[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>

3 files changed, 5 insertions, 3 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();
 }
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 06201b93cbbf..163bdfe5a6be 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -82,9 +82,6 @@ EXPORT_SYMBOL(console_devno);
 unsigned int console_irq = -1;
 EXPORT_SYMBOL(console_irq);
 
-unsigned long machine_flags;
-EXPORT_SYMBOL(machine_flags);
-
 unsigned long elf_hwcap = 0;
 char elf_platform[ELF_PLATFORM_SIZE];
 
@@ -426,6 +423,7 @@ setup_lowcore(void)
                 __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0) + PAGE_SIZE;
         lc->current_task = (unsigned long) init_thread_union.thread_info.task;
         lc->thread_info = (unsigned long) &init_thread_union;
+        lc->machine_flags = S390_lowcore.machine_flags;
 #ifndef CONFIG_64BIT
         if (MACHINE_HAS_IEEE) {
                 lc->extended_save_area_addr = (__u32)
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 006ed5016eb4..796630240715 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -571,6 +571,7 @@ int __cpuinit __cpu_up(unsigned int cpu)
         cpu_lowcore->current_task = (unsigned long) idle;
         cpu_lowcore->cpu_nr = cpu;
         cpu_lowcore->kernel_asce = S390_lowcore.kernel_asce;
+        cpu_lowcore->machine_flags = S390_lowcore.machine_flags;
         eieio();
 
         while (signal_processor(cpu, sigp_restart) == sigp_busy)