[S390] s390: move machine flags to lowcore

Currently the storage of the machine flags is a globally exported unsigned
long long variable. By moving the storage location into the lowcore struct we
allow assembler code to check machine_flags directly even without needing a
register. Addtionally the lowcore and therefore the machine flags too will be
in cache most of the time.

Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index 4d221c81c849..d4e1e5b6cfda 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -34,6 +34,8 @@
 
 char kernel_nss_name[NSS_NAME_SIZE + 1];
 
+static unsigned long machine_flags;
+
 static void __init setup_boot_command_line(void);
 
 
@@ -391,5 +393,6 @@ void __init startup_init(void)
         setup_hpage();
         sclp_facilities_detect();
         detect_memory_layout(memory_chunk);
+        S390_lowcore.machine_flags = machine_flags;
         lockdep_on();
 }