1 files changed, 36 insertions, 0 deletions
diff --git a/arch/s390/include/asm/asce.h b/arch/s390/include/asm/asce.h
new file mode 100644
index 000000000000..f6dfaaba735a
--- /dev/null
+++ b/arch/s390/include/asm/asce.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _ASM_S390_ASCE_H
+#define _ASM_S390_ASCE_H
+
+#include <linux/thread_info.h>
+#include <linux/irqflags.h>
+#include <asm/lowcore.h>
+#include <asm/ctlreg.h>
+
+static inline bool enable_sacf_uaccess(void)
+{
+	unsigned long flags;
+
+	if (test_thread_flag(TIF_ASCE_PRIMARY))
+		return true;
+	local_irq_save(flags);
+	local_ctl_load(1, &get_lowcore()->kernel_asce);
+	set_thread_flag(TIF_ASCE_PRIMARY);
+	local_irq_restore(flags);
+	return false;
+}
+
+static inline void disable_sacf_uaccess(bool previous)
+{
+	unsigned long flags;
+
+	if (previous)
+		return;
+	local_irq_save(flags);
+	local_ctl_load(1, &get_lowcore()->user_asce);
+	clear_thread_flag(TIF_ASCE_PRIMARY);
+	local_irq_restore(flags);
+}
+
+#endif /* _ASM_S390_ASCE_H */