[PATCH v3 0/1] Add support for EU stall sampling

[Harish Chegondi]

The following patch adds support for EU stall sampling, a new hardware
feature first added in PVC and is being supported in XE2 and later
architecture GPUs. This feature would enable capturing of EU stall
data which include the IP address of the instruction stalled and
various stall reason counts. More details are explained in the patch
commit message.

Support for this feature is being added into Mesa.
https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30142

A new test in the IGT repo: 
https://gitlab.freedesktop.org/drm/igt-gpu-tools.git
is also under development to test this feature in the driver. This
patch has undergone basic testing with the new IGT test that is under
development.

Thank You.

v3: a. Removed data header and changed read() to return -EIO when data is dropped by the HW.
    b. Added a new DRM_XE_OBSERVATION_IOCTL_INFO to query EU stall data record info
    c. Added struct drm_xe_eu_stall_data_pvc and struct drm_xe_eu_stall_data_xe2
       to xe_drm.h. These declarations would help user space to parse the
       EU stall data
    d. Addressed other review comments from v2
v2: Rename xe perf layer as xe observation layer (Ashutosh)

Harish Chegondi (1):
  drm/xe/eustall: Add support for EU stall sampling

 drivers/gpu/drm/xe/Makefile                |    1 +
 drivers/gpu/drm/xe/regs/xe_eu_stall_regs.h |   33 +
 drivers/gpu/drm/xe/xe_eustall_cntr.c       | 1000 ++++++++++++++++++++
 drivers/gpu/drm/xe/xe_eustall_cntr.h       |   60 ++
 drivers/gpu/drm/xe/xe_gt.c                 |    6 +
 drivers/gpu/drm/xe/xe_gt_topology.c        |    9 +
 drivers/gpu/drm/xe/xe_gt_topology.h        |    3 +
 drivers/gpu/drm/xe/xe_gt_types.h           |    3 +
 drivers/gpu/drm/xe/xe_observation.c        |   14 +
 drivers/gpu/drm/xe/xe_trace.h              |   35 +
 include/uapi/drm/xe_drm.h                  |  134 +++
 11 files changed, 1298 insertions(+)
 create mode 100644 drivers/gpu/drm/xe/regs/xe_eu_stall_regs.h
 create mode 100644 drivers/gpu/drm/xe/xe_eustall_cntr.c
 create mode 100644 drivers/gpu/drm/xe/xe_eustall_cntr.h

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2.45.1