[S390] dynamic page tables.
Add support for different number of page table levels dependent
on the highest address used for a process. This will cause a 31 bit
process to use a two level page table instead of the four level page
table that is the default after the pud has been introduced. Likewise
a normal 64 bit process will use three levels instead of four. Only
if a process runs out of the 4 tera bytes which can be addressed with
a three level page table the fourth level is dynamically added. Then
the process can use up to 8 peta byte.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/include/asm-s390/processor.h b/include/asm-s390/processor.h
index 5a21f45..51d8891 100644
--- a/include/asm-s390/processor.h
+++ b/include/asm-s390/processor.h
@@ -81,11 +81,12 @@
#ifndef __s390x__
#define STACK_TOP (1UL << 31)
+#define STACK_TOP_MAX (1UL << 31)
#else /* __s390x__ */
-#define STACK_TOP (1UL << (test_thread_flag(TIF_31BIT) ? 31:53))
+#define STACK_TOP (1UL << (test_thread_flag(TIF_31BIT) ? 31:42))
+#define STACK_TOP_MAX (1UL << 42)
#endif /* __s390x__ */
-#define STACK_TOP_MAX STACK_TOP
#endif
@@ -142,8 +143,6 @@
/*
* Do necessary setup to start up a new thread.
*/
-#ifndef __s390x__
-
#define start_thread(regs, new_psw, new_stackp) do { \
set_fs(USER_DS); \
regs->psw.mask = psw_user_bits; \
@@ -151,24 +150,6 @@
regs->gprs[15] = new_stackp ; \
} while (0)
-#else /* __s390x__ */
-
-#define start_thread(regs, new_psw, new_stackp) do { \
- set_fs(USER_DS); \
- regs->psw.mask = psw_user_bits; \
- regs->psw.addr = new_psw; \
- regs->gprs[15] = new_stackp; \
-} while (0)
-
-#define start_thread31(regs, new_psw, new_stackp) do { \
- set_fs(USER_DS); \
- regs->psw.mask = psw_user32_bits; \
- regs->psw.addr = new_psw; \
- regs->gprs[15] = new_stackp; \
-} while (0)
-
-#endif /* __s390x__ */
-
/* Forward declaration, a strange C thing */
struct task_struct;
struct mm_struct;