We can use hsa_amd_agent_iterate_memory_pools to fetch info about GPU
memory pools in the GPU. HSA_AMD_SEGMENT_GROUP seems to be LDS, and
HSA_AMD_SEGMENT_GLOBAL seems to be global memory.
However, the latter is reported multiple times (I don't know why). The
only solution I found for this is to check for the
HSA_AMD_MEMORY_POOL_GLOBAL_FLAG_EXTENDED_SCOPE_FINE_GRAINED flag, which
seems to be reported only once.
For bus width, we simply use HSA_AMD_AGENT_INFO_MEMORY_WIDTH.