[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, 0 insertions, 15 deletions

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 16c673096a22..c80235206c01 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -220,23 +220,8 @@ config AUDIT_ARCH
         bool
         default y
 
-config S390_SWITCH_AMODE
-        bool "Switch kernel/user addressing modes"
-        help
-          This option allows to switch the addressing modes of kernel and user
-          space. The kernel parameter switch_amode=on will enable this feature,
-          default is disabled. Enabling this (via kernel parameter) on machines
-          earlier than IBM System z9-109 EC/BC will reduce system performance.
-
-          Note that this option will also be selected by selecting the execute
-          protection option below. Enabling the execute protection via the
-          noexec kernel parameter will also switch the addressing modes,
-          independent of the switch_amode kernel parameter.
-
-
 config S390_EXEC_PROTECT
         bool "Data execute protection"
-        select S390_SWITCH_AMODE
         help
           This option allows to enable a buffer overflow protection for user
           space programs and it also selects the addressing mode option above.