Kill the blt/render tracking we currently have and use the frontbuffer
tracking infrastructure.

Don't enable things by default yet.

v2: (Rodrigo) Fix small conflict on rebase and typo at subject.
v3: (Paulo) Rebase on RENDER_CS change.
v4: (Paulo) Rebase.
v5: (Paulo) Simplify: flushes don't have origin (Daniel).
            Also rebase due to patch order changes.
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There is a flags word that is passed through the execbuffer code path all the
way from initial decoding of the user parameters down to the very final dispatch
buffer call. It is simply called 'flags'. Unfortuantely, there are many other
flags words floating around in the same blocks of code. Even more once the GPU
scheduler arrives.

This patch makes it more obvious exactly which flags word is which by renaming
'flags' to 'dispatch_flags'. Note that the bit definitions for this flags word
already have an 'I915_DISPATCH_' prefix on them and so are not quite so
ambiguous.

OTC-Jira: VIZ-1587
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
[danvet: Resolve conflict with Chris' rework of the bb parsing.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

As of Gen6, the general purpose area of the hardware status page has shrunk and
now begins at dword 0x30.  i915 driver uses dword 0x20 to store the seqno which
is now reserved.  So shift our HWSP dwords up into the general purpose range
before this bites us.

Note that all available documentation just says this is reserved
without going into details about what it's used for.
Signed-off-by: NThomas Daniel <thomas.daniel@intel.com>
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
[danvet: Add clarification from Thomas that unfortunately Bspec is
silent on what "reserverd" precisely means.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This function is only used in intel_ringbuffer.c, so restrict it to that
file. The function was moved around to avoid a forward declaration and
group it with its user.
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
[danvet: Squash in fixup from Wu Fengguang.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The first pass implementation of execlists required a backpointer to the context to be held
in the intel_ringbuffer. However the context pointer is available higher in the call stack.
Remove the backpointer from the ring buffer structure and instead pass it down through the
call stack.

v2: Integrate this changeset with the removal of duplicate request/execlist queue item members.
v3: Rebase
v4: Rebase. Remove passing of context when the request is passed.
Signed-off-by: NNick Hoath <nicholas.hoath@intel.com>
Reviewed-by: NThomas Daniel <thomas.daniel@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Where there were duplicate variables for the tail, context and ring (engine)
in the gem request and the execlist queue item, use the one from the request
and remove the duplicate from the execlist queue item.

Issue: VIZ-4274

v1: Rebase
v2: Fixed build issues. Keep separate postfix & tail pointers as these are
used in different ways. Reinserted missing full tail pointer update.
Signed-off-by: NNick Hoath <nicholas.hoath@intel.com>
Reviewed-by: NThomas Daniel <thomas.daniel@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is (mostly, some exceptions that need fixing) the hw setup
function which starts the ring. And not the function which allocates
all the resources.

Make this clear by giving it a better name.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Reviewed-by: NDave Gordon <david.s.gordon@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There are numerous places in the code where the driver's idea of
how much space is left in a ring is updated using the driver's
latest notions of the positions of 'head' and 'tail' for the ring.
Among them are some that update one or both of these values before
(re)doing the calculation. In particular, there are four different
places in the code where 'last_retired_head' is copied to 'head'
and then set to -1; and two of these do not have a guard to check
that it has actually been updated since last time it was consumed,
leaving the possibility that the dummy -1 can be transferred from
'last_retired_head' to 'head', causing the space calculation to
produce 'impossible' results (previously seen on Android/VLV).

This code therefore consolidates all the calculation and updating of
these values, such that there is only one place where the ring space
is updated, and it ALWAYS uses (and consumes) 'last_retired_head' if
(and ONLY if) it has been updated since the last call.
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Updated the trace_irq code to use requests instead of seqnos. This includes
reference counting the request object to ensure it sticks around when required.
Note that getting access to the reference counting functions means moving the
inline i915_trace_irq_get() function from intel_ringbuffer.h to i915_drv.h.

For: VIZ-4377
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NThomas Daniel <Thomas.Daniel@intel.com>
[danvet: Resolve conflict due to shuffled merge order.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The OLS value is now obsolete. Exactly the same value is guarateed to be always
available as PLR->seqno. Thus it is safe to remove the OLS completely. And also
to rename the PLR to OLR to keep the 'outstanding lazy ...' naming convention
valid.

For: VIZ-4377
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NThomas Daniel <Thomas.Daniel@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The object structure contains the last read, write and fenced seqno values for
use in syncrhonisation operations. These have now been replaced with their
request structure counterparts.

