drm/xe: Clear scratch page on vm_bind

When a vm runs under fault mode, if scratch page is enabled, we need
to clear the scratch page mapping on vm_bind for the vm_bind address
range. Under fault mode, we depend on recoverable page fault to
establish mapping in page table. If scratch page is not cleared, GPU
access of address won't cause page fault because it always hits the
existing scratch page mapping.

When vm_bind with IMMEDIATE flag, there is no need of clearing as
immediate bind can overwrite the scratch page mapping.

So far only is xe2 and xe3 products are allowed to enable scratch page
under fault mode. On other platform we don't allow scratch page under
fault mode, so no need of such clearing.

v2: Rework vm_bind pipeline to clear scratch page mapping. This is similar
to a map operation, with the exception that PTEs are cleared instead of
pointing to valid physical pages. (Matt, Thomas)

TLB invalidation is needed after clear scratch page mapping as larger
scratch page mapping could be backed by physical page and cached in
TLB. (Matt, Thomas)

v3: Fix the case of clearing huge pte (Thomas)

Improve commit message (Thomas)

v4: TLB invalidation on all LR cases, not only the clear on bind
cases (Thomas)

v5: Misc cosmetic changes (Matt)
    Drop pt_update_ops.invalidate_on_bind. Directly wire
    xe_vma_op.map.invalidata_on_bind to bind_op_prepare/commit (Matt)

v6: checkpatch fix (Matt)

v7: No need to check platform needs_scratch deciding invalidate_on_bind
    (Matt)

v8: rebase
v9: rebase
v10: fix an error in xe_pt_stage_bind_entry, introduced in v9 rebase

Signed-off-by: Oak Zeng <oak.zeng@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Link: https://lore.kernel.org/r/20250403165328.2438690-3-oak.zeng@intel.com
Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>

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