[S390] nmi: enable machine checks early

Until now machine checks for the swapper process of the IPL cpu are just
implicitly (and more or less accidently) enabled when the first time the
idle process goes into idle state and loads an enabled wait psw.
Before that machine checks are disabled.
So let's enable them explicitly in trap_init() so we have a well defined
time when machine checks are enabled.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c
index f6342ec084a4..4f0cecb4f9e0 100644
--- a/arch/s390/kernel/traps.c
+++ b/arch/s390/kernel/traps.c
@@ -733,4 +733,6 @@ void __init trap_init(void)
         pgm_check_table[0x15] = &operand_exception;
         pgm_check_table[0x1C] = &space_switch_exception;
         pgm_check_table[0x1D] = &hfp_sqrt_exception;
+        /* Enable machine checks early. */
+        local_mcck_enable();
 }