Note that to ensure that objects do not end up with dangling pointers, the
assignments of last_*_req include reference count updates. Thus a request cannot
be freed if an object is still hanging on to it for any reason.

v2: Corrected 'last_rendering_' to 'last_read_' in a number of comments that did
not get updated when 'last_rendering_seqno' became 'last_read|write_seqno'
several millenia ago.

For: VIZ-4377
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NThomas Daniel <Thomas.Daniel@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Added helper functions for retrieving the ring and seqno entries from a request
structure. This allows the internal workings of the request structure to be
hidden from code that is using these. It also allows for useful
workarounds/debug code to be added as or when necessary.

Note that it is intended that the majority (if not all) uses of the seqno
accessor will disappear eventually as code is updated to use the request
structure itself rather than working with seqno values.

For: VIZ-4377
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NThomas Daniel <Thomas.Daniel@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

With the deprecation of UMS, and by association DRI1, we have a tough
choice when updating the ring access routines. We either rewrite the
DRI1 routines blindly without testing (so likely to be broken) or take
the liberty of declaring them no longer supported and remove them
entirely. This takes the latter approach.

v2: Also remove the DRI1 sarea updates
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Fix rebase conflicts.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Same as with the context, pinning to GGTT regardless is harmful (it
badly fragments the GGTT and can even exhaust it).

Unfortunately, this case is also more complex than the previous one
because we need to map and access the ringbuffer in several places
along the execbuffer path (and we cannot make do by leaving the
default ringbuffer pinned, as before). Also, the context object
itself contains a pointer to the ringbuffer address that we have to
keep updated if we are going to allow the ringbuffer to move around.

v2: Same as with the context pinning, we cannot really do it during
an interrupt. Also, pin the default ringbuffers objects regardless
(makes error capture a lot easier).

v3: Rebased. Take a pin reference of the ringbuffer for each item
in the execlist request queue because the hardware may still be using
the ringbuffer after the MI_USER_INTERRUPT to notify the seqno update
is executed.  The ringbuffer must remain pinned until the context save
is complete.  No longer pin and unpin ringbuffer in
populate_lr_context() - this transient address is meaningless and the
pinning can cause a sleep while atomic.

v4: Moved ringbuffer pin and unpin into the lr_context_pin functions.
Downgraded pinning check BUG_ONs to WARN_ONs.

v5: Reinstated WARN_ONs for unexpected execlist states.  Removed unused
variable.

Issue: VIZ-4277
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Signed-off-by: NThomas Daniel <thomas.daniel@intel.com>
Reviewed-by: NAkash Goel <akash.goels@gmail.com>
Reviewed-by: Deepak S<deepak.s@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

No longer create a work item to clean each execlist queue item.
Instead, move retired execlist requests to a queue and clean up the
items during retire_requests.

v2: Fix legacy ring path broken during overzealous cleanup

v3: Update idle detection to take execlists queue into account

v4: Grab execlist lock when checking queue state

v5: Fix leaking requests by freeing in execlists_retire_requests.

Issue: VIZ-4274
Signed-off-by: NThomas Daniel <thomas.daniel@intel.com>
Reviewed-by: NDeepak S <deepak.s@linux.intel.com>
Reviewed-by: NAkash Goel <akash.goels@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Following the legacy ring submission example, update the
ring->init_context() hook to support the execlist submission mode.

v2: update to use the new workaround macros and cleanup unused code.
This takes care of both bdw and chv workarounds.

v2.1: Add missing call to init_context() during deferred context creation.

v3: Split init_context (emit) in legacy/lrc modes. For lrc, get the ringbuf
from the context (Mika/Daniel).

v4: Merge init_context interfaces back, the legacy mode only needs the ring,
but the lrc mode needs the ring and context (Mika).

Issue: VIZ-4092
Issue: GMIN-3475
Change-Id: Ie3d093b2542ab0e2a44b90460533e2f979788d6c
Cc: Deepak S <deepak.s@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: NMichel Thierry <michel.thierry@intel.com>
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
[danvet: Align function paramater lists properly.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For BDW workarounds are currently initialized in init_clock_gating() but
they are lost during reset, suspend/resume etc; this patch moves the WAs
that are part of register state context to render ring init fn otherwise
default context ends up with incorrect values as they don't get initialized
until init_clock_gating fn.

v2: Add workarounds to golden render state
This method has its own issues, first of all this is different for
each gen and it is generated using a tool so adding new workaround
and mainitaining them across gens is not a straightforward process.

v3: Use LRIs to emit these workarounds (Ville)
Instead of modifying the golden render state the same LRIs are
emitted from within the driver.

v4: Use abstract name when exporting gen specific routines (Chris)

For: VIZ-4092
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Handle all context status events in the context status buffer on every
context switch interrupt. We only remove work from the execlist queue
after a context status buffer reports that it has completed and we only
attempt to schedule new contexts on interrupt when a previously submitted
context completes (unless no contexts are queued, which means the GPU is
free).

