[Intel-gfx] [RFC 00/12] Convert requests to use struct fence

[John.C.Harrison at Intel.com]

From: John Harrison <John.C.Harrison at Intel.com>

There is a construct in the linux kernel called 'struct fence' that is
intended to keep track of work that is executed on hardware. I.e. it
solves the basic problem that the drivers 'struct
drm_i915_gem_request' is trying to address. The request structure does
quite a lot more than simply track the execution progress so is very
definitely still required. However, the basic completion status side
could be updated to use the ready made fence implementation and gain
all the advantages that provides.

Using the struct fence object also has the advantage that the fence
can be used outside of the i915 driver (by other drivers or by
userland applications). That is the basis of the dma-buff
synchronisation API and allows asynchronous tracking of work
completion. In this case, it allows applications to be signalled
directly when a batch buffer completes without having to make an IOCTL
call into the driver.

This is work that was planned since the conversion of the driver from
being seqno value based to being request structure based. This patch
series does that work.

An IGT test to exercise the fence support from user land is in
progress and will follow. Android already makes extensive use of
fences for display composition. Real world linux usage is planned in
the form of Jesse's page table sharing / bufferless execbuf support.
There is also a plan that Wayland (and others) could make use of it in
a similar manner to Android.

v2: Updated for review comments by various people and to add support
for Android style 'native sync'.

v3: Updated from review comments by Tvrtko Ursulin. Also moved sync
framework out of staging and improved request completion handling.

[Patches against drm-intel-nightly tree fetched 17/11/2015]

John Harrison (9):
  staging/android/sync: Move sync framework out of staging
  drm/i915: Convert requests to use struct fence
  drm/i915: Removed now redudant parameter to i915_gem_request_completed()
  drm/i915: Add per context timelines to fence object
  drm/i915: Delay the freeing of requests until retire time
  drm/i915: Interrupt driven fences
  drm/i915: Updated request structure tracing
  drm/i915: Add sync framework support to execbuff IOCTL
  drm/i915: Cache last IRQ seqno to reduce IRQ overhead

Maarten Lankhorst (1):
  staging/android/sync: add sync_fence_create_dma

Peter Lawthers (1):
  android/sync: Fix reversed sense of signaled fence

Tvrtko Ursulin (1):
  staging/android/sync: Support sync points created from dma-fences

 drivers/android/Kconfig                    |  28 ++
 drivers/android/Makefile                   |   2 +
 drivers/android/sw_sync.c                  | 260 ++++++++++
 drivers/android/sw_sync.h                  |  59 +++
 drivers/android/sync.c                     | 734 +++++++++++++++++++++++++++++
 drivers/android/sync.h                     | 387 +++++++++++++++
 drivers/android/sync_debug.c               | 256 ++++++++++
 drivers/android/trace/sync.h               |  82 ++++
 drivers/gpu/drm/i915/Kconfig               |   3 +
 drivers/gpu/drm/i915/i915_debugfs.c        |   7 +-
 drivers/gpu/drm/i915/i915_drv.h            |  75 +--
 drivers/gpu/drm/i915/i915_gem.c            | 437 ++++++++++++++++-
 drivers/gpu/drm/i915/i915_gem_context.c    |  15 +-
 drivers/gpu/drm/i915/i915_gem_execbuffer.c |  95 +++-
 drivers/gpu/drm/i915/i915_irq.c            |   2 +-
 drivers/gpu/drm/i915/i915_trace.h          |  13 +-
 drivers/gpu/drm/i915/intel_display.c       |   4 +-
 drivers/gpu/drm/i915/intel_lrc.c           |  13 +
 drivers/gpu/drm/i915/intel_pm.c            |   6 +-
 drivers/gpu/drm/i915/intel_ringbuffer.c    |   5 +
 drivers/gpu/drm/i915/intel_ringbuffer.h    |   9 +
 drivers/staging/android/Kconfig            |  28 --
 drivers/staging/android/Makefile           |   2 -
 drivers/staging/android/sw_sync.c          | 260 ----------
 drivers/staging/android/sw_sync.h          |  59 ---
 drivers/staging/android/sync.c             | 729 ----------------------------
 drivers/staging/android/sync.h             | 356 --------------
 drivers/staging/android/sync_debug.c       | 254 ----------
 drivers/staging/android/trace/sync.h       |  82 ----
 drivers/staging/android/uapi/sw_sync.h     |  32 --
 drivers/staging/android/uapi/sync.h        |  97 ----
 include/uapi/Kbuild                        |   1 +
 include/uapi/drm/i915_drm.h                |  16 +-
 include/uapi/sync/Kbuild                   |   3 +
 include/uapi/sync/sw_sync.h                |  32 ++
 include/uapi/sync/sync.h                   |  97 ++++
 36 files changed, 2569 insertions(+), 1971 deletions(-)
 create mode 100644 drivers/android/sw_sync.c
 create mode 100644 drivers/android/sw_sync.h
 create mode 100644 drivers/android/sync.c
 create mode 100644 drivers/android/sync.h
 create mode 100644 drivers/android/sync_debug.c
 create mode 100644 drivers/android/trace/sync.h
 delete mode 100644 drivers/staging/android/sw_sync.c
 delete mode 100644 drivers/staging/android/sw_sync.h
 delete mode 100644 drivers/staging/android/sync.c
 delete mode 100644 drivers/staging/android/sync.h
 delete mode 100644 drivers/staging/android/sync_debug.c
 delete mode 100644 drivers/staging/android/trace/sync.h
 delete mode 100644 drivers/staging/android/uapi/sw_sync.h
 delete mode 100644 drivers/staging/android/uapi/sync.h
 create mode 100644 include/uapi/sync/Kbuild
 create mode 100644 include/uapi/sync/sw_sync.h
 create mode 100644 include/uapi/sync/sync.h

-- 
1.9.1