[Intel-gfx] [RFC 0/6] Start separating GuC and execlists submission

[Daniele Ceraolo Spurio]

Note: this applies on top of my series to commit early to GuC [1].

Picking up from the feedback from my RFC series about splitting
up intel_lrc.c [2], this series introduces GuC submission versions
of most of the engine and context functions. As a starting point,
the functions are still very similar to the execlists ones, but
they will progressively diverge while we add the new submission
logic. Some of the functions have been simplified by removing
support for pre-gen11 cases as we only aim to enable GuC submission
for gen11+; I've left comments and BUG_ONs to mark the reduces
support spots to easily find them in case we ever want to enable
GuC submission for older gens.

Going slightly against the feedback from the previous series, I have
kept the basic context and ring object management shared between
execlists and GuC submission functions. The rationale is that those
objects are HW-related and therefore their creation and their main
attributes (e.g. context size) are not dependent on the submission
method in any way. Handling of more SW constructs, like the timeline,
has been duplicated.

Still in theme of sharing, the flush and bb_start functions have also
been re-used on the GuC side, but I'm not sure if keeping them in
intel_lrc.c is the best solution. My medium-term plan is still the same
as [2], i.e. split execlists_submission.c out of intel_lrc.c, with the
latter holding the common code, but it might be worth moving the
command emission to a dedicated file or to a header as inlines, like
we already do in some cases.

The code is still a bit rough and the series has been compile-tested
only. I wanted to get some early comments about the direction before
rebasing the rest of the GuC code on top of it and start testing.

[1] https://patchwork.freedesktop.org/series/72031/
[2] https://patchwork.freedesktop.org/series/70787/

Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: John Harrison <John.C.Harrison at Intel.com>
Cc: Matthew Brost <matthew.brost at intel.com>

Daniele Ceraolo Spurio (6):
  drm/i915/guc: Add guc-specific breadcrumb functions
  drm/i915/guc: Add request_alloc for guc_submission
  drm/i915/guc: Add engine->resume for GuC submission
  drm/i915/guc: Re-use lrc flush functions
  drm/i915/guc: Add initial context ops for GuC submission
  drm/i915/guc: Stop inheriting from execlists_set_default_submission

 drivers/gpu/drm/i915/gt/intel_lrc.c           | 217 +++++-----
 drivers/gpu/drm/i915/gt/intel_lrc.h           |  17 +-
 drivers/gpu/drm/i915/gt/selftest_lrc.c        |  12 +-
 .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 378 +++++++++++++++++-
 4 files changed, 496 insertions(+), 128 deletions(-)

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