We canot call intel_runtime_pm_get() in an interrupt (or with a spinlock
grabbed, FWIW), because it might sleep, which is not a nice thing to do.
Instead, do the runtime_pm get/put together with the create/destroy request,
and handle the forcewake get/put directly.
Signed-off-by: NThomas Daniel <thomas.daniel@intel.com>

v2: Unreferencing the context when we are freeing the request might free
the backing bo, which requires the struct_mutex to be grabbed, so defer
unreferencing and freeing to a bottom half.

v3:
- Ack the interrupt inmediately, before trying to handle it (fix for
missing interrupts by Bob Beckett <robert.beckett@intel.com>).
- Update the Context Status Buffer Read Pointer, just in case (spotted
by Damien Lespiau).

v4: New namespace and multiple rebase changes.

v5: Squash with "drm/i915/bdw: Do not call intel_runtime_pm_get() in an
interrupt", as suggested by Daniel.
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
[danvet: Checkpatch ...]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Context switch (and execlist submission) should happen only when
other contexts are not active, otherwise pre-emption occurs.

To assure this, we place context switch requests in a queue and those
request are later consumed when the right context switch interrupt is
received (still TODO).

v2: Use a spinlock, do not remove the requests on unqueue (wait for
context switch completion).
Signed-off-by: NThomas Daniel <thomas.daniel@intel.com>

v3: Several rebases and code changes. Use unique ID.

v4:
- Move the queue/lock init to the late ring initialization.
- Damien's kmalloc review comments: check return, use sizeof(*req),
do not cast.

v5:
- Do not reuse drm_i915_gem_request. Instead, create our own.
- New namespace.

Signed-off-by: Michel Thierry <michel.thierry@intel.com> (v1)
Signed-off-by: Oscar Mateo <oscar.mateo@intel.com> (v2-v5)
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
[davnet: Checkpatch + wash-up s/BUG_ON/WARN_ON/.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The execlist patches have a bit a convoluted and long history and due
to that have the actual submission still misplaced deeply burried in
the low-level ringbuffer handling code. This design goes back to the
legacy ringbuffer code with its tricky lazy request and simple work
submissiion using ring tail writes. For that reason they need a
ring->ctx backpointer.

The goal is to unburry that code and move it up into a level where the
full execlist context is available so that we can ditch this
backpointer. Until that's done make it really obvious that there's
work still to be done.

Cc: Oscar Mateo <oscar.mateo@intel.com>
Cc: Thomas Daniel <thomas.daniel@intel.com>
Acked-by: NThomas Daniel <thomas.daniel@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Dispatch_execbuffer's evil twin.
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
[danvet: Ditch the check for aliasing ppgtt. It'll break soon and
execlists requires full ppgtt anyway.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We need to attend context switch interrupts from all rings. Also, fixed writing
IMR/IER and added HWSTAM at ring init time.

Notice that, if added to irq_enable_mask, the context switch interrupts would
be incorrectly masked out when the user interrupts are due to no users waiting
on a sequence number. Therefore, this commit adds a bitmask of interrupts to
be kept unmasked at all times.

v2: Disable HWSTAM, as suggested by Damien (nobody listens to these interrupts,
anyway).

v3: Add new get/put_irq functions.

Signed-off-by: Thomas Daniel <thomas.daniel@intel.com> (v1)
Signed-off-by: Oscar Mateo <oscar.mateo@intel.com> (v2 & v3)
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
[danvet: Drop the GEN8_ prefix from the context switch interrupt
define and move it to its brethren.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Same as the legacy-style ring->flush.

v2: The BSD invalidate bit still exists in GEN8! Add it for the VCS
rings (but still consolidate the blt and bsd ring flushes into one).
This was noticed by Brad Volkin.

v3: The command for BSD and for other rings is slightly different:
get it exactly the same as in gen6_ring_flush + gen6_bsd_ring_flush
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
[danvet: Checkpatch.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Very similar to the legacy add_request, only modified to account for
logical ringbuffer.

v2: Use MI_GLOBAL_GTT, as suggested by Brad Volkin.

v3: Unify render and non-render in the same function, as noticed by
Brad Volkin.
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Well, new-ish: if all this code looks familiar, that's because it's
a clone of the existing submission mechanism (with some modifications
here and there to adapt it to LRCs and Execlists).

