drm/xe/mmio_gem: cache the dummy page per object

Currently, when the fault handler provides a dummy page, it
allocates a new one on every invocation and ties its lifetime to
the drm_device via drmm_add_action_or_reset(). Concurrent faults
after hot-unplug therefore accumulate pages that persist until
device teardown.

Cache a single dummy page in the xe_mmio_gem object and use dma_resv
lock to protect its allocation. Free it with the object.

v2: use dma_resv lock to protect the allocation (Matt Auld)

Assisted-by: GitHub-Copilot:claude-opus-4.6
Signed-off-by: Ilia Levi <ilia.levi@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patch.msgid.link/20260908165046.1393557-15-matthew.auld@intel.com
(cherry picked from commit 8bf6213f9831e46313af4722a1ee6db1b7596378)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

0 files changed, 0 insertions, 0 deletions