[PATCH v8 0/5] Add fdinfo support to Panfrost

[Adrián Larumbe]

This patch series adds fdinfo support to the Panfrost DRM driver. It will
display a series of key:value pairs under /proc/pid/fdinfo/fd for render
processes that open the Panfrost DRM file.

The pairs contain basic drm gpu engine and memory region information that
can either be cat by a privileged user or accessed with IGT's gputop
utility.

Changelog:

v1: https://lore.kernel.org/lkml/bb52b872-e41b-3894-285e-b52cfc849782@xxxxxxx/T/

v2: https://lore.kernel.org/lkml/20230901084457.5bc1ad69@xxxxxxxxxxxxx/T/
 - Changed the way gpu cycles and engine time are calculated, using GPU
   registers and taking into account potential resets.
 - Split render engine values into fragment and vertex/tiler ones.
 - Added more fine-grained calculation of RSS size for BO's.
 - Implemente selection of drm-memory region size units.
 - Removed locking of shrinker's mutex in GEM obj status function.

v3: https://lore.kernel.org/lkml/20230905184533.959171-1-adrian.larumbe@xxxxxxxxxxxxx/
 - Changed fdinfo engine names to something more descriptive.;
 - Mentioned GPU cycle counts aren't an exact measure.
 - Handled the case when job->priv might be NULL.
 - Handled 32 bit overflow of cycle register.
 - Kept fdinfo drm memory stats size unit display within 10k times the
   previous multiplier for more accurate BO size numbers.
 - Removed special handling of Prime imported BO RSS.
 - Use rss_size only for heap objects.
 - Use bo->base.madv instead of specific purgeable flag.
 - Fixed kernel test robot warnings.

v4: https://lore.kernel.org/lkml/20230912084044.955864-1-adrian.larumbe@xxxxxxxxxxxxx/
 - Move cycle counter get and put to panfrost_job_hw_submit and
   panfrost_job_handle_{err,done} for more accuracy.
 - Make sure cycle counter refs are released in reset path
 - Drop the model param for toggling cycle counting and do
   leave it down to the debugfs file.
 - Don't disable cycle counter when togglint debugfs file,
   let refcounting logic handle it instead.
 - Remove fdinfo data nested structure definion and 'names' field
 - When incrementing BO RSS size in GPU MMU page fault IRQ handler, assume
   granuality of 2MiB for every successful mapping.
 - drm-file picks an fdinfo memory object size unit that doesn't lose precision.

v5: https://lore.kernel.org/lkml/20230914223928.2374933-1-adrian.larumbe@xxxxxxxxxxxxx/
 - Removed explicit initialisation of atomic variable for profiling mode,
   as it's allocated with kzalloc.
 - Pass engine utilisation structure to jobs rather than the file context, to avoid
   future misusage of the latter.
 - Remove double reading of cycle counter register and ktime in job deqeueue function,
   as the scheduler will make sure these values are read over in case of requeuing.
 - Moved putting of cycle counting refcnt into panfrost job dequeue.
   function to avoid repetition.

v6: https://lore.kernel.org/lkml/c73ad42b-a8db-23c2-86c7-1a2939dba044@xxxxxxxxxxxxxxx/T/
 - Fix wrong swapped-round engine time and cycle values in fdinfo
   drm print statements.

v7: https://lore.kernel.org/lkml/20230927213133.1651169-6-adrian.larumbe@xxxxxxxxxxxxx/T/
 - Make sure an object's actual RSS size is added to the overall fdinfo's purgeable
   and active size tally when it's both resident and purgeable or active.
 - Create a drm/panfrost.rst documentation file with meaning of fdinfo strings.
 - BUILD_BUG_ON checking the engine name array size for fdinfo.
 - Added copyright notices for Amazon in Panfrost's new debugfs files.
 - Discarded fdinfo memory stats unit size selection patch.

v8:
 - Style improvements and addressing nitpicks.         

Adrián Larumbe (5):
  drm/panfrost: Add cycle count GPU register definitions
  drm/panfrost: Add fdinfo support GPU load metrics
  drm/panfrost: Add fdinfo support for memory stats
  drm/drm_file: Add DRM obj's RSS reporting function for fdinfo
  drm/panfrost: Implement generic DRM object RSS reporting function

 Documentation/gpu/drm-usage-stats.rst       |  1 +
 Documentation/gpu/panfrost.rst              | 38 +++++++++++++
 drivers/gpu/drm/drm_file.c                  |  8 +--
 drivers/gpu/drm/panfrost/Makefile           |  2 +
 drivers/gpu/drm/panfrost/panfrost_debugfs.c | 21 ++++++++
 drivers/gpu/drm/panfrost/panfrost_debugfs.h | 14 +++++
 drivers/gpu/drm/panfrost/panfrost_devfreq.c |  8 +++
 drivers/gpu/drm/panfrost/panfrost_devfreq.h |  3 ++
 drivers/gpu/drm/panfrost/panfrost_device.c  |  2 +
 drivers/gpu/drm/panfrost/panfrost_device.h  | 13 +++++
 drivers/gpu/drm/panfrost/panfrost_drv.c     | 60 ++++++++++++++++++++-
 drivers/gpu/drm/panfrost/panfrost_gem.c     | 30 +++++++++++
 drivers/gpu/drm/panfrost/panfrost_gem.h     |  5 ++
 drivers/gpu/drm/panfrost/panfrost_gpu.c     | 41 ++++++++++++++
 drivers/gpu/drm/panfrost/panfrost_gpu.h     |  4 ++
 drivers/gpu/drm/panfrost/panfrost_job.c     | 24 +++++++++
 drivers/gpu/drm/panfrost/panfrost_job.h     |  5 ++
 drivers/gpu/drm/panfrost/panfrost_mmu.c     |  1 +
 drivers/gpu/drm/panfrost/panfrost_regs.h    |  5 ++
 include/drm/drm_gem.h                       |  9 ++++
 20 files changed, 290 insertions(+), 4 deletions(-)
 create mode 100644 Documentation/gpu/panfrost.rst
 create mode 100644 drivers/gpu/drm/panfrost/panfrost_debugfs.c
 create mode 100644 drivers/gpu/drm/panfrost/panfrost_debugfs.h


base-commit: f45acf7acf75921c0409d452f0165f51a19a74fd
-- 
2.42.0