1 files changed, 42 insertions, 0 deletions
diff --git a/arch/s390/include/asm/fpu-insn.h b/arch/s390/include/asm/fpu-insn.h
new file mode 100644
index 000000000000..32d2894b60ca
--- /dev/null
+++ b/arch/s390/include/asm/fpu-insn.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Support for Floating Point and Vector Instructions
+ *
+ */
+
+#ifndef __ASM_S390_FPU_INSN_H
+#define __ASM_S390_FPU_INSN_H
+
+#include <asm/fpu-insn-asm.h>
+
+#ifndef __ASSEMBLY__
+
+#include <asm/asm-extable.h>
+
+asm(".include \"asm/fpu-insn-asm.h\"\n");
+
+/**
+ * sfpc_safe - Set floating point control register safely.
+ * @fpc: new value for floating point control register
+ *
+ * Set floating point control register. This may lead to an exception,
+ * since a saved value may have been modified by user space (ptrace,
+ * signal return, kvm registers) to an invalid value. In such a case
+ * set the floating point control register to zero.
+ */
+static inline void sfpc_safe(u32 fpc)
+{
+	asm volatile("\n"
+		"0:	sfpc	%[fpc]\n"
+		"1:	nopr	%%r7\n"
+		".pushsection .fixup, \"ax\"\n"
+		"2:	lghi	%[fpc],0\n"
+		"	jg	0b\n"
+		".popsection\n"
+		EX_TABLE(1b, 2b)
+		: [fpc] "+d" (fpc)
+		: : "memory");
+}
+
+#endif /* __ASSEMBLY__ */
+#endif	/* __ASM_S390_FPU_INSN_H */