20190521211134.16117-2-chris@chris-wilson.co.uk

Having hid the partially exposed new ABI from the PR, put it back again
for completion of context recovery. A significant part of context
recovery is the ability to reuse as much of the old context as is
feasible (to avoid expensive reconstruction). The biggest chunk kept
hidden at the moment is fine-control over the ctx->ppgtt (the GPU page
tables and associated translation tables and kernel maps), so make
control over the ctx->ppgtt explicit.

This allows userspace to create and share virtual memory address spaces
(within the limits of a single fd) between contexts they own, along with
the ability to query the contexts for the vm state.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190521211134.16117-1-chris@chris-wilson.co.uk

If the context has not been used yet, it needs no barrier, and in the
process fix up the selftest in mock_contexts.

Testcase: igt/gem_ctx_clone/vm
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: https://patchwork.freedesktop.org/patch/msgid/20190429090735.326-1-chris@chris-wilson.co.uk

We no longer need to track the active intel_contexts within each engine,
allowing us to drop a tricky mutex_lock from inside unpin (which may
occur inside fs_reclaim).
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190426163336.15906-8-chris@chris-wilson.co.uk

We switched to a tree of per-engine HW context to accommodate the
introduction of virtual engines. However, we plan to also support
multiple instances of the same engine within the GEM context, defeating
our use of the engine as a key to looking up the HW context. Just
allocate a logical per-engine instance and always use an index into the
ctx->engines[]. Later on, this ctx->engines[] may be replaced by a user
specified map.

v2: Add for_each_gem_engine() helper to iterator within the engines lock
v3: intel_context_create_request() helper
v4: s/unsigned long/unsigned int/ 4 billion engines is quite enough.
v5: Push iterator locking to caller
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: https://patchwork.freedesktop.org/patch/msgid/20190426163336.15906-7-chris@chris-wilson.co.uk

Move the intel_context_instance() to the caller so that we can decouple
ourselves from one context instance per engine.

v2: Rename pin_lock() to lock_pinned(), hopefully that is clearer.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190426163336.15906-5-chris@chris-wilson.co.uk

It was noted that we made the same mistake for VM_ID as for object
handles, whereby we ensured that we only allocated a single handle for
one ppgtt. This has the unfortunate consequence for userspace that they
need to reference count the handles to avoid destroying an active ID. If
we allow multiple handles to the same ppgtt, userspace can freely
unreference any handle they own without fear of destroying the same
handle in use elsewhere.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190425054333.27299-1-chris@chris-wilson.co.uk

In the current scheme, on submitting a request we take a single global
GEM wakeref, which trickles down to wake up all GT power domains. This
is undesirable as we would like to be able to localise our power
management to the available power domains and to remove the global GEM
operations from the heart of the driver. (The intent there is to push
global GEM decisions to the boundary as used by the GEM user interface.)

Now during request construction, each request is responsible via its
logical context to acquire a wakeref on each power domain it intends to
utilize. Currently, each request takes a wakeref on the engine(s) and
the engines themselves take a chipset wakeref. This gives us a
transition on each engine which we can extend if we want to insert more
powermangement control (such as soft rc6). The global GEM operations
that currently require a struct_mutex are reduced to listening to pm
events from the chipset GT wakeref. As we reduce the struct_mutex
requirement, these listeners should evaporate.

Perhaps the biggest immediate change is that this removes the
struct_mutex requirement around GT power management, allowing us greater
flexibility in request construction. Another important knock-on effect,
is that by tracking engine usage, we can insert a switch back to the
kernel context on that engine immediately, avoiding any extra delay or
inserting global synchronisation barriers. This makes tracking when an
engine and its associated contexts are idle much easier -- important for
when we forgo our assumed execution ordering and need idle barriers to
unpin used contexts. In the process, it means we remove a large chunk of
code whose only purpose was to switch back to the kernel context.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190424200717.1686-5-chris@chris-wilson.co.uk

Start acquiring the logical intel_context and using that as our primary
means for request allocation. This is the initial step to allow us to
avoid requiring struct_mutex for request allocation along the
perma-pinned kernel context, but it also provides a foundation for
breaking up the complex request allocation to handle different scenarios
inside execbuf.

For the purpose of emitting a request from inside retirement (see the
next patch for engine power management), we also need to lift control
over the timeline mutex to the caller.

v2: Note that the request carries the active reference upon construction.
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: https://patchwork.freedesktop.org/patch/msgid/20190424200717.1686-4-chris@chris-wilson.co.uk

Start partitioning off the code that talks to the hardware (GT) from the
uapi layers and move the device facing code under gt/

One casualty is s/intel_ringbuffer.h/intel_engine.h/ with the plan to
subdivide that header and body further (and split out the submission
code from the ringbuffer and logical context handling). This patch aims
to be simple motion so git can fixup inflight patches with little mess.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Acked-by: NJani Nikula <jani.nikula@intel.com>
Acked-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190424174839.7141-1-chris@chris-wilson.co.uk

As we push for better compartmentalisation, it is more convenient to
copy the default sseu configuration from the engine into the derived
logical context, than it is to dig it out from i915->runtime_info.

v2: Use intel_sseu_from_device_info() to describe the converter
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: https://patchwork.freedesktop.org/patch/msgid/20190424095134.30249-1-chris@chris-wilson.co.uk

SSEU reprogramming of the context introduced the notion of engine class
and instance for a forwards compatible method of describing any engine
beyond the old execbuf interface. We wish to adopt this class:instance
description for more interfaces, so pull it out into a separate type for
userspace convenience.

Fixes: e46c2e99 ("drm/i915: Expose RPCS (SSEU) configuration to userspace (Gen11 only)")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dmitry Rogozhkin <dmitry.v.rogozhkin@intel.com>
Cc: Tony Ye <tony.ye@intel.com>
Cc: Andi Shyti <andi@etezian.org>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Acked-by: NTony Ye <tony.ye@intel.com>
Reviewed-by: NAndi Shyti <andi@etezian.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190412071416.30097-1-chris@chris-wilson.co.uk

The timeline is strictly ordered, so by inserting the timeline->barrier
request into the timeline->last_request it naturally provides the same
barrier. Consolidate the pair of barriers into one as they serve the
same purpose.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190408091728.20207-4-chris@chris-wilson.co.uk

The PDP registers are an oddity inside the set of context saved
registers in that they take the engine as a parameter to the macro and
not the mmio_base as the others do. Make it accept the engine->mmio_base
for consistency in programming the context registers.

add/remove: 0/0 grow/shrink: 2/1 up/down: 3/-32 (-29)
Function                                     old     new   delta
emit_ppgtt_update                            324     326      +2
capture                                     5102    5103      +1
execlists_init_reg_state.isra               1128    1096     -32

And similar savings later!
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190405123831.9724-1-chris@chris-wilson.co.uk

When we introduced preemption, we chose to keep it disabled for gen8 as
supporting preemption inside GPGPU user batches required various w/a in
userspace. Since then, the desire to preempt long queues of requests
between batches (e.g. within busywaiting semaphores) has grown. So allow
arbitration within the busywaits and between requests, but disable
arbitration within user batches so that we can preempt between requests
and not risk breaking GPGPU.

However, since this preemption is much coarser and doesn't interfere
with userspace, we decline to include it amongst the scheduler
capabilities. (This is also required for us to skip over the preemption
selftests that expect to be able to preempt user batches.)

Michal suggested that we could perhaps allow preemption inside gen8
userspace batches if we can satisfy ourselves that the default
preemption settings are viable with existing userspace (principally
OpenCL which already should carry any known workaround). We could then
merge the two code paths back into one, even dropping the artifical
has-preemption device feature flag.

Testcase: igt/gem_exec_scheduler/semaphore-user
References: beecec90 ("drm/i915/execlists: Preemption!")
Fixes: e8861964 ("drm/i915: Use HW semaphores for inter-engine synchronisation on gen8+")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Michal Winiarski <michal.winiarski@intel.com> #irc
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190329134024.5254-1-chris@chris-wilson.co.uk

We want to use intel_engine_mask_t inside i915_request.h, which means
extracting it from the general header file mess and placing it inside a
types.h. A knock on effect is that the compiler wants to warn about
type-contraction of ALL_ENGINES into intel_engine_maskt_t, so prepare
for the worst.

v2: Use intel_engine_mask_t consistently
v3: Move I915_NUM_ENGINES to its natural home at the end of the enum
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190401162641.10963-1-chris@chris-wilson.co.ukReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

As we only set ctx->file_priv on registering the GEM context after
construction, it is invalid to try and use it in the middle for setting
various parameters. Indeed, we put the file_priv into struct create_ext
so that we have the right file_private available without having to look
at ctx->file_priv. However, it helps to use it!
Reported-by: NJordan Justen <jordan.l.justen@intel.com>
Fixes: b9171541 ("drm/i915: Extend CONTEXT_CREATE to set parameters upon construction")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: NJordan Justen <jordan.l.justen@intel.com>
Tested-by: NJordan Justen <jordan.l.justen@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190330100349.30642-1-chris@chris-wilson.co.uk

The intent was to expose these as part of the means to perform full
context recovery (though not the SINGLE_TIMELINE, that is for later and
just sucked as collateral damage). As that requires a couple more
patches to complete the series, roll back the earlier chunks of ABI for
an intervening PR. We keep all the internals intact and under selftests.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190327105814.14694-1-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

Fixup the errno as we adjusted the error path to receive the errno and
not compute it itself from ERR_PTR(ctx) anymore.

drivers/gpu/drm/i915/i915_gem_context.c:793 i915_gem_context_open() warn: passing a valid pointer to 'PTR_ERR'
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Fixes: 3aa9945a ("drm/i915: Separate GEM context construction and registration to userspace")
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: https://patchwork.freedesktop.org/patch/msgid/20190325090413.19906-2-chris@chris-wilson.co.uk

Initially found issue with closed context debug check when pin
hw_id for GVT context, looks we should always pin hw_id for that
as GVT context is fixed for each vGPU life cycle, and we'd also
like to get pinned hw_id e.g for perf reason, etc.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190311023747.1426-1-zhenyuw@linux.intel.com

Previously, our view has been always to run the engines independently
within a context. (Multiple engines happened before we had contexts and
timelines, so they always operated independently and that behaviour
persisted into contexts.) However, at the user level the context often
represents a single timeline (e.g. GL contexts) and userspace must
ensure that the individual engines are serialised to present that
ordering to the client (or forgot about this detail entirely and hope no
one notices - a fair ploy if the client can only directly control one
engine themselves ;)

In the next patch, we will want to construct a set of engines that
operate as one, that have a single timeline interwoven between them, to
present a single virtual engine to the user. (They submit to the virtual
engine, then we decide which engine to execute on based.)

To that end, we want to be able to create contexts which have a single
timeline (fence context) shared between all engines, rather than multiple
timelines.

v2: Move the specialised timeline ordering to its own function.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190322092325.5883-4-chris@chris-wilson.co.uk

It can be useful to have a single ioctl to create a context with all
the initial parameters instead of a series of create + setparam + setparam
ioctls. This extension to create context allows any of the parameters
to be passed in as a linked list to be applied to the newly constructed
context.

v2: Make a local copy of user setparam (Tvrtko)
v3: Use flags to detect availability of extension interface
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190322092325.5883-3-chris@chris-wilson.co.uk

In preparation to making the ppGTT binding for a context explicit (to
facilitate reusing the same ppGTT between different contexts), allow the
user to create and destroy named ppGTT.

v2: Replace global barrier for swapping over the ppgtt and tlbs with a
local context barrier (Tvrtko)
v3: serialise with struct_mutex; it's lazy but required dammit
v4: Rewrite igt_ctx_shared_exec to be more different (aimed to be more
similarly, turned out different!)

v5: Fix up test unwind for aliasing-ppgtt (snb)
v6: Tighten language for uapi struct drm_i915_gem_vm_control.
v7: Patch the context image for runtime ppgtt switching!

Testcase: igt/gem_vm_create
Testcase: igt/gem_ctx_param/vm
Testcase: igt/gem_ctx_clone/vm
Testcase: igt/gem_ctx_shared
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: https://patchwork.freedesktop.org/patch/msgid/20190322092325.5883-2-chris@chris-wilson.co.uk

The timeline->name is only used for convenience in pretty printing the
i915_request.fence->ops->get_timeline_name() and it is just as
convenient to pull it from the gem_context directly. The few instances
of its use inside GEM_TRACE() has proven more of a nuisance than
helpful, so not worth saving imo.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190321140711.11190-4-chris@chris-wilson.co.uk

The user_handle need only be known by userspace for it to lookup the
context via the idr; internally we have no use for it.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190321140711.11190-3-chris@chris-wilson.co.uk

Define a mutex for the exclusive use of interacting with the per-file
context-idr, that was previously guarded by struct_mutex. This allows us
to reduce the coverage of struct_mutex, with a view to removing the last
bits coordinating GEM context later. (In the short term, we avoid taking
struct_mutex while using the extended constructor functions, preventing
some nasty recursion.)

v2: s/context_lock/context_idr_lock/
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: https://patchwork.freedesktop.org/patch/msgid/20190321140711.11190-2-chris@chris-wilson.co.uk

In later patches, it became apparent that userspace can see a partially
constructed GEM context and begin using it before it was ready, to much
hilarity. Close this window of opportunity by lifting the registration of
the context with userspace (the insertion of the context into the filp's
idr) to the very end of the CONTEXT_CREATE ioctl.
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: https://patchwork.freedesktop.org/patch/msgid/20190321140711.11190-1-chris@chris-wilson.co.uk

For virtual engines, we need to keep the HW context alive while it
remains in use. For regular HW contexts, they are created and kept alive
until the end of the GEM context. For simplicity, generalise the
requirements and keep an active reference to each HW context.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190318212347.30146-2-chris@chris-wilson.co.uk

Large ppGTT are differentiated by the requirement to go to four levels
to address more than 32b. Given the introduction of more 4 level ppGTT
with different sizes of addressable bits, rename i915_vm_is_48b() to
better reflect the commonality of using 4 levels.

Based on a patch by Bob Paauwe.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Bob Paauwe <bob.j.paauwe@intel.com>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190314223839.28258-4-chris@chris-wilson.co.uk

In the next patch, we will want to update live state within a context.
As this state may be in use by the GPU and we haven't been explicitly
tracking its activity, we instead attach it to a request we send down
the context setup with its new state and on retiring that request
cleanup the old state as we then know that it is no longer live.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190309160250.29324-1-chris@chris-wilson.co.uk

Introduce a mutex to start locking the HW contexts independently of
struct_mutex, with a view to reducing the coarse struct_mutex. The
intel_context.pin_mutex is used to guard the transition to and from being
pinned on the gpu, and so is required before starting to build any
request. The intel_context will then remain pinned until the request
completes, but the mutex can be released immediately unpin completion of
pinning the context.

A slight variant of the above is used by per-context sseu that wants to
inspect the pinned status of the context, and requires that it remains
stable (either !pinned or pinned) across its operation. By using the
pin_mutex to serialise operations while pin_count==0, we can take that
pin_mutex for stabilise the boolean pin status.

v2: for Tvrtko!
* Improved commit message.
* Dropped _gpu suffix from gen8_modify_rpcs_gpu.
v3: Repair the locking for sseu selftests
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: https://patchwork.freedesktop.org/patch/msgid/20190308132522.21573-7-chris@chris-wilson.co.uk

In preparation for an ever growing number of engines and so ever
increasing static array of HW contexts within the GEM context, move the
array over to an rbtree, allocated upon first use.

Unfortunately, this imposes an rbtree lookup at a few frequent callsites,
but we should be able to mitigate those by moving over to using the HW
context as our primary type and so only incur the lookup on the boundary
with the user GEM context and engines.

v2: Check for no HW context in guc_stage_desc_init
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: https://patchwork.freedesktop.org/patch/msgid/20190308132522.21573-4-chris@chris-wilson.co.uk

If we place a pointer to the engine specific intel_context_ops in the
engine itself, we can assign the ops pointer on initialising the
context, and then rely on it being set. This simplifies the code in
later patches.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190308132522.21573-3-chris@chris-wilson.co.uk