[PATCH v3 0/7] drm/xe: Capture additional HW register state in devcoredump

[Nareshkumar Gollakoti <naresh.kumar.g@intel.com>]

This series extends the Xe devcoredump with additional hardware register
state to improve post-mortem debugging of GPU hangs and faults on Xe3p.

Today the devcoredump captures GuC log/CT, engine and submission state.
When triaging hangs it is often necessary to also know the static HW
configuration (fuses), GuC status/error state, GAM page-fault reporting
and L3 node status at the time of the hang. Collecting these at capture
time makes the dump self-contained and avoids relying on separate
probe-time logging.

To do this, the series adds a small generic MMIO register-dump helper
(descriptor list -> snapshot -> print/free) and uses it for several
register groups. Each group is captured for both the primary GT and,
where applicable, the media GT, and is gated to Xe3p (GRAPHICS_VER >= 35).
Registers requiring MCR steering are read through
xe_gt_mcr_unicast_read_any(); the remaining GAM registers use INSTANCE0
default steering and are read directly.

Snapshots are allocated with GFP_ATOMIC as capture runs inside the
dma_fence signalling section, matching the surrounding captures, and are
freed in the existing devcoredump teardown path.

Patches:
  1  Add the generic reg-dump helpers and capture GT/media fuse registers.
  2  Capture GT and media GuC status/error registers.
  3  Print register offsets alongside names in the GuC engine capture
     output (32- and 64-bit), easing cross-reference with the bspec.
  4  Capture the GAM page-fault report head/tail registers.
  5  Add the TDL gfx registers to the XeHPG extended GuC capture list.
  6  Capture L3 node status registers (MCR, read via unicast_read_any()).

Sample devcoredump output gains the following sections:
  **** GT Fuse Register Dump ****
  **** Media GT Fuse Register Dump ****
  **** GT GuC Register Dump ****
  **** Media GT GuC Register Dump ****
  **** GAM PF Report ****
  **** Node Status ****
  ****  Additional engine state registers ****

v3:(Sashiko)
- Use the LOW_DW MMIO offset when printing combined 64-bit register values
  in capture snapshots
- Preserve the existing coredump register-name format and append register
  address as trailing metadata
- Replace the render is not awake message with raw POWERGATE_ENABLE
  bit-state output
- Move engine-class-specific registers out of COMMON_BASE_ENGINE_INSTANCE
  into class-specific capture lists

Nareshkumar Gollakoti (7):
  drm/xe/devcoredump: Capture GT fuse registers in devcoredump
  drm/xe/devcoredump: Add GuC register snapshot to devcoredump
  drm/xe/guc: Print register addresses in capture snapshot output
  drm/xe: dump GAM page fault report registers in devcoredump
  drm/xe/guc: add TDL,SLICE gfx registers to capture list
  drm/xe: capture L3 node status registers in devcoredump
  drm/xe/guc: capture additional engine state registers

 drivers/gpu/drm/xe/regs/xe_engine_regs.h  |  22 ++
 drivers/gpu/drm/xe/regs/xe_gt_regs.h      |  15 +
 drivers/gpu/drm/xe/regs/xe_guc_regs.h     |   5 +
 drivers/gpu/drm/xe/xe_devcoredump.c       | 392 ++++++++++++++++++++++
 drivers/gpu/drm/xe/xe_devcoredump_types.h |  49 +++
 drivers/gpu/drm/xe/xe_device.h            |   5 +
 drivers/gpu/drm/xe/xe_guc_capture.c       |  58 +++-
 7 files changed, 536 insertions(+), 10 deletions(-)

-- 
2.43.0