mem-map: Setup memory for MDDT table

Each entry in MDST and MDDT takes 16 bytes. With 1K we can have upto 64
entries. This is sufficient to support OPAL MPIPL (memory preserving IPL).

Presently OPAL reserves 2K memory for MDST table. Lets split this into two
region of 1K for MDST and MDDT table.

Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
[oliver: rebased]
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>

include/mem-map.h

@@ -36,12 +36,16 @@
  */
 #define PROCIN_OFF		(SPIRA_OFF + 0x800)
 
-/* Initial MDST table like PROCIN, we need fixed addresses,
+/* Initial MDST and MDDT tables like PROCIN, we need fixed addresses,
  * we leave a 2k gap for PROCIN
  */
 #define MDST_TABLE_OFF		(SPIRA_OFF + 0x1000)
+#define MDST_TABLE_SIZE		0x400
 
-/* Like MDST, we need fixed address for CPU control header.
+#define MDDT_TABLE_OFF		(SPIRA_OFF + 0x1400)
+#define MDDT_TABLE_SIZE		0x400
+
+/* Like MDST and MDDT, we need fixed address for CPU control header.
  * We leave a 2k gap for MDST. CPU_CTL table is of size ~4k
  */
 #define CPU_CTL_OFF             (SPIRA_OFF + 0x1800)

skiboot.lds.S

@@ -1,7 +1,5 @@
 // SPDX-License-Identifier: Apache-2.0
 /*
- * Skiboot linker script
- *
  * Copyright 2013-2019 IBM Corp.
  */
 
@@ -81,6 +79,11 @@ SECTIONS
 		KEEP(*(.mdst.data))
 	}
 
+	. = MDDT_TABLE_OFF;
+	.mddt : {
+		KEEP(*(.mddt.data))
+	}
+
 	. = CPU_CTL_OFF;
 	.cpuctrl : {
 		KEEP(*(.cpuctrl.data))