[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/arch/s390/kernel/binfmt_elf32.c b/arch/s390/kernel/binfmt_elf32.c
index f1e40ca..3e1c315 100644
--- a/arch/s390/kernel/binfmt_elf32.c
+++ b/arch/s390/kernel/binfmt_elf32.c
@@ -134,6 +134,7 @@
}
#include <asm/processor.h>
+#include <asm/pgalloc.h>
#include <linux/module.h>
#include <linux/elfcore.h>
#include <linux/binfmts.h>
@@ -183,6 +184,16 @@
#undef start_thread
#define start_thread start_thread31
+static inline void start_thread31(struct pt_regs *regs, unsigned long new_psw,
+ unsigned long new_stackp)
+{
+ set_fs(USER_DS);
+ regs->psw.mask = psw_user32_bits;
+ regs->psw.addr = new_psw;
+ regs->gprs[15] = new_stackp;
+ crst_table_downgrade(current->mm, 1UL << 31);
+}
+
MODULE_DESCRIPTION("Binary format loader for compatibility with 32bit Linux for S390 binaries,"
" Copyright 2000 IBM Corporation");
MODULE_AUTHOR("Gerhard Tonn <ton@de.ibm.com>");