This effectively partially reverts 13fe43714c ("anv: Add helpers in
anv_allocator for mapping BOs") where we both added helpers and reworked
memory mapping to stash the maps on the BO. The problem comes with
external memory. Due to GEM rules, if a memory object is exported and
then imported or imported twice, we have to deduplicate the anv_bo
struct but, according to Vulkan rules, they are separate VkDeviceMemory
objects. This means we either need to always map whole objects and
reference-count the map or we need to handle maps separately for
separate VkDeviceMemory objects. For now, take the later path.
Fixes: 13fe43714c ("anv: Add helpers in anv_allocator for mapping BOs")
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/5612
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13795>
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