[PATCH v8 0/5] Support fdinfo runtime and memory stats on Panthor

[Adrián Larumbe]

This patch series enables userspace utilities like gputop and nvtop to query a
render context's fdinfo file and figure out rates of engine and memory utilisation.

Previous discussion can be found at
https://lore.kernel.org/dri-devel/20240920234436.207563-1-adrian.larumbe@collabora.com/

Changelog:
v8:
 - Fixed uninitialised stack variable bug that was triggering an invalid memory reference.
 - Added a few R-b tags to commits
v7:
 - Fixed some kernel test bot-reported documentation and sign mismatch errors.
 - Defined convenience macros for specifying CS instructions according to their profiled status.
 - Explicitly initialised instruction count for structure containing a job's
 instructions when calculating its amount of credits for the scheduler.
 - Some minor cosmetic nits. 
v6:
 - Addressed some nits and style issues.
 - Enforced static assert equality of instruction buffer when calculating job
 credits or copying them into the ringbuffer.
 - Added explanation to the way in which job credits and profiled job size is done.
 - Broke down fdinfo enablement patch into two, one of them dealing with adding
 support for calculating the current and top operating device frequencies
 - Fixed race at the time drm file-wide profiling stats are gathered from groups.
v5:
 - Moved profiling information slots into a per-queue BO and away from syncobjs.
 - Decide on size of profiling slots BO from size of CS for minimal profiled job
 - Turn job and device profiling flag into a bit mask so that individual metrics
 can be enabled separately.
 - Shrunk ringbuffer slot size to that of a cache line.
 - Track profiling slot indeces separately from the job's queue ringbuffer's
 - Emit CS instructions one by one and tag them depending on profiling mask
 - New helper for calculating job credits depending on profiling flags
 - Add Documentation file for sysfs profiling knob
 - fdinfo will only show engines or cycles tags if these are respectively enabled.
v4:
 - Fixed wrong assignment location for frequency values in Panthor's devfreq
 - Removed the last two commits about registering size of internal BO's
 - Rearranged patch series so that sysfs knob is done last and all the previous
 time sampling and fdinfo show dependencies are already in place
v3:
 - Fixed some nits and removed useless bounds check in panthor_sched.c
 - Added support for sysfs profiling knob and optional job accounting
 - Added new patches for calculating size of internal BO's
v2:
 - Split original first patch in two, one for FW CS cycle and timestamp
 calculations and job accounting memory management, and a second one
 that enables fdinfo.
 - Moved NUM_INSTRS_PER_SLOT to the file prelude
 - Removed nelem variable from the group's struct definition.
 - Precompute size of group's syncobj BO to avoid code duplication.
 - Some minor nits.

Adrián Larumbe (5):
  drm/panthor: introduce job cycle and timestamp accounting
  drm/panthor: record current and maximum device clock frequencies
  drm/panthor: add DRM fdinfo support
  drm/panthor: enable fdinfo for memory stats
  drm/panthor: add sysfs knob for enabling job profiling

 .../testing/sysfs-driver-panthor-profiling    |  10 +
 Documentation/gpu/panthor.rst                 |  46 +++
 drivers/gpu/drm/panthor/panthor_devfreq.c     |  18 +-
 drivers/gpu/drm/panthor/panthor_device.h      |  36 ++
 drivers/gpu/drm/panthor/panthor_drv.c         |  73 ++++
 drivers/gpu/drm/panthor/panthor_gem.c         |  12 +
 drivers/gpu/drm/panthor/panthor_sched.c       | 384 +++++++++++++++---
 drivers/gpu/drm/panthor/panthor_sched.h       |   2 +
 8 files changed, 531 insertions(+), 50 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-driver-panthor-profiling
 create mode 100644 Documentation/gpu/panthor.rst

-- 
2.46.0