[Intel-gfx] [PATCH 0/9 v6] Batch submission via GuC

[Dave Gordon]

On 12/08/15 15:43, Dave Gordon wrote:
> This patch series enables command submission via the GuC. In this mode,
> instead of the host CPU driving the execlist port directly, it hands
> over work items to the GuC, using a doorbell mechanism to tell the GuC
> that new items have been added to its work queue. The GuC then dispatches
> contexts to the various GPU engines, and manages the resulting context-
> switch interrupts. Completion of a batch is however still signalled to
> the CPU; the GuC is not involved in handling user interrupts.
>
> There are two subsequences within the patch series:
>
>    drm/i915: GuC-specific firmware loader
>    drm/i915: Debugfs interface to read GuC load status
>
> These two patches provide the GuC loader and a debugfs interface to
> verify the resulting state.  At this point in the sequence we can load
> and activate the GuC firmware, but not submit any batches through it.
> (This is nonetheless a potentially useful state, as the GuC could do
> other useful work even when not handling batch submissions).
>
>    drm/i915: Expose one LRC function for GuC submission mode
>    drm/i915: Prepare for GuC-based command submission
>    drm/i915: Enable GuC firmware log
>    drm/i915: Implementation of GuC submission client
>    drm/i915: Interrupt routing for GuC submission
>    drm/i915: Integrate GuC-based command submission
>    drm/i915: Debugfs interface for GuC submission statistics
>
> In this second section, we implement the GuC submission mechanism, and
> link it into the (execlist-based) submission path. At this stage, it is
> not yet enabled by default; it is activated only if the kernel command
> line explicitly switches it on.
>
> The GuC firmware itself is not included in this patchset; it is or will
> be available for download from https://01.org/linuxgraphics/downloads/
> This driver works with and requires GuC firmware revision 3.x. It will
> not work with any firmware version 1.x, as the GuC protocol in those
> revisions was incompatible and is no longer supported.
>
> On platforms where there is no GuC, or where GuC submission is not
> specifically enabled, batch submission will continue to use the execlist
> (or ringbuffer) mechanisms.  On the other hand, if GuC submission is
> requested but the GuC firmware cannot be found or is invalid, the GPU
> will be unusable.
>
> It is expected that a subsequent patch will enable GuC submission by
> default once the signed firmware is published on 01.org.
>
> Ben Widawsky (0):
> Vinit Azad (0):
> Michael H. Nguyen (0):
>    created the original versions on which some of these patches are based.
>
> Alex Dai (5):
>    drm/i915: GuC-specific firmware loader
>    drm/i915: Debugfs interface to read GuC load status
>    drm/i915: Prepare for GuC-based command submission
>    drm/i915: Enable GuC firmware log
>    drm/i915: Integrate GuC-based command submission
>
> Dave Gordon (4):
>    drm/i915: Expose one LRC function for GuC submission mode
>    drm/i915: Implementation of GuC submission client
>    drm/i915: Interrupt routing for GuC submission
>    drm/i915: Debugfs interface for GuC submission statistics
>
>   Documentation/DocBook/drm.tmpl             |  14 +
>   drivers/gpu/drm/i915/Makefile              |   4 +
>   drivers/gpu/drm/i915/i915_debugfs.c        | 146 ++++-
>   drivers/gpu/drm/i915/i915_dma.c            |   9 +
>   drivers/gpu/drm/i915/i915_drv.h            |  11 +
>   drivers/gpu/drm/i915/i915_gem.c            |  16 +
>   drivers/gpu/drm/i915/i915_gpu_error.c      |  14 +-
>   drivers/gpu/drm/i915/i915_guc_reg.h        |  17 +-
>   drivers/gpu/drm/i915/i915_guc_submission.c | 901 +++++++++++++++++++++++++++++
>   drivers/gpu/drm/i915/i915_reg.h            |  15 +-
>   drivers/gpu/drm/i915/intel_guc.h           | 122 ++++
>   drivers/gpu/drm/i915/intel_guc_fwif.h      |   9 +-
>   drivers/gpu/drm/i915/intel_guc_loader.c    | 611 +++++++++++++++++++
>   drivers/gpu/drm/i915/intel_lrc.c           |  65 ++-
>   drivers/gpu/drm/i915/intel_lrc.h           |   8 +
>   15 files changed, 1918 insertions(+), 44 deletions(-)
>   create mode 100644 drivers/gpu/drm/i915/i915_guc_submission.c
>   create mode 100644 drivers/gpu/drm/i915/intel_guc.h
>   create mode 100644 drivers/gpu/drm/i915/intel_guc_loader.c

Tom O'Rourke has already R-B'ed the previous [v5] versions of these, and 
there are no substantive changes to patches 2, 3, 4, 5, 7 and 8, so we 
can carry that over; also, the change in patch 1 is just an update to a 
comment noted in Tom's earlier reviews as being out-of-date.

I haven't included patch 10 (enable-by-default) as we've decided to wait 
until the signed firmware is publicly available on 01.org before
making it the default.

So, it's really just patches 6/9 and 9/9 that need a re-review from Tom.

Thanks,
.Dave.