[S390] Improve address space mode selection.
Introduce user_mode to replace the two variables switch_amode and
s390_noexec. There are three valid combinations of the old values:
1) switch_amode == 0 && s390_noexec == 0
2) switch_amode == 1 && s390_noexec == 0
3) switch_amode == 1 && s390_noexec == 1
They get replaced by
1) user_mode == HOME_SPACE_MODE
2) user_mode == PRIMARY_SPACE_MODE
3) user_mode == SECONDARY_SPACE_MODE
The new kernel parameter user_mode=[primary,secondary,home] lets
you choose the address space mode the user space processes should
use. In addition the CONFIG_S390_SWITCH_AMODE config option
is removed.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/mmu_context.h b/arch/s390/include/asm/mmu_context.h
index fc7edd6..976e273 100644
--- a/arch/s390/include/asm/mmu_context.h
+++ b/arch/s390/include/asm/mmu_context.h
@@ -36,7 +36,7 @@
mm->context.has_pgste = 1;
mm->context.alloc_pgste = 1;
} else {
- mm->context.noexec = s390_noexec;
+ mm->context.noexec = (user_mode == SECONDARY_SPACE_MODE);
mm->context.has_pgste = 0;
mm->context.alloc_pgste = 0;
}
@@ -58,7 +58,7 @@
pgd_t *pgd = mm->pgd;
S390_lowcore.user_asce = mm->context.asce_bits | __pa(pgd);
- if (switch_amode) {
+ if (user_mode != HOME_SPACE_MODE) {
/* Load primary space page table origin. */
pgd = mm->context.noexec ? get_shadow_table(pgd) : pgd;
S390_lowcore.user_exec_asce = mm->context.asce_bits | __pa(pgd);
diff --git a/arch/s390/include/asm/pgalloc.h b/arch/s390/include/asm/pgalloc.h
index ddad590..68940d0 100644
--- a/arch/s390/include/asm/pgalloc.h
+++ b/arch/s390/include/asm/pgalloc.h
@@ -143,7 +143,8 @@
spin_lock_init(&mm->context.list_lock);
INIT_LIST_HEAD(&mm->context.crst_list);
INIT_LIST_HEAD(&mm->context.pgtable_list);
- return (pgd_t *) crst_table_alloc(mm, s390_noexec);
+ return (pgd_t *)
+ crst_table_alloc(mm, user_mode == SECONDARY_SPACE_MODE);
}
#define pgd_free(mm, pgd) crst_table_free(mm, (unsigned long *) pgd)
diff --git a/arch/s390/include/asm/setup.h b/arch/s390/include/asm/setup.h
index e37478e..52a779c 100644
--- a/arch/s390/include/asm/setup.h
+++ b/arch/s390/include/asm/setup.h
@@ -49,17 +49,12 @@
void detect_memory_layout(struct mem_chunk chunk[]);
-#ifdef CONFIG_S390_SWITCH_AMODE
-extern unsigned int switch_amode;
-#else
-#define switch_amode (0)
-#endif
+#define PRIMARY_SPACE_MODE 0
+#define ACCESS_REGISTER_MODE 1
+#define SECONDARY_SPACE_MODE 2
+#define HOME_SPACE_MODE 3
-#ifdef CONFIG_S390_EXEC_PROTECT
-extern unsigned int s390_noexec;
-#else
-#define s390_noexec (0)
-#endif
+extern unsigned int user_mode;
/*
* Machine features detected in head.S