[Intel-gfx] [PATCH v4 00/18] 48-bit PPGTT

Michel Thierry michel.thierry at intel.com
Tue Jul 7 08:14:45 PDT 2015


These are the rebased patches, after Mika's final ppgtt clean-up series landed
(it relies in the macros added) and Akash review comments.

In order expand the GPU address space, a 4th level translation is added, the
Page Map Level 4 (PML4). This PML4 has 256 PML4 Entries (PML4E), PML4[0-255],
each pointing to a PDP. All the existing "dynamic alloc ppgtt" functions are
used, only adding the 4th level changes. I also updated some remaining
variables that were 32b only.

There are 2 hardware workarounds needed to allow correct operation with 48b
addresses (Wa32bitGeneralStateOffset & Wa32bitInstructionBaseOffset). This
new patchset version includes the comments and suggestions from Chris Wilson.
A flag (EXEC_OBJECT_SUPPORTS_48B_ADDRESS) will indicate if a given object can be
allocated outside the first 4 PDPs; if not, the end range is forced to 4GB. Also,
more objects now use the DRM_MM_CREATE_TOP flag. To maintain compatibility, in
libdrm I added a new drm_intel_bo_emit_reloc_48bit function that will flag
these objects, while the existing drm_intel_bo_emit_reloc clears it.

Finally, this feature is only available in BDW and Gen9, requires LRC submission
mode (execlists) and it can be detected by i915.enable_ppgtt=3.

Also note that this expanded address space is only available for full PPGTT,
aliasing PPGTT and Global GTT remain 32-bit.
Michel Thierry (18):
  drm/i915: Remove unnecessary gen8_clamp_pd
  drm/i915/gen8: Make pdp allocation more dynamic
  drm/i915/gen8: Add PML4 structure
  drm/i915/gen8: Abstract PDP usage
  drm/i915/gen8: Add dynamic page trace events
  drm/i915/gen8: implement alloc/free for 4lvl
  drm/i915/gen8: Add 4 level switching infrastructure and lrc support
  drm/i915/gen8: Generalize PTE writing for GEN8 PPGTT
  drm/i915/gen8: Pass sg_iter through pte inserts
  drm/i915/gen8: Add 4 level support in insert_entries and clear_range
  drm/i915/gen8: Initialize PDPs
  drm/i915: Expand error state's address width to 64b
  drm/i915/gen8: Add ppgtt info and debug_dump
  drm/i915: object size needs to be u64
  drm/i915: batch_obj vm offset must be u64
  drm/i915/userptr: Kill user_size limit check
  drm/i915: Wa32bitGeneralStateOffset & Wa32bitInstructionBaseOffset
  drm/i915/gen8: Flip the 48b switch

 drivers/gpu/drm/i915/i915_debugfs.c        |  18 +-
 drivers/gpu/drm/i915/i915_drv.h            |  15 +-
 drivers/gpu/drm/i915/i915_gem.c            |  19 +-
 drivers/gpu/drm/i915/i915_gem_execbuffer.c |  13 +
 drivers/gpu/drm/i915/i915_gem_gtt.c        | 609 ++++++++++++++++++++++++-----
 drivers/gpu/drm/i915/i915_gem_gtt.h        |  63 ++-
 drivers/gpu/drm/i915/i915_gem_userptr.c    |   4 -
 drivers/gpu/drm/i915/i915_gpu_error.c      |  18 +-
 drivers/gpu/drm/i915/i915_params.c         |   2 +-
 drivers/gpu/drm/i915/i915_reg.h            |   1 +
 drivers/gpu/drm/i915/i915_trace.h          |  32 +-
 drivers/gpu/drm/i915/intel_lrc.c           |  65 ++-
 include/uapi/drm/i915_drm.h                |   3 +-
 13 files changed, 694 insertions(+), 168 deletions(-)

-- 
2.4.5



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