[S390] s390: use change recording override for kernel mapping
We dont need the dirty bit if a write access is done via the kernel
mapping. In that case SetPageDirty and friends are used anyway, no
need to do that a second time. We can use the change-recording
overide function for the kernel mapping, if available.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 60a7b1a..e2fa79c 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -169,12 +169,13 @@
* STL Segment-Table-Length: Segment-table length (STL+1*16 entries -> up to 2048)
*
* A 64 bit pagetable entry of S390 has following format:
- * | PFRA |0IP0| OS |
+ * | PFRA |0IPC| OS |
* 0000000000111111111122222222223333333333444444444455555555556666
* 0123456789012345678901234567890123456789012345678901234567890123
*
* I Page-Invalid Bit: Page is not available for address-translation
* P Page-Protection Bit: Store access not possible for page
+ * C Change-bit override: HW is not required to set change bit
*
* A 64 bit segmenttable entry of S390 has following format:
* | P-table origin | TT
@@ -218,6 +219,7 @@
*/
/* Hardware bits in the page table entry */
+#define _PAGE_CO 0x100 /* HW Change-bit override */
#define _PAGE_RO 0x200 /* HW read-only bit */
#define _PAGE_INVALID 0x400 /* HW invalid bit */