nds32: Signal handling support

This patch adds support for signal handling.
Signed-off-by: Vincent Chen <vincentc@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>

arch/nds32/include/uapi/asm/sigcontext.h

+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#ifndef _ASMNDS32_SIGCONTEXT_H
+#define _ASMNDS32_SIGCONTEXT_H
+
+/*
+ * Signal context structure - contains all info to do with the state
+ * before the signal handler was invoked.  Note: only add new entries
+ * to the end of the structure.
+ */
+
+struct zol_struct {
+	unsigned long nds32_lc;	/* $LC */
+	unsigned long nds32_le;	/* $LE */
+	unsigned long nds32_lb;	/* $LB */
+};
+
+struct sigcontext {
+	unsigned long trap_no;
+	unsigned long error_code;
+	unsigned long oldmask;
+	unsigned long nds32_r0;
+	unsigned long nds32_r1;
+	unsigned long nds32_r2;
+	unsigned long nds32_r3;
+	unsigned long nds32_r4;
+	unsigned long nds32_r5;
+	unsigned long nds32_r6;
+	unsigned long nds32_r7;
+	unsigned long nds32_r8;
+	unsigned long nds32_r9;
+	unsigned long nds32_r10;
+	unsigned long nds32_r11;
+	unsigned long nds32_r12;
+	unsigned long nds32_r13;
+	unsigned long nds32_r14;
+	unsigned long nds32_r15;
+	unsigned long nds32_r16;
+	unsigned long nds32_r17;
+	unsigned long nds32_r18;
+	unsigned long nds32_r19;
+	unsigned long nds32_r20;
+	unsigned long nds32_r21;
+	unsigned long nds32_r22;
+	unsigned long nds32_r23;
+	unsigned long nds32_r24;
+	unsigned long nds32_r25;
+	unsigned long nds32_fp;	/* $r28 */
+	unsigned long nds32_gp;	/* $r29 */
+	unsigned long nds32_lp;	/* $r30 */
+	unsigned long nds32_sp;	/* $r31 */
+	unsigned long nds32_ipc;
+	unsigned long fault_address;
+	unsigned long used_math_flag;
+	/* FPU Registers */
+	struct zol_struct zol;
+};
+
+#endif