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authorJiri Kosina <jkosina@suse.cz>2011-09-15 15:08:05 +0200
committerJiri Kosina <jkosina@suse.cz>2011-09-15 15:08:18 +0200
commite060c38434b2caa78efe7cedaff4191040b65a15 (patch)
tree407361230bf6733f63d8e788e4b5e6566ee04818 /arch/s390/mm/maccess.c
parentviacam: Don't explode if pci_find_bus() returns NULL (diff)
parentmm: account skipped entries to avoid looping in find_get_pages (diff)
downloadlinux-e060c38434b2caa78efe7cedaff4191040b65a15.tar.xz
linux-e060c38434b2caa78efe7cedaff4191040b65a15.zip
Merge branch 'master' into for-next
Fast-forward merge with Linus to be able to merge patches based on more recent version of the tree.
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 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();
+}