[PATCH] makedumpfile: s390x: Add 2GB frame support for page table walker

[Michael Holzheu]

On s390 the zEC12 machines support 2GB frames. In order to walk page
tables correctly add support to the page table walker function so it
detects 2GB frames.

Signed-off-by: Heiko Carstens <heiko.carstens at de.ibm.com>
Signed-off-by: Michael Holzheu <holzheu at linux.vnet.ibm.com>
---
 arch/s390x.c   |    6 ++++++
 makedumpfile.h |    1 +
 2 files changed, 7 insertions(+)

--- a/arch/s390x.c
+++ b/arch/s390x.c
@@ -247,6 +247,11 @@ vtop_s390x(unsigned long vaddr)
 			return NOT_PADDR;
 		}
 		table = entry & _REGION_ENTRY_ORIGIN;
+		if ((entry & _REGION_ENTRY_LARGE) && (level == 1)) {
+			table &= ~0x7fffffffUL;
+			paddr = table + (vaddr & 0x7ffffffUL);
+			return paddr;
+		}
 		len = RSG_TABLE_LENGTH(entry);
 		level--;
 	}
@@ -257,6 +262,7 @@ vtop_s390x(unsigned long vaddr)
 	 * if no, then get the page table entry using PX index.
 	 */
 	if (entry & _SEGMENT_ENTRY_LARGE) {
+		table &= ~_PAGE_BYTE_INDEX_MASK;
 		paddr = table + (vaddr &  _PAGE_BYTE_INDEX_MASK);
 	} else {
 		entry = _kl_pg_table_deref_s390x(vaddr,
--- a/makedumpfile.h
+++ b/makedumpfile.h
@@ -563,6 +563,7 @@ do { \
 #define _REGION_ENTRY_TYPE_MASK	0x0c	/* region table type mask */
 #define _REGION_ENTRY_INVALID	0x20	/* invalid region table entry */
 #define _REGION_ENTRY_LENGTH	0x03	/* region table length */
+#define _REGION_ENTRY_LARGE	0x400
 #define _REGION_OFFSET_MASK	0x7ffUL	/* region/segment table offset mask */
 
 #define RSG_TABLE_LEVEL(x)	(((x) & _REGION_ENTRY_TYPE_MASK) >> 2)