And why did we do this instead of reusing code, one might wonder?
Well, there are some fears that the differences are big enough that
they will end up breaking all platforms.

Also, Execlists offer several advantages, like control over when the
GPU is done with a given workload, that can help simplify the
submission mechanism, no doubt. I am interested in getting Execlists
to work first and foremost, but in the future this parallel submission
mechanism will help us to fine tune the mechanism without affecting
old gens.

v2: Pass the ringbuffer only (whenever possible).
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
[danvet: Appease checkpatch. Again. And drop the legacy sarea gunk
that somehow crept in.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Logical rings do not need most of the initialization their
legacy ringbuffer counterparts do: we just need the pipe
control object for the render ring, enable Execlists on the
hardware and a few workarounds.

v2: Squash with: "drm/i915: Extract pipe control fini & make
init outside accesible".
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
[danvet: Make checkpatch happy.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Allocate and populate the default LRC for every ring, call
gen-specific init/cleanup, init/fini the command parser and
set the status page (now inside the LRC object). These are
things all engines/rings have in common.

Stopping the ring before cleanup and initializing the seqnos
is left as a TODO task (we need more infrastructure in place
before we can achieve this).

v2: Check the ringbuffer backing obj for ring_is_initialized,
instead of the context backing obj (similar, but not exactly
the same).
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Any given ringbuffer is unequivocally tied to one context and one engine.
By setting the appropriate pointers to them, the ringbuffer struct holds
all the infromation you might need to submit a workload for processing,
Execlists style.

v2: Drop ring->ctx since that looks terribly ill-defined for legacy
ringbuffer submission.

Signed-off-by: Oscar Mateo <oscar.mateo@intel.com> (v1)
Acked-by: Damien Lespiau <damien.lespiau@intel.com> (v2)
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

As we have said a couple of times by now, logical ring contexts have
their own ringbuffers: not only the backing pages, but the whole
management struct.

In a previous version of the series, this was achieved with two separate
patches:
drm/i915/bdw: Allocate ringbuffer backing objects for default global LRC
drm/i915/bdw: Allocate ringbuffer for user-created LRCs
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If the actual head has progressed forward inside a batch (request),
don't accumulate hangcheck score.

As the hangcheck score in increased only by acthd jumping backwards,
the result is that we only declare an active batch as stuck if it is
trapped inside a loop. Or that the looping will dominate the batch
progression so that it overcomes the bonus that forward progress gives.

v2: Improved commit message (Chris Wilson)
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
[danvet: s/active_loop/active (loop)/ as requested by Chris.]
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Again, it's low-level enough to simply take a ringbuf and nothing
else.

Trivial change.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Semaphore signalling works similarly to previous GENs with the exception
that the per ring mailboxes no longer exist. Instead you must define
your own space, somewhere in the GTT.

The comments in the code define the layout I've opted for, which should
be fairly future proof. Ie. I tried to define offsets in abstract terms
(NUM_RINGS, seqno size, etc).

NOTE: If one wanted to move this to the HWSP they could. I've decided
one 4k object would be easier to deal with, and provide potential wins
with cache locality, but that's all speculative.

v2: Update the macro to not need the other ring's ring->id (Chris)
Update the comment to use the correct formula (Chris)

v3: Move the macros the ringbuffer.h to prevent churn in next patch
(Ville)

v4: Fixed compilation rebase conflict
commit 1ec9e26d
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Fri Feb 14 14:01:11 2014 +0100

    drm/i915: Consolidate binding parameters into flags

v5: VCS2 rebase
Replace hweight_long with hweight32

v6 (Rodrigo): * Add missed VC2 gen8 ring signal init
   	      * fixing conflicst on rebase
    	      * minor fixes on address table
	      * remove WARN_ON
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
[danvet: s/BUG_ON/WARN_ON/]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

ring index calculation table was out of date after other rings were added,
although the formula is flexible and scale when adding new rings.

So this patch just update the comments and add a brief explanation
why to use sync_seqno[ring index].
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If a semaphore is waiting on another ring, which in turn happens to be
waiting on the first ring, but that second semaphore has been signalled,
we will be able to kick the second ring and so can treat the first ring
as a valid WAIT and not as HUNG.

v2: Be paranoid and cap the potential recursion depth whilst visiting
the semaphore signallers. (Mika)

References: https://bugs.freedesktop.org/show_bug.cgi?id=54226
References: https://bugs.freedesktop.org/show_bug.cgi?id=75502Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Up until now, contexts had one (and only one) backing object that was
used by the hardware to save/restore render ring contexts (via the
MI_SET_CONTEXT command). Other rings did not have or need this, so
our i915_hw_context struct had a 1:1 relationship with a a real HW
context.

