EDAC/{skx_common,imh}: Add EDAC driver for Intel Diamond Rapids servers

Intel Diamond Rapids CPUs include Integrated Memory and I/O Hubs (IMH).
The memory controllers within the IMHs provide memory stacks to the
processor. Create a new driver for this IMH-based memory controllers
rather than applying additional patches to the existing i10nm_edac.c
for the following reasons:

1) The memory controllers are not presented as PCI devices; instead,
   the detection and all their registers have been transitioned to
   MMIO-based memory spaces.

2) Validation processes are costly. Modifications to i10nm_edac would
   require extensive validation checks against multiple platforms,
   including Ice Lake, Sapphire Rapids, Emerald Rapids, Granite Rapids,
   Sierra Forest, and Grand Ridge.

3) Future Intel CPUs will likely only need patches on top of this new
   EDAC driver. Validation can be limited to Diamond Rapids servers
   and future Intel CPU generations.

[Tony: Fix kerneldoc for struct local_reg]
[randconfig: Added dependencies on NFIT and DMI]

Tested-by: Yi Lai <yi1.lai@intel.com>
Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Link: https://patch.msgid.link/20251119134132.2389472-5-qiuxu.zhuo@intel.com

Author: qzhuo2

drivers/edac/Kconfig

@@ -283,6 +283,18 @@ config EDAC_I10NM
 	  system has non-volatile DIMMs you should also manually
 	  select CONFIG_ACPI_NFIT.
 
+config EDAC_IMH
+	tristate "Intel Integrated Memory/IO Hub MC"
+	depends on X86_64 && X86_MCE_INTEL && ACPI
+	depends on ACPI_NFIT || !ACPI_NFIT # if ACPI_NFIT=m, EDAC_IMH can't be y
+	select DMI
+	select ACPI_ADXL
+	help
+	  Support for error detection and correction the Intel
+	  Integrated Memory/IO Hub Memory Controller. This MC IP is
+	  first used on the Diamond Rapids servers but may appear on
+	  others in the future.
+
 config EDAC_PND2
 	tristate "Intel Pondicherry2"
 	depends on PCI && X86_64 && X86_MCE_INTEL

drivers/edac/Makefile

@@ -65,6 +65,9 @@ obj-$(CONFIG_EDAC_SKX)			+= skx_edac.o skx_edac_common.o
 i10nm_edac-y				:= i10nm_base.o
 obj-$(CONFIG_EDAC_I10NM)		+= i10nm_edac.o skx_edac_common.o
 
+imh_edac-y				:= imh_base.o
+obj-$(CONFIG_EDAC_IMH)			+= imh_edac.o skx_edac_common.o
+
 obj-$(CONFIG_EDAC_HIGHBANK_MC)		+= highbank_mc_edac.o
 obj-$(CONFIG_EDAC_HIGHBANK_L2)		+= highbank_l2_edac.o