[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>

1 files changed, 6 insertions, 11 deletions

diff --git a/arch/s390/include/asm/setup.h b/arch/s390/include/asm/setup.h
index e37478e87286..52a779c337e8 100644
--- a/arch/s390/include/asm/setup.h
+++ b/arch/s390/include/asm/setup.h
@@ -49,17 +49,12 @@ extern unsigned long memory_end;
 
 void detect_memory_layout(struct mem_chunk chunk[]);
 
-#ifdef CONFIG_S390_SWITCH_AMODE
-extern unsigned int switch_amode;
-#else
-#define switch_amode    (0)
-#endif
-
-#ifdef CONFIG_S390_EXEC_PROTECT
-extern unsigned int s390_noexec;
-#else
-#define s390_noexec     (0)
-#endif
+#define PRIMARY_SPACE_MODE      0
+#define ACCESS_REGISTER_MODE    1
+#define SECONDARY_SPACE_MODE    2
+#define HOME_SPACE_MODE         3
+
+extern unsigned int user_mode;
 
 /*
  * Machine features detected in head.S