Re: [Intel-gfx] [PATCH v5 0/1] drm/i915/pxp: Prepare intel_pxp entry points for MTL

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Mon, Nov 28, 2022 at 04:31:51PM -0800, Alan Previn wrote:
> MTL has two tiles that is represented by the intel_gt structure in the i915
> code. The PXP feature has a control-structure that currently hangs off the
> intel_gt structure. In MTL, the standalone media tile (i.e. not the root
> tile) contains the VDBOX and KCR engine which are among several assets
> that PXP relies on for establishing and tearing down the PXP session.
> 
> However PXP is a global feature as other engines on other tiles can reference
> the PXP session in an object's info within batch buffer instructions. That
> coherrency is handled implicitly by the HW. In fact, for the forseeable future,
> we are expecting this link whereby only one of the tiles will be the control-gt
> for the PXP subsystem.
> 
> Keeping the intel_pxp structure within the intel_gt structure makes some
> internal functionalities more straight forward but adds code complexity to
> code readibility and maintainibility to many external-to-pxp subsystems
> which may need to pick the correct intel_gt structure. An example of this
> would be the intel_pxp_is_active or intel_pxp_is_enabled functionality which
> should be viewed as a global level inquiry, not a per-gt inquiry.
> 
> That said, this series promotes the intel_pxp structure into the
> drm_i915_private structure making it a top-level subsystem and the PXP
> subsystem will select the control gt internally and keep a pointer to
> it for internal reference.

In general, no need for cover letter in single/standalone patches.
In this case, I believe this here is a very good information to be on the
commit message. It looks more complete and informative for later history,
then the current one.

> 
> Changes from prior revs:
>    v4: - Instead of maintaining intel_pxp as an intel_gt structure member and
>          creating a number of convoluted helpers that takes in i915 as input
>          and redirects to the correct intel_gt or takes any intel_gt and internally
>          replaces with the correct intel_gt, promote it to be a top-level i915
>          structure.
>    v3: - Rename gt level helper functions to "intel_pxp_is_enabled/supported/
>          active_on_gt" (Daniele)
>        - Upgrade _gt_supports_pxp to replace what was intel_gtpxp_is_supported
>          as the new intel_pxp_is_supported_on_gt to check for PXP feature
>          support vs the tee support for huc authentication. Fix pxp-debugfs-
>          registration to use only the former to decide support. (Daniele)
>        - Couple minor optimizations.
>    v2: - Avoid introduction of new device info or gt variables and use
>          existing checks / macros to differentiate the correct GT->PXP
>          control ownership (Daniele Ceraolo Spurio)
>        - Don't reuse the updated global-checkers for per-GT callers (such
>          as other files within PXP) to avoid unnecessary GT-reparsing,
>          expose a replacement helper like the prior ones. (Daniele).
>    v1: Add one more patch to the series for the intel_pxp suspend/resume
>        for similiar refactoring
> 
> Alan Previn (1):
>   drm/i915/pxp: Promote pxp subsystem to top-level of i915
> 
>  .../drm/i915/display/skl_universal_plane.c    |  2 +-
>  drivers/gpu/drm/i915/gem/i915_gem_context.c   |  6 +-
>  drivers/gpu/drm/i915/gem/i915_gem_create.c    |  2 +-
>  .../gpu/drm/i915/gem/i915_gem_execbuffer.c    |  2 +-
>  drivers/gpu/drm/i915/gt/intel_gt.c            |  5 --
>  drivers/gpu/drm/i915/gt/intel_gt_debugfs.c    |  1 -
>  drivers/gpu/drm/i915/gt/intel_gt_irq.c        |  2 +-
>  drivers/gpu/drm/i915/gt/intel_gt_pm.c         |  8 ---
>  drivers/gpu/drm/i915/gt/intel_gt_types.h      |  3 -
>  drivers/gpu/drm/i915/gt/uc/intel_huc_fw.c     |  2 +-
>  drivers/gpu/drm/i915/i915_driver.c            | 20 ++++++
>  drivers/gpu/drm/i915/i915_drv.h               |  3 +
>  drivers/gpu/drm/i915/pxp/intel_pxp.c          | 72 ++++++++++++++-----
>  drivers/gpu/drm/i915/pxp/intel_pxp.h          |  6 +-
>  drivers/gpu/drm/i915/pxp/intel_pxp_cmd.c      |  8 ++-
>  drivers/gpu/drm/i915/pxp/intel_pxp_debugfs.c  | 41 +++++++----
>  drivers/gpu/drm/i915/pxp/intel_pxp_debugfs.h  |  4 +-
>  drivers/gpu/drm/i915/pxp/intel_pxp_irq.c      | 10 ++-
>  drivers/gpu/drm/i915/pxp/intel_pxp_pm.c       |  4 +-
>  drivers/gpu/drm/i915/pxp/intel_pxp_tee.c      |  8 ++-
>  drivers/gpu/drm/i915/pxp/intel_pxp_types.h    | 11 +++
>  21 files changed, 150 insertions(+), 70 deletions(-)
> 
> 
> base-commit: d21d6474a37e5d43075a24668807ea40a7ee9fc1
> -- 
> 2.34.1
>