Zen-based AMD systems report DRAM ECC errors through Unified Memory
Controller (UMC) MCA banks. The value provided in MCA_ADDR is
a "normalized" address which represents the UMC's view of its managed
memory. The normalized address must be translated to a system physical
address for software to take action.

MI300 systems, uniquely, do not provide a normalized address in MCA_ADDR
for DRAM ECC errors. Rather, the "DRAM" address is reported. This value
includes identifiers for the bank, row, column, pseudochannel and stack
of the memory location.

The DRAM address must be converted to a normalized address in order to
be further translated to a system physical address.

Add helper functions to do the DRAM to normalized translation for MI300
systems. The method is based on the fixed hardware layout of the on-chip
memory.

  [ bp: Massage commit message, decapitalize some, rename function. ]
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Co-developed-by: Muralidhara M K <muralidhara.mk@amd.com>
Signed-off-by: Muralidhara M K <muralidhara.mk@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Muralidhara M K <muralidhara.mk@amd.com>
Link: https://lore.kernel.org/r/20240131165732.88297-1-yazen.ghannam@amd.com