Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6

* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
  [S390] signal: use set_restore_sigmask() helper
  [S390] smp: remove pointless comments in startup_secondary()
  [S390] qdio: Use kstrtoul_from_user
  [S390] sclp_async: Use kstrtoul_from_user
  [S390] exec: remove redundant set_fs(USER_DS)
  [S390] cpu hotplug: on cpu start wait until being marked active
  [S390] signal: convert to use set_current_blocked()
  [S390] asm offsets: fix coding style
  [S390] Add support for IBM zEnterprise 114
  [S390] dasd: check if raw track access is supported
  [S390] Use diagnose 308 for system reset
  [S390] Export store_status() function
  [S390] dasd: use vmalloc for statistics input buffer
  [S390] Add PSW restart shutdown trigger
  [S390] missing return in page_table_alloc_pgste
  [S390] qdio: 2nd stage retry on SIGA-W busy conditions

1 files changed, 16 insertions, 0 deletions

diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c
index 51e5cd9b906a..5dbbaa6e594c 100644
--- a/arch/s390/mm/maccess.c
+++ b/arch/s390/mm/maccess.c
@@ -85,3 +85,19 @@ int memcpy_real(void *dest, void *src, size_t count)
 	arch_local_irq_restore(flags);
 	return rc;
 }
+
+/*
+ * Copy memory to absolute zero
+ */
+void copy_to_absolute_zero(void *dest, void *src, size_t count)
+{
+	unsigned long cr0;
+
+	BUG_ON((unsigned long) dest + count >= sizeof(struct _lowcore));
+	preempt_disable();
+	__ctl_store(cr0, 0, 0);
+	__ctl_clear_bit(0, 28); /* disable lowcore protection */
+	memcpy_real(dest + store_prefix(), src, count);
+	__ctl_load(cr0, 0, 0);
+	preempt_enable();
+}