With Logical Ring Contexts and Execlists, this is not possible anymore:
all rings need a backing object, and it cannot be reused. To prepare
for that, rename our contexts to the more generic term intel_context.

No functional changes.
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Manual cleanup after the previous Coccinelle script.

Yes, I could write another Coccinelle script to do this but I
don't want labor-replacing robots making an honest programmer's
work obsolete (also, I'm lazy).
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This refactoring has been performed using the following Coccinelle
semantic script:

    @@
    struct intel_engine_cs r;
    @@
    (
    - (r).obj
    + r.buffer->obj
    |
    - (r).virtual_start
    + r.buffer->virtual_start
    |
    - (r).head
    + r.buffer->head
    |
    - (r).tail
    + r.buffer->tail
    |
    - (r).space
    + r.buffer->space
    |
    - (r).size
    + r.buffer->size
    |
    - (r).effective_size
    + r.buffer->effective_size
    |
    - (r).last_retired_head
    + r.buffer->last_retired_head
    )

    @@
    struct intel_engine_cs *r;
    @@
    (
    - (r)->obj
    + r->buffer->obj
    |
    - (r)->virtual_start
    + r->buffer->virtual_start
    |
    - (r)->head
    + r->buffer->head
    |
    - (r)->tail
    + r->buffer->tail
    |
    - (r)->space
    + r->buffer->space
    |
    - (r)->size
    + r->buffer->size
    |
    - (r)->effective_size
    + r->buffer->effective_size
    |
    - (r)->last_retired_head
    + r->buffer->last_retired_head
    )

    @@
    expression E;
    @@
    (
    - LP_RING(E)->obj
    + LP_RING(E)->buffer->obj
    |
    - LP_RING(E)->virtual_start
    + LP_RING(E)->buffer->virtual_start
    |
    - LP_RING(E)->head
    + LP_RING(E)->buffer->head
    |
    - LP_RING(E)->tail
    + LP_RING(E)->buffer->tail
    |
    - LP_RING(E)->space
    + LP_RING(E)->buffer->space
    |
    - LP_RING(E)->size
    + LP_RING(E)->buffer->size
    |
    - LP_RING(E)->effective_size
    + LP_RING(E)->buffer->effective_size
    |
    - LP_RING(E)->last_retired_head
    + LP_RING(E)->buffer->last_retired_head
    )

Note: On top of this this patch also removes the now unused ringbuffer
fields in intel_engine_cs.
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
[danvet: Add note about fixup patch included here.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

As advanced by the previous patch, the ringbuffers and the engine
command streamers belong in different structs. This is so because,
while they used to be tightly coupled together, the new Logical
Ring Contexts (LRC for short) have a ringbuffer each.

In legacy code, we will use the buffer* pointer inside each ring
to get to the pertaining ringbuffer (the actual switch will be
done in the next patch). In the new Execlists code, this pointer
will be NULL and we will use instead the one inside the context
instead.
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In the upcoming patches we plan to break the correlation between
engine command streamers (a.k.a. rings) and ringbuffers, so it
makes sense to refactor the code and make the change obvious.

No functional changes.
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For clients that submit large batch buffers the command parser has
a substantial impact on performance. On my HSW ULT system performance
drops as much as ~20% on some tests. Most of the time is spent in the
command lookup code. Converting that from the current naive search to
a hash table lookup reduces the performance drop to ~10%.

The choice of value for I915_CMD_HASH_ORDER allows all commands
currently used in the parser tables to hash to their own bucket (except
for one collision on the render ring). The tradeoff is that it wastes
memory. Because the opcodes for the commands in the tables are not
particularly well distributed, reducing the order still leaves many
buckets empty. The increased collisions don't seem to have a huge
impact on the performance gain, but for now anyhow, the parser trades
memory for performance.

NB: Ville noticed that the error paths through the ring init code
will leak memory. I've not addressed that here. We can do a follow
up pass to handle all of the leaks.

v2: improved comment describing selection of hash key mask (Damien)
replace a BUG_ON() with an error return (Tvrtko, Ville)
commit message improvements
Signed-off-by: NBrad Volkin <bradley.d.volkin@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>