[igt-dev] [PATCH i-g-t v3 3/7] lib/intel_batchbuffer: Introduce intel_bb

[Chris Wilson]

Quoting Zbigniew Kempczyński (2020-05-18 10:09:15)
> +uint64_t intel_bb_get_presumed_offset(struct intel_bb *ibb, uint32_t handle)
> +{
> +       uint32_t i;
> +
> +       igt_assert(ibb);
> +
> +       for (i = 0; i < ibb->num_relocs; i++)
> +               if (ibb->relocs[i].target_handle == handle)
> +                       return ibb->relocs[i].presumed_offset;

The canonical source is execobj[].offset. The kernel always updates the
returned execobj[] with the correct information, but the reloc[] array
may be told a lie to force a relocation on the next pass.

The rule is address in batch matches that of reloc[].presumed_offset
that matches execobj[].offset. The latter being the linchpin.
-Chris