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authorPaul Mundt <lethal@linux-sh.org>2011-08-08 13:45:28 +0900
committerPaul Mundt <lethal@linux-sh.org>2011-08-08 13:45:28 +0900
commit77c7ee51a062bb595c501ec098125a68999c20c3 (patch)
treec5060ca5786ef353e005dae04b61d2c49967284d /arch/s390/mm/maccess.c
parent1ba762209491e2496e58baffa3fd65d661f54404 (diff)
parent322a8b034003c0d46d39af85bf24fee27b902f48 (diff)
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into sh-latest
Conflicts: drivers/tty/serial/sh-sci.c Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/s390/mm/maccess.c')
-rw-r--r--arch/s390/mm/maccess.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c
index 51e5cd9b906..5dbbaa6e594 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